Data base test

.gitattributes

@@ -34,4 +34,3 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.zst filter=lfs diff=lfs merge=lfs -text
 *tfevents* filter=lfs diff=lfs merge=lfs -text
 Roboto-VariableFont_wdth,wght.ttf filter=lfs diff=lfs merge=lfs -text
-1.png filter=lfs diff=lfs merge=lfs -text

Dockerfile

@@ -1,12 +1,31 @@
-FROM python:3.11-slim
-WORKDIR /app
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
-COPY . .
-RUN mkdir -p /data \
- && chmod -R 777 /data
-COPY web_invoice_store.json /data/web_invoice_store.json
-RUN chmod 666 /data/web_invoice_store.json
-ENV DATA_DIR=/data
-ENV PORT=7860
-CMD ["python", "server.py"]
+# syntax=docker/dockerfile:1
+FROM python:3.11-slim
+
+# System deps (jeśli używasz psycopg2-binary, wystarczy ca-certificates)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates curl && rm -rf /var/lib/apt/lists/*
+
+# Dobre praktyki
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV PYTHONUNBUFFERED=1
+
+# Nie-root user (HF i tak odpala jako uid 1000)
+RUN useradd -m appuser
+WORKDIR /app
+
+# Zależności
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Kod
+COPY . .
+
+# Entrypoint (migracje/init + start)
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+USER appuser
+EXPOSE 7860
+
+# UWAGA: zmienne ze Spaces (DATABASE_URL, itp.) będą dostępne dopiero w runtime
+ENTRYPOINT ["/entrypoint.sh"]

README.md

@@ -9,56 +9,87 @@ pinned: false
 
 # Generator faktur
 
-Projekt oferuje dwa sposoby tworzenia faktur: prostą aplikację CLI oraz rozbudowany panel webowy z backendem Flask i estetycznym PDF-em.
+Repozytorium zawiera dwa sposoby wystawiania faktur:
 
-## Co w środku?
-- **CLI** – szybkie narzędzie terminalowe do pojedynczych dokumentów.
-- **Frontend + backend** – logowanie, edycja danych firmy, inteligentny formularz nabywcy, historia faktur i eleganckie PDF-y z logo.
+1. prosta aplikacje CLI,
+2. rozbudowany frontend/ backend, ktory generuje faktury w PDF.
 
----
+## 1. Aplikacja CLI
 
-## Aplikacja webowa
+Niewielkie narzedzie w Pythonie, ktore pomaga zebrac podstawowe dane i wystawic fakture z pojedyncza pozycja (usluga lub towar). Dane firmy zapisywane sa lokalnie w `invoice_data.json`, a kazda wygenerowana faktura trafia do katalogu `invoices/`.
 
-### Wymagania
-- Python 3.8+
-- `pip install -r requirements.txt`
-- (opcjonalnie) `NEON_DATABASE_URL` – gdy ustawisz połączenie z bazą PostgreSQL/Neon, klienci i faktury są zapisywani w bazie zamiast w pliku.
+## Wymagania
+
+- Python 3.8 lub nowszy
+
+## Pierwsze uruchomienie
 
-### Uruchomienie
 ```powershell
-python server.py
-# aplikacja działa na http://localhost:5000
+python invoice_app.py
 ```
 
-### Funkcje
-- onboarding z konfiguracją firmy i logo,
-- logowanie z tokenem w `sessionStorage`,
-- edycja sprzedawcy i zarządzanie logo (PNG/JPG do 512 KB),
-- formularz nabywcy z wyszukiwarką (po nazwie lub NIP-ie, wyniki tylko z konta zalogowanego użytkownika),
-- dynamiczna tabela pozycji licząca netto/VAT/brutto oraz obsługę stawek 23/8/5/0/ZW/NP,
-- sekcja zwolnienia podatkowego i automatyczna nota prawna,
-- dashboard z filtrami dat, wykresem i historią ostatnich 200 faktur,
-- eksport PDF spójny z UI (logo nad sprzedawcą, kapsułki z sumami, czytelna tabela).
+1. Podaj dane firmy (nazwa, adres, NIP, numer konta).
+2. Ustaw haslo, ktore bedzie wymagane przy kolejnych uruchomieniach.
 
-> PDF-y generuje [jsPDF](https://cdnjs.com/libraries/jspdf) ładowany z CDN – przeglądarka musi mieć dostęp do internetu.
+Po zakonczeniu konfiguracji uruchom aplikacje ponownie, aby sie zalogowac i wystawic pierwsza fakture.
 
-### Reset danych
-- tryb plikowy: usuń `web_invoice_store.json`, aby przejść onboarding ponownie,
-- tryb Neon: wyczyść tabele w bazie lub użyj nowej bazy.
+## Wystawianie faktury
 
----
+```powershell
+python invoice_app.py
+```
 
-## Aplikacja CLI
+1. Zaloguj sie haslem ustawionym wczesniej.
+2. Podaj opis uslugi/towaru, ilosc oraz cene jednostkowa.
+3. Opcjonalnie wpisz dane klienta.
 
-Lekki kreator w terminalu zapisujący dokumenty do katalogu `invoices/` i historię w `invoice_data.json`.
+Aplikacja automatycznie policzy kwote netto i zapisze fakture w katalogu `invoices/` jako plik tekstowy (np. `invoices/FV-20240101-120000.txt`). Dane faktury sa rowniez dopisywane do pliku `invoice_data.json`, dzieki czemu latwo przechowywac historie.
+
+## 2. Aplikacja webowa (frontend + backend)
+
+Interfejs przegladarkowy z serwerem REST (Flask), ktory przechowuje dane firmy oraz historie faktur w pliku `web_invoice_store.json`.
+
+### Wymagania
+
+- Python 3.8+
+- Zainstalowany pakiet `Flask`
 
-### Uruchomienie
 ```powershell
-python invoice_app.py
+python -m pip install -r requirements.txt
 ```
-1. Przy pierwszym starcie wpisz dane firmy i ustaw hasło.
-2. Przy kolejnych startach logujesz się, uzupełniasz dane pozycji i (opcjonalnie) klienta.
-3. Utworzona faktura trafia do `invoices/`, a historia do pliku JSON.
 
-### Reset CLI
-Usuń katalog `invoices/` oraz plik `invoice_data.json`, aby rozpocząć od nowa (historia zostanie utracona).
+### Uruchomienie
+
+1. Start serwera API oraz statycznego frontendu:
+
+   ```powershell
+   python server.py
+   ```
+
+2. W przegladarce odwiedz `http://localhost:5000/`.
+
+### Funkcje webowego generatora
+
+- Pierwsze uruchomienie:
+  - konfiguracja danych sprzedawcy (nazwa, adres, kod pocztowy, miejscowosc, NIP, numer konta, haslo),
+  - dane przechowywane lokalnie na serwerze w `web_invoice_store.json`.
+- Logowanie chronione haslem (token przechowywany w `sessionStorage` przegladarki).
+- Panel po zalogowaniu:
+  - wyswietlenie danych sprzedawcy oraz mozliwosc edycji bezpośrednio z poziomu UI,
+  - formularz danych nabywcy z rozszerzonym adresem (ulica, kod pocztowy, miejscowosc, NIP),
+  - pole daty sprzedazy/wykonania uslugi (niezalezne od daty wystawienia),
+  - pozycje faktury z dynamiczna tabela: wprowadzamy cene brutto, wybieramy stawke VAT (23/8/5/0/ZW/NP), aplikacja automatycznie liczy cene netto, wartosc netto, VAT i brutto,
+  - obsluga pozycji zwolnionych (ZW) wraz z polem na podstawe prawna zwolnienia (wyswietlana na fakturze),
+  - podsumowanie stawek (np. 23% – X netto / VAT – Y, ZW – Z netto / VAT – 0) zamiast pojedynczej sumy netto,
+  - generowanie podgladu faktury oraz eksport do PDF w formacie A4 (NABYWCA po lewej, SPRZEDAWCA po prawej, tabela zgodna z nazewnictwem ustawy: „Cena jedn. netto”, „Wartosc netto (pozycja)”, „Stawka VAT”, „Kwota VAT (pozycja)”, „Wartosc brutto”).
+- Historia faktur zapisywana jest po stronie serwera (ostatnie 200 dokumentow).
+
+> **Uwaga:** do wygenerowania pliku PDF wykorzystywana jest biblioteka [jsPDF](https://cdnjs.com/libraries/jspdf) ladowana z CDN. Przegladarka musi miec dostep do internetu, aby pobrac skrypt.
+
+### Reset danych webowych
+
+Usun plik `web_invoice_store.json`, aby uruchomic konfiguracje od nowa (spowoduje to utrate historii faktur).
+
+## Reset danych CLI
+
+Jezeli chcesz rozpoczac konfiguracje od nowa, usun pliki `invoice_data.json` i katalog `invoices/` (uwaga: spowoduje to utrate historii wystawionych faktur).

db.py

@@ -1,265 +0,0 @@
-import os
-from contextlib import contextmanager
-from typing import Any, Dict, List, Optional, Sequence
-
-import psycopg2
-from psycopg2.extras import RealDictCursor
-
-DATABASE_URL = os.environ.get("NEON_DATABASE_URL")
-
-if not DATABASE_URL:
-    raise RuntimeError(
-        "Brak zmiennej NEON_DATABASE_URL. Ustaw sekret w Hugging Face lub "
-        "ustaw zmienną środowiskową lokalnie."
-    )
-
-
-
-@contextmanager
-def db_conn():
-    conn = psycopg2.connect(DATABASE_URL, cursor_factory=RealDictCursor)
-    try:
-        yield conn
-        conn.commit()
-    except Exception:
-        conn.rollback()
-        raise
-    finally:
-        conn.close()
-
-
-def fetch_one(query: str, params: Sequence[Any]) -> Optional[Dict[str, Any]]:
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(query, params)
-        return cur.fetchone()
-
-
-def fetch_all(query: str, params: Sequence[Any] = ()) -> List[Dict[str, Any]]:
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(query, params)
-        return cur.fetchall()
-
-
-def execute(query: str, params: Sequence[Any]) -> None:
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(query, params)
-
-
-def create_account(login: str, email: str, password_hash: str) -> int:
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(
-            """
-            INSERT INTO accounts (login, password_hash)
-            VALUES (%s, %s)
-            RETURNING id
-            """,
-            (login, password_hash),
-        )
-        account_id = cur.fetchone()["id"]
-        cur.execute(
-            """
-            INSERT INTO business_profiles (account_id, company_name, owner_name,
-                                           address_line, postal_code, city, tax_id, bank_account)
-            VALUES (%s, '', '', '', '', '', '', '')
-            """,
-            (account_id,),
-        )
-        return account_id
-
-
-def update_business(account_id: int, data: Dict[str, str]) -> None:
-    execute(
-        """
-        UPDATE business_profiles
-        SET company_name = %s,
-            owner_name = %s,
-            address_line = %s,
-            postal_code = %s,
-            city = %s,
-            tax_id = %s,
-            bank_account = %s
-        WHERE account_id = %s
-        """,
-        (
-            data["company_name"],
-            data["owner_name"],
-            data["address_line"],
-            data["postal_code"],
-            data["city"],
-            data["tax_id"],
-            data["bank_account"],
-            account_id,
-        ),
-    )
-
-
-
-def fetch_business_logo(account_id: int) -> Optional[Dict[str, Optional[str]]]:
-    row = fetch_one(
-        """
-        SELECT logo_mime_type, logo_data_base64
-        FROM business_profiles
-        WHERE account_id = %s
-        """,
-        (account_id,),
-    )
-    if not row:
-        return None
-    mime_type = row.get("logo_mime_type")
-    data_base64 = row.get("logo_data_base64")
-    if not mime_type or not data_base64:
-        return None
-    return {"mime_type": mime_type, "data": data_base64}
-
-
-def update_business_logo(account_id: int, mime: Optional[str], data_base64: Optional[str]) -> None:
-    execute(
-        """
-        UPDATE business_profiles
-        SET logo_mime_type = %s,
-            logo_data_base64 = %s
-        WHERE account_id = %s
-        """,
-        (mime, data_base64, account_id),
-    )
-
-def upsert_client(account_id: int, payload: Dict[str, str]) -> int:
-    row = fetch_one(
-        """
-        SELECT id FROM clients
-        WHERE account_id = %s AND tax_id = %s
-        """,
-        (account_id, payload["tax_id"]),
-    )
-    if row:
-        client_id = row["id"]
-        execute(
-            """
-            UPDATE clients
-            SET name = %s,
-                address_line = %s,
-                postal_code = %s,
-                city = %s,
-                phone = %s
-            WHERE id = %s
-            """,
-            (
-                payload["name"],
-                payload["address_line"],
-                payload["postal_code"],
-                payload["city"],
-                payload.get("phone"),
-                client_id,
-            ),
-        )
-        return client_id
-
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(
-            """
-            INSERT INTO clients (account_id, name, address_line, postal_code, city, tax_id, phone)
-            VALUES (%s, %s, %s, %s, %s, %s, %s)
-            RETURNING id
-            """,
-            (
-                account_id,
-                payload["name"],
-                payload["address_line"],
-                payload["postal_code"],
-                payload["city"],
-                payload["tax_id"],
-                payload.get("phone"),
-            ),
-        )
-        return cur.fetchone()["id"]
-
-
-def search_clients(account_id: int, term: str, limit: int = 10) -> List[Dict[str, Any]]:
-    query = (term or "").strip().lower()
-    like = f"%{query}%"
-    return fetch_all(
-        """
-        SELECT name, tax_id, address_line, postal_code, city, phone
-        FROM clients
-        WHERE account_id = %s
-          AND (
-            %s = '' OR
-            LOWER(COALESCE(name, '')) LIKE %s OR
-            LOWER(COALESCE(tax_id, '')) LIKE %s
-          )
-        ORDER BY LOWER(COALESCE(name, tax_id, '')) ASC
-        LIMIT %s
-        """,
-        (account_id, query, like, like, limit),
-    )
-
-
-def insert_invoice(account_id: int, client_id: int, invoice: Dict[str, Any]) -> int:
-    with db_conn() as conn, conn.cursor() as cur:
-        cur.execute(
-            """
-            INSERT INTO invoices (account_id, client_id, invoice_number, issued_at,
-                                  sale_date, payment_term_days, exemption_note,
-                                  total_net, total_vat, total_gross)
-            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
-            RETURNING id
-            """,
-            (
-                account_id,
-                client_id,
-                invoice["invoice_id"],
-                invoice["issued_at"],
-                invoice["sale_date"],
-                invoice.get("payment_term", 14),
-                invoice.get("exemption_note"),
-                invoice["totals"]["net"],
-                invoice["totals"]["vat"],
-                invoice["totals"]["gross"],
-            ),
-        )
-        invoice_id = cur.fetchone()["id"]
-
-        cur.executemany(
-            """
-            INSERT INTO invoice_items (invoice_id, line_no, name, quantity, unit,
-                                       vat_code, vat_label, unit_price_net,
-                                       unit_price_gross, net_total, vat_amount, gross_total)
-            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
-            """,
-            [
-                (
-                    invoice_id,
-                    idx + 1,
-                    item["name"],
-                    item["quantity"],
-                    item.get("unit"),
-                    item.get("vat_code"),
-                    item.get("vat_label"),
-                    item["unit_price_net"],
-                    item["unit_price_gross"],
-                    item["net_total"],
-                    item["vat_amount"],
-                    item["gross_total"],
-                )
-                for idx, item in enumerate(invoice["items"])
-            ],
-        )
-
-        cur.executemany(
-            """
-            INSERT INTO invoice_vat_summary (invoice_id, vat_label, net_total, vat_total, gross_total)
-            VALUES (%s, %s, %s, %s, %s)
-            """,
-            [
-                (
-                    invoice_id,
-                    row["vat_label"],
-                    row["net_total"],
-                    row["vat_total"],
-                    row["gross_total"],
-                )
-                for row in invoice["summary"]
-            ],
-        )
-
-        return invoice_id

entrypoint.sh

@@ -1,27 +1,27 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-# /data jest montowane przez HF; jeśli nie mamy uprawnień, pomiń
-if [ ! -d /data ]; then
-  echo "Info: /data not available (will be mounted by Spaces)."
-fi
-
-: "${DATABASE_URL:?ERROR: DATABASE_URL is not set}"
-
-python - <<'PY'
-import os
-from sqlalchemy import create_engine, text
-engine = create_engine(os.environ["DATABASE_URL"], pool_pre_ping=True)
-with engine.begin() as conn:
-    conn.execute(text("""
-        CREATE TABLE IF NOT EXISTS notes (
-            id SERIAL PRIMARY KEY,
-            body TEXT NOT NULL,
-            created_at TIMESTAMPTZ DEFAULT now()
-        )
-    """))
-PY
-
-# Start aplikacji – dopasuj do swojej
-exec python server.py
-# (albo: exec python server.py)
+#!/usr/bin/env bash
+set -euo pipefail
+
+# /data jest montowane przez HF; jeśli nie mamy uprawnień, pomiń
+if [ ! -d /data ]; then
+  echo "Info: /data not available (will be mounted by Spaces)."
+fi
+
+: "${DATABASE_URL:?ERROR: DATABASE_URL is not set}"
+
+python - <<'PY'
+import os
+from sqlalchemy import create_engine, text
+engine = create_engine(os.environ["DATABASE_URL"], pool_pre_ping=True)
+with engine.begin() as conn:
+    conn.execute(text("""
+        CREATE TABLE IF NOT EXISTS notes (
+            id SERIAL PRIMARY KEY,
+            body TEXT NOT NULL,
+            created_at TIMESTAMPTZ DEFAULT now()
+        )
+    """))
+PY
+
+# Start aplikacji – dopasuj do swojej
+exec python server.py
+# (albo: exec python server.py)

gitattributes

@@ -1,36 +0,0 @@
-*.7z filter=lfs diff=lfs merge=lfs -text
-*.arrow filter=lfs diff=lfs merge=lfs -text
-*.bin filter=lfs diff=lfs merge=lfs -text
-*.bz2 filter=lfs diff=lfs merge=lfs -text
-*.ckpt filter=lfs diff=lfs merge=lfs -text
-*.ftz filter=lfs diff=lfs merge=lfs -text
-*.gz filter=lfs diff=lfs merge=lfs -text
-*.h5 filter=lfs diff=lfs merge=lfs -text
-*.joblib filter=lfs diff=lfs merge=lfs -text
-*.lfs.* filter=lfs diff=lfs merge=lfs -text
-*.mlmodel filter=lfs diff=lfs merge=lfs -text
-*.model filter=lfs diff=lfs merge=lfs -text
-*.msgpack filter=lfs diff=lfs merge=lfs -text
-*.npy filter=lfs diff=lfs merge=lfs -text
-*.npz filter=lfs diff=lfs merge=lfs -text
-*.onnx filter=lfs diff=lfs merge=lfs -text
-*.ot filter=lfs diff=lfs merge=lfs -text
-*.parquet filter=lfs diff=lfs merge=lfs -text
-*.pb filter=lfs diff=lfs merge=lfs -text
-*.pickle filter=lfs diff=lfs merge=lfs -text
-*.pkl filter=lfs diff=lfs merge=lfs -text
-*.pt filter=lfs diff=lfs merge=lfs -text
-*.pth filter=lfs diff=lfs merge=lfs -text
-*.rar filter=lfs diff=lfs merge=lfs -text
-*.safetensors filter=lfs diff=lfs merge=lfs -text
-saved_model/**/* filter=lfs diff=lfs merge=lfs -text
-*.tar.* filter=lfs diff=lfs merge=lfs -text
-*.tar filter=lfs diff=lfs merge=lfs -text
-*.tflite filter=lfs diff=lfs merge=lfs -text
-*.tgz filter=lfs diff=lfs merge=lfs -text
-*.wasm filter=lfs diff=lfs merge=lfs -text
-*.xz filter=lfs diff=lfs merge=lfs -text
-*.zip filter=lfs diff=lfs merge=lfs -text
-*.zst filter=lfs diff=lfs merge=lfs -text
-*tfevents* filter=lfs diff=lfs merge=lfs -text
-Roboto-VariableFont_wdth,wght.ttf filter=lfs diff=lfs merge=lfs -text

index.html

@@ -1,390 +0,0 @@
-<!DOCTYPE html>
-<html lang="pl"><head>
-
-  <meta charset="UTF-8">
-  <meta name="viewport" content="width=device-width, initial-scale=1.0">
-  <title>Generator faktur</title>
-  <link rel="preconnect" href="https://fonts.googleapis.com">
-  <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
-  <link href="https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;600;700&display=swap" rel="stylesheet">
-  <link rel="stylesheet" href="styles.css">
-
-  
-  </head><body>
-  <main class="container">
-    <div class="brand-banner">
-      <img src="small_logotyp do strony.jpg" alt="Logotyp FakturON!" class="brand-logo">
-    </div>
-
-    <section id="hero-panel" class="panel hero-panel">
-      <div class="hero-columns">
-        <div class="hero-content">
-          <p class="eyebrow">Bezpłatny panel faktur</p>
-          <h1 class="app-title">Generator faktur</h1>
-          <p class="app-description">
-            Proste narzędzie do wystawiania i analizowania faktur: logujesz się, uzupełniasz dane kontrahenta,
-            zapisujesz dokument i od razu widzisz efekty w dashboardzie. Zero opłat, zero limitów.
-          </p>
-          <p class="hero-lead">
-            Cały proces zamyka się w jednym widoku – formularze, podgląd i historia korzystają z tej samej siatki,
-            dzięki czemu wyglądają identycznie na desktopie i na telefonie.
-          </p>
-          <ul class="header-highlights">
-            <li>
-              <strong>Zawsze bezpłatnie</strong>
-              <span>Generator działa bez limitów dokumentów i bez pakietów abonamentowych.</span>
-            </li>
-            <li>
-              <strong>Szybkie wystawianie</strong>
-              <span>W jednym formularzu zbierasz dane sprzedawcy, nabywcy i pozycje, a podgląd generuje się automatycznie.</span>
-            </li>
-            <li>
-              <strong>Spójny wygląd</strong>
-              <span>Każdy etap korzysta z tej samej siatki, więc łatwo pracować na desktopie i na telefonie.</span>
-            </li>
-            <li>
-              <strong>Dashboard i historia</strong>
-              <span>Po zalogowaniu od razu widać statystyki i listę faktur gotowych do pobrania.</span>
-            </li>
-          </ul>
-        </div>
-        <section id="auth-section" class="auth-panel">
-          <div class="auth-panel-header">
-            <p class="eyebrow">Logowanie</p>
-            <h2 class="auth-headline">Wejdź do generatora</h2>
-            <p class="auth-copy">Zaloguj się i prowadź całą obsługę faktur w jednym darmowym panelu.</p>
-          </div>
-          <div class="auth-login">
-            <div class="auth-card login-card">
-              <h3>Zaloguj się</h3>
-              <form id="login-form" class="form">
-                <label>
-                  Email
-                  <input type="email" name="email" autocomplete="email" required>
-                </label>
-                <label>
-                  Hasło
-                  <input type="password" name="password" autocomplete="current-password" required>
-                </label>
-                <button type="submit">Zaloguj</button>
-                <hr class="form-divider">
-              </form>
-              <p id="login-feedback" class="feedback" aria-live="polite"></p>
-              <div class="auth-actions">
-                <span>Nie masz konta?</span>
-                <button id="show-register-button" type="button" class="ghost-button">Stwórz konto</button>
-              </div>
-              <p id="legacy-login-hint" class="hint hidden"></p>
-            </div>
-          </div>
-        </section>
-      </div>
-    </section>
-
-    <section id="register-section" class="panel hidden">
-      <div class="auth-card register-card">
-        <div class="register-header">
-          <h3>Załóż konto</h3>
-          <button id="back-to-login" type="button" class="link-button">Wróć do logowania</button>
-        </div>
-        <form id="register-form" class="form">
-          <div class="register-fields">
-            <div class="field-grid register-credentials">
-              <label>
-                Email
-                <input type="email" name="email" autocomplete="email" required>
-              </label>
-              <label>
-                Hasło
-                <input type="password" name="password" autocomplete="new-password" required>
-              </label>
-              <label>
-                Powtórz hasło
-                <input type="password" name="confirm_password" autocomplete="new-password" required>
-              </label>
-            </div>
-
-            <div class="field-grid register-company">
-              <label>
-                Nazwa firmy
-                <input type="text" name="company_name" required>
-              </label>
-              <label>
-                Imię i nazwisko właściciela
-                <input type="text" name="owner_name" required>
-              </label>
-              <label>
-                Ulica i numer
-                <input type="text" name="address_line" required>
-              </label>
-              <label>
-                Kod pocztowy
-                <input type="text" name="postal_code" required>
-              </label>
-              <label>
-                Miejscowość
-                <input type="text" name="city" required>
-              </label>
-              <label>
-                NIP
-                <input type="text" name="tax_id" required>
-              </label>
-              <label>
-                Numer konta bankowego
-                <input type="text" name="bank_account" required>
-              </label>
-            </div>
-          </div>
-          <div class="form-actions">
-            <button type="submit">Utwórz konto</button>
-            <button id="cancel-register" type="button" class="link-button">Anuluj</button>
-          </div>
-        </form>
-        <p id="register-feedback" class="feedback"></p>
-        <p class="hint">Wskazowka: dane firmy zaktualizujesz pozniej w sekcji "Dane sprzedawcy".</p>
-      </div>
-    </section>
-
-    <section id="app-section" class="panel hidden">
-      <header class="app-header">
-        <div>
-          <h2>Panel faktur</h2>
-        </div>
-        <div id="login-badge" class="login-badge hidden" aria-live="polite">
-          <span class="badge-label">Zalogowany jako</span>
-          <span id="current-login-label" class="badge-value"></span>
-        </div>
-        <nav class="app-nav">
-          <button type="button" class="app-nav-button active" data-view="invoice-builder">Nowa faktura</button>
-          <button type="button" class="app-nav-button" data-view="dashboard">Dashboard</button>
-        </nav>
-        <button id="logout-button" type="button" class="link-button">Wyloguj</button>
-      </header>
-
-      <section id="invoice-builder-section" class="app-view">
-        <section class="business-section">
-          <div class="business-section-header">
-            <h3>Dane sprzedawcy</h3>
-            <div class="business-actions">
-              <button id="toggle-business-form" type="button" class="pill-button">Edycja danych</button>
-              <label for="logo-input" class="pill-button secondary">
-                <input id="logo-input" type="file" accept="image/png,image/jpeg" hidden>
-                Wgraj logo
-              </label>
-              <button id="remove-logo-button" type="button" class="pill-button danger hidden">Usuń logo</button>
-            </div>
-          </div>
-          <div id="business-display" class="business-display"></div>
-          <div id="logo-preview" class="logo-preview hidden">
-            <span class="logo-preview-label">Logo sprzedawcy</span>
-            <img id="logo-preview-image" alt="Logo firmy">
-          </div>
-          <p id="logo-feedback" class="feedback"></p>
-          <form id="business-form" class="form hidden">
-            <div class="field-grid">
-              <label>
-                Nazwa firmy
-                <input type="text" name="company_name" required>
-              </label>
-              <label>
-                Imię i nazwisko właściciela
-                <input type="text" name="owner_name" required>
-              </label>
-              <label>
-                Ulica i numer
-                <input type="text" name="address_line" required>
-              </label>
-              <label>
-                Kod pocztowy
-                <input type="text" name="postal_code" required>
-              </label>
-              <label>
-                Miejscowość
-                <input type="text" name="city" required>
-              </label>
-              <label>
-                NIP
-                <input type="text" name="tax_id" required>
-              </label>
-              <label>
-                Numer konta bankowego
-                <input type="text" name="bank_account" required>
-              </label>
-            </div>
-            <div class="form-actions">
-              <button type="submit">Zapisz</button>
-              <button id="cancel-business-update" type="button" class="link-button">Anuluj</button>
-            </div>
-            <p id="business-feedback" class="feedback"></p>
-          </form>
-        </section>
-
-        <form id="invoice-form" class="form">
-          <fieldset>
-            <legend>Informacje o fakturze</legend>
-            <div class="field-grid">
-              <label>
-                Data sprzedaży / wykonania usługi
-                <input type="date" name="saleDate">
-              </label>
-              <label>
-                Termin płatności (dni)
-                <input type="number" name="paymentTerm" min="1" step="1" value="14">
-              </label>
-            </div>
-          </fieldset>
-
-        <fieldset>
-          <legend>Dane nabywcy</legend>
-          <div class="client-lookup">
-            <label for="client-search">
-              Szybkie wyszukiwanie nabywcy
-              <input type="text" id="client-search" placeholder="Wpisz NIP lub nazwę klienta">
-            </label>
-            <div id="client-suggestions" class="client-suggestions hidden" role="listbox"></div>
-          </div>
-          <div class="field-grid">
-            <label>
-              Nazwa / Imię i nazwisko
-              <input type="text" name="clientName">
-            </label>
-              <label>
-                NIP
-                <input type="text" name="clientTaxId">
-              </label>
-              <label>
-                Ulica i numer
-                <input type="text" name="clientAddress">
-              </label>
-              <label>
-                Kod pocztowy
-                <input type="text" name="clientPostalCode">
-              </label>
-              <label>
-                Miejscowość
-                <input type="text" name="clientCity">
-              </label>
-              <label>
-                Numer telefonu
-                <input type="tel" name="clientPhone">
-              </label>
-            </div>
-          </fieldset>
-
-          <section class="items-section">
-            <header class="items-header">
-              <h3>Pozycje faktury</h3>
-              <button type="button" id="add-item-button">Dodaj pozycję</button>
-            </header>
-            <div class="items-table-wrapper">
-              <table class="items-table">
-                <thead>
-                  <tr>
-                    <th>Nazwa towaru/usługi</th>
-                    <th>Ilość</th>
-                    <th>Jednostka</th>
-                    <th>Cena jedn. brutto (PLN)</th>
-                    <th>Stawka VAT</th>
-                    <th>Wartość brutto (PLN)</th>
-                    <th></th>
-                  </tr>
-                </thead>
-                <tbody id="items-body"></tbody>
-              </table>
-            </div>
-          </section>
-
-          <div id="totals-container" class="totals">
-            <span id="total-net">Suma netto: 0.00 PLN</span>
-            <span id="total-vat">Kwota VAT: 0.00 PLN</span>
-            <span id="total-gross">Suma brutto: 0.00 PLN</span>
-          </div>
-
-          <section id="rate-summary" class="rate-summary"></section>
-
-          <div id="exemption-note-wrapper" class="hidden">
-            <label for="exemption-reason">Powód zastosowania stawki ZW/0%</label>
-            <select id="exemption-reason" class="form-select">
-              <option value="">Wybierz podstawę zwolnienia...</option>
-            </select>
-            <label for="exemption-note" id="exemption-note-label">Podstawa prawna zwolnienia</label>
-            <textarea id="exemption-note" rows="3" placeholder="np. Art. 43 ust. 1 pkt 19 ustawy o VAT"></textarea>
-          </div>
-
-          <div class="form-actions">
-            <button type="submit" id="save-invoice-button">Generuj fakturę</button>
-            <button id="cancel-edit-invoice" type="button" class="link-button hidden">Anuluj edycję</button>
-          </div>
-        </form>
-
-        <section id="invoice-result" class="panel hidden">
-          <h3>Podgląd faktury</h3>
-          <div id="invoice-output" class="invoice-preview"></div>
-          <button id="download-button" type="button">Pobierz jako plik PDF</button>
-        </section>
-      </section>
-
-      <section id="dashboard-section" class="app-view hidden">
-        <header class="dashboard-header">
-          <div class="filters">
-            <label>
-              Od
-              <input type="date" id="filter-start-date">
-            </label>
-            <label>
-              Do
-              <input type="date" id="filter-end-date">
-            </label>
-            <button type="button" id="clear-filters" class="button secondary">Wyczyść</button>
-          </div>
-          <p id="dashboard-feedback" class="feedback"></p>
-        </header>
-
-        <section class="dashboard-summary">
-          <div class="summary-card">
-            <span class="summary-label">Ostatnie 30 dni</span>
-            <span id="summary-month-count" class="summary-count">0 faktur</span>
-            <span id="summary-month-amount" class="summary-amount">0.00 PLN</span>
-          </div>
-          <div class="summary-card">
-            <span class="summary-label">Bieżący kwartał</span>
-            <span id="summary-quarter-count" class="summary-count">0 faktur</span>
-            <span id="summary-quarter-amount" class="summary-amount">0.00 PLN</span>
-          </div>
-          <div class="summary-card">
-            <span class="summary-label">Bieżący rok</span>
-            <span id="summary-year-count" class="summary-count">0 faktur</span>
-            <span id="summary-year-amount" class="summary-amount">0.00 PLN</span>
-          </div>
-        </section>
-
-        <section class="dashboard-chart">
-          <canvas id="invoices-chart" aria-label="Podsumowanie faktur"></canvas>
-        </section>
-
-        <section class="dashboard-table">
-          <div class="items-table-wrapper">
-            <table class="items-table">
-              <thead>
-                <tr>
-                  <th>Numer</th>
-                  <th>Data wystawienia</th>
-                  <th>Nabywca</th>
-                  <th>Suma brutto</th>
-                  <th>Akcje</th>
-                </tr>
-              </thead>
-              <tbody id="invoices-table-body"></tbody>
-            </table>
-            <p id="invoices-empty" class="hint hidden">Brak faktur do wyświetlenia.</p>
-          </div>
-        </section>
-      </section>
-    </section>
-  </main>
-
-  <script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/2.5.1/jspdf.umd.min.js" defer></script>
-  <script src="https://cdn.jsdelivr.net/npm/chart.js@4.4.6/dist/chart.umd.min.js" defer></script>
-  <script src="main.js" defer></script>
-</body>
-</html>

invoice_app.py

@@ -1,190 +1,190 @@
-import getpass
-import hashlib
-import json
-import os
-from datetime import datetime
-
-DATA_FILE = "invoice_data.json"
-INVOICE_FOLDER = "invoices"
-
-
-def hash_password(password: str) -> str:
-    return hashlib.sha256(password.encode("utf-8")).hexdigest()
-
-
-def prompt_non_empty(prompt: str) -> str:
-    while True:
-        value = input(prompt).strip()
-        if value:
-            return value
-        print("Pole nie moze byc puste.")
-
-
-def prompt_positive_float(prompt: str) -> float:
-    while True:
-        raw_value = input(prompt).replace(",", ".").strip()
-        try:
-            value = float(raw_value)
-        except ValueError:
-            print("Wprowadz liczbe.")
-            continue
-        if value <= 0:
-            print("Wartosc musi byc wieksza od zera.")
-            continue
-        return value
-
-
-def load_data():
-    if not os.path.exists(DATA_FILE):
-        return None
-    with open(DATA_FILE, "r", encoding="utf-8") as handle:
-        return json.load(handle)
-
-
-def save_data(data) -> None:
-    with open(DATA_FILE, "w", encoding="utf-8") as handle:
-        json.dump(data, handle, indent=2, ensure_ascii=False)
-
-
-def run_setup():
-    print("=== Konfiguracja konta przedsiebiorcy ===")
-    business = {
-        "company_name": prompt_non_empty("Nazwa firmy: "),
-        "owner_name": prompt_non_empty("Imie i nazwisko wlasciciela: "),
-        "address": prompt_non_empty("Adres: "),
-        "tax_id": prompt_non_empty("NIP: "),
-        "bank_account": prompt_non_empty("Numer konta bankowego: "),
-    }
-
-    print("\nUstaw haslo do logowania.")
-    while True:
-        password = getpass.getpass("Haslo: ")
-        confirm = getpass.getpass("Powtorz haslo: ")
-        if not password:
-            print("Haslo nie moze byc puste.")
-            continue
-        if password != confirm:
-            print("Hasla nie sa identyczne. Sprobuj ponownie.")
-            continue
-        break
-
-    data = {
-        "business": business,
-        "password_hash": hash_password(password),
-        "invoices": [],
-    }
-    save_data(data)
-    print("\nDane zapisane. Uruchom aplikacje ponownie, aby zalogowac sie i wystawiac faktury.")
-
-
-def authenticate(data) -> bool:
-    for attempt in range(3):
-        password = getpass.getpass("Haslo: ")
-        if hash_password(password) == data["password_hash"]:
-            return True
-        print("Nieprawidlowe haslo.")
-    return False
-
-
-def prompt_client_details():
-    answer = input("Dodac dane klienta? (T/N): ").strip().lower()
-    if answer not in ("t", "tak"):
-        return {}
-    print("\n=== Dane klienta ===")
-    client = {
-        "name": prompt_non_empty("Nazwa / Imie i nazwisko: "),
-        "address": prompt_non_empty("Adres: "),
-        "tax_id": input("NIP (opcjonalnie): ").strip(),
-    }
-    return client
-
-
-def format_invoice_text(invoice_id: str, business: dict, invoice: dict) -> str:
-    lines = [
-        f"Faktura: {invoice_id}",
-        f"Data wystawienia: {invoice['issued_at']}",
-        "",
-        "=== Sprzedawca ===",
-        f"Nazwa: {business['company_name']}",
-        f"Wlasciciel: {business['owner_name']}",
-        f"Adres: {business['address']}",
-        f"NIP: {business['tax_id']}",
-        f"Konto bankowe: {business['bank_account']}",
-        "",
-        "=== Nabywca ===",
-    ]
-
-    client = invoice.get("client", {})
-    if client:
-        lines.extend(
-            [
-                f"Nazwa: {client.get('name', '')}",
-                f"Adres: {client.get('address', '')}",
-                f"NIP: {client.get('tax_id', '') or '---'}",
-            ]
-        )
-    else:
-        lines.append("Brak danych klienta (pole opcjonalne).")
-
-    lines.extend(
-        [
-            "",
-            "=== Pozycja ===",
-            f"Opis: {invoice['item_description']}",
-            f"Ilosc: {invoice['quantity']}",
-            f"Cena jednostkowa: {invoice['unit_price']:.2f} PLN",
-            f"Wartosc netto: {invoice['net_total']:.2f} PLN",
-        ]
-    )
-    return "\n".join(lines)
-
-
-def create_invoice(data):
-    print("\n=== Wystaw fakture ===")
-    description = prompt_non_empty("Opis uslugi / towaru: ")
-    quantity = prompt_positive_float("Ilosc: ")
-    unit_price = prompt_positive_float("Cena jednostkowa (PLN): ")
-    client = prompt_client_details()
-
-    issued_at = datetime.now().strftime("%Y-%m-%d %H:%M")
-    invoice_id = datetime.now().strftime("FV-%Y%m%d-%H%M%S")
-    net_total = quantity * unit_price
-
-    invoice = {
-        "invoice_id": invoice_id,
-        "issued_at": issued_at,
-        "item_description": description,
-        "quantity": quantity,
-        "unit_price": unit_price,
-        "net_total": net_total,
-        "client": client,
-    }
-
-    os.makedirs(INVOICE_FOLDER, exist_ok=True)
-    invoice_path = os.path.join(INVOICE_FOLDER, f"{invoice_id}.txt")
-    with open(invoice_path, "w", encoding="utf-8") as handle:
-        handle.write(format_invoice_text(invoice_id, data["business"], invoice))
-
-    data["invoices"].append(invoice)
-    save_data(data)
-
-    print(f"\nFaktura zapisana do {invoice_path}")
-    print(f"Suma do zaplaty: {net_total:.2f} PLN")
-
-
-def main():
-    data = load_data()
-    if data is None:
-        run_setup()
-        return
-
-    print("=== Logowanie ===")
-    if not authenticate(data):
-        print("Zbyt wiele nieudanych prob logowania. Zakonczono.")
-        return
-
-    create_invoice(data)
-
-
-if __name__ == "__main__":
-    main()
+import getpass
+import hashlib
+import json
+import os
+from datetime import datetime
+
+DATA_FILE = "invoice_data.json"
+INVOICE_FOLDER = "invoices"
+
+
+def hash_password(password: str) -> str:
+    return hashlib.sha256(password.encode("utf-8")).hexdigest()
+
+
+def prompt_non_empty(prompt: str) -> str:
+    while True:
+        value = input(prompt).strip()
+        if value:
+            return value
+        print("Pole nie moze byc puste.")
+
+
+def prompt_positive_float(prompt: str) -> float:
+    while True:
+        raw_value = input(prompt).replace(",", ".").strip()
+        try:
+            value = float(raw_value)
+        except ValueError:
+            print("Wprowadz liczbe.")
+            continue
+        if value <= 0:
+            print("Wartosc musi byc wieksza od zera.")
+            continue
+        return value
+
+
+def load_data():
+    if not os.path.exists(DATA_FILE):
+        return None
+    with open(DATA_FILE, "r", encoding="utf-8") as handle:
+        return json.load(handle)
+
+
+def save_data(data) -> None:
+    with open(DATA_FILE, "w", encoding="utf-8") as handle:
+        json.dump(data, handle, indent=2, ensure_ascii=False)
+
+
+def run_setup():
+    print("=== Konfiguracja konta przedsiebiorcy ===")
+    business = {
+        "company_name": prompt_non_empty("Nazwa firmy: "),
+        "owner_name": prompt_non_empty("Imie i nazwisko wlasciciela: "),
+        "address": prompt_non_empty("Adres: "),
+        "tax_id": prompt_non_empty("NIP: "),
+        "bank_account": prompt_non_empty("Numer konta bankowego: "),
+    }
+
+    print("\nUstaw haslo do logowania.")
+    while True:
+        password = getpass.getpass("Haslo: ")
+        confirm = getpass.getpass("Powtorz haslo: ")
+        if not password:
+            print("Haslo nie moze byc puste.")
+            continue
+        if password != confirm:
+            print("Hasla nie sa identyczne. Sprobuj ponownie.")
+            continue
+        break
+
+    data = {
+        "business": business,
+        "password_hash": hash_password(password),
+        "invoices": [],
+    }
+    save_data(data)
+    print("\nDane zapisane. Uruchom aplikacje ponownie, aby zalogowac sie i wystawiac faktury.")
+
+
+def authenticate(data) -> bool:
+    for attempt in range(3):
+        password = getpass.getpass("Haslo: ")
+        if hash_password(password) == data["password_hash"]:
+            return True
+        print("Nieprawidlowe haslo.")
+    return False
+
+
+def prompt_client_details():
+    answer = input("Dodac dane klienta? (T/N): ").strip().lower()
+    if answer not in ("t", "tak"):
+        return {}
+    print("\n=== Dane klienta ===")
+    client = {
+        "name": prompt_non_empty("Nazwa / Imie i nazwisko: "),
+        "address": prompt_non_empty("Adres: "),
+        "tax_id": input("NIP (opcjonalnie): ").strip(),
+    }
+    return client
+
+
+def format_invoice_text(invoice_id: str, business: dict, invoice: dict) -> str:
+    lines = [
+        f"Faktura: {invoice_id}",
+        f"Data wystawienia: {invoice['issued_at']}",
+        "",
+        "=== Sprzedawca ===",
+        f"Nazwa: {business['company_name']}",
+        f"Wlasciciel: {business['owner_name']}",
+        f"Adres: {business['address']}",
+        f"NIP: {business['tax_id']}",
+        f"Konto bankowe: {business['bank_account']}",
+        "",
+        "=== Nabywca ===",
+    ]
+
+    client = invoice.get("client", {})
+    if client:
+        lines.extend(
+            [
+                f"Nazwa: {client.get('name', '')}",
+                f"Adres: {client.get('address', '')}",
+                f"NIP: {client.get('tax_id', '') or '---'}",
+            ]
+        )
+    else:
+        lines.append("Brak danych klienta (pole opcjonalne).")
+
+    lines.extend(
+        [
+            "",
+            "=== Pozycja ===",
+            f"Opis: {invoice['item_description']}",
+            f"Ilosc: {invoice['quantity']}",
+            f"Cena jednostkowa: {invoice['unit_price']:.2f} PLN",
+            f"Wartosc netto: {invoice['net_total']:.2f} PLN",
+        ]
+    )
+    return "\n".join(lines)
+
+
+def create_invoice(data):
+    print("\n=== Wystaw fakture ===")
+    description = prompt_non_empty("Opis uslugi / towaru: ")
+    quantity = prompt_positive_float("Ilosc: ")
+    unit_price = prompt_positive_float("Cena jednostkowa (PLN): ")
+    client = prompt_client_details()
+
+    issued_at = datetime.now().strftime("%Y-%m-%d %H:%M")
+    invoice_id = datetime.now().strftime("FV-%Y%m%d-%H%M%S")
+    net_total = quantity * unit_price
+
+    invoice = {
+        "invoice_id": invoice_id,
+        "issued_at": issued_at,
+        "item_description": description,
+        "quantity": quantity,
+        "unit_price": unit_price,
+        "net_total": net_total,
+        "client": client,
+    }
+
+    os.makedirs(INVOICE_FOLDER, exist_ok=True)
+    invoice_path = os.path.join(INVOICE_FOLDER, f"{invoice_id}.txt")
+    with open(invoice_path, "w", encoding="utf-8") as handle:
+        handle.write(format_invoice_text(invoice_id, data["business"], invoice))
+
+    data["invoices"].append(invoice)
+    save_data(data)
+
+    print(f"\nFaktura zapisana do {invoice_path}")
+    print(f"Suma do zaplaty: {net_total:.2f} PLN")
+
+
+def main():
+    data = load_data()
+    if data is None:
+        run_setup()
+        return
+
+    print("=== Logowanie ===")
+    if not authenticate(data):
+        print("Zbyt wiele nieudanych prob logowania. Zakonczono.")
+        return
+
+    create_invoice(data)
+
+
+if __name__ == "__main__":
+    main()

main.js

@@ -1,2326 +0,0 @@
-const APP_PATHNAME =
-  typeof window !== "undefined" && window.location && typeof window.location.pathname === "string"
-    ? window.location.pathname.replace(/\/$/, "")
-    : "";
-
-const VAT_OPTIONS = [
-  { value: "23", label: "23%" },
-  { value: "8", label: "8%" },
-  { value: "5", label: "5%" },
-  { value: "0", label: "0% (ZW)" },
-  { value: "ZW", label: "ZW - zwolnione" },
-  { value: "NP", label: "NP - poza zakresem" },
-];
-
-const VAT_RATE_VALUES = {
-  "23": 0.23,
-  "8": 0.08,
-  "5": 0.05,
-  "0": 0,
-  ZW: 0,
-  NP: 0,
-};
-
-const UNIT_OPTIONS = [
-  { value: "szt.", label: "szt." },
-  { value: "godz.", label: "godz." },
-];
-
-const DEFAULT_UNIT = UNIT_OPTIONS[0].value;
-
-const EXEMPTION_REASONS = [
-  {
-    value: "art_43_1_19",
-    label: "Art. 43 ust. 1 pkt 19 ustawy o VAT - usługi medyczne",
-    note: "Art. 43 ust. 1 pkt 19 ustawy o VAT - usługi w zakresie opieki medycznej.",
-  },
-  {
-    value: "art_43_1_18",
-    label: "Art. 43 ust. 1 pkt 18 ustawy o VAT - usługi edukacyjne",
-    note: "Art. 43 ust. 1 pkt 18 ustawy o VAT - usługi edukacyjne w formach przewidzianych w przepisach.",
-  },
-  {
-    value: "art_43_1_37",
-    label: "Art. 43 ust. 1 pkt 37 ustawy o VAT - usługi finansowe",
-    note: "Art. 43 ust. 1 pkt 37 ustawy o VAT - usługi finansowe i pośrednictwa finansowego.",
-  },
-  {
-    value: "art_113",
-    label: "Art. 113 ust. 1 i 9 ustawy o VAT - zwolnienie podmiotowe",
-    note: "Art. 113 ust. 1 i 9 ustawy o VAT - zwolnienie podmiotowe do 200 000 PLN obrotu.",
-  },
-  {
-    value: "par_3_ust_1_pkt_1",
-    label: "Par. 3 ust. 1 pkt 1 rozporządzenia MF z 20.12.2013 r.",
-    note: "Par. 3 ust. 1 pkt 1 rozporządzenia MF z 20.12.2013 r. - dostawa towarów używanych.",
-  },
-  {
-    value: "custom",
-    label: "Inne (wpisz własny opis)",
-    note: "",
-  },
-];
-
-const EXEMPTION_REASON_LOOKUP = new Map(EXEMPTION_REASONS.map((reason) => [reason.value, reason]));
-
-const heroPanel = document.getElementById("hero-panel");
-const authSection = document.getElementById("auth-section");
-const appSection = document.getElementById("app-section");
-
-const registerForm = document.getElementById("register-form");
-const loginForm = document.getElementById("login-form");
-const loginSubmitButton = loginForm ? loginForm.querySelector('button[type="submit"]') : null;
-const loginSubmitButtonDefaultText = loginSubmitButton && loginSubmitButton.textContent ? loginSubmitButton.textContent.trim() || "Zaloguj" : "Zaloguj";
-const invoiceForm = document.getElementById("invoice-form");
-const businessForm = document.getElementById("business-form");
-
-const registerFeedback = document.getElementById("register-feedback");
-const loginFeedback = document.getElementById("login-feedback");
-const businessFeedback = document.getElementById("business-feedback");
-const logoFeedback = document.getElementById("logo-feedback");
-const registerSection = document.getElementById("register-section");
-const showRegisterButton = document.getElementById("show-register-button");
-const backToLoginButton = document.getElementById("back-to-login");
-const cancelRegisterButton = document.getElementById("cancel-register");
-const clientSearchInput = document.getElementById("client-search");
-const clientSuggestionsContainer = document.getElementById("client-suggestions");
-const loginBadge = document.getElementById("login-badge");
-
-const businessDisplay = document.getElementById("business-display");
-const toggleBusinessFormButton = document.getElementById("toggle-business-form");
-const cancelBusinessUpdateButton = document.getElementById("cancel-business-update");
-const currentLoginLabel = document.getElementById("current-login-label");
-
-const itemsBody = document.getElementById("items-body");
-const addItemButton = document.getElementById("add-item-button");
-
-const totalNetLabel = document.getElementById("total-net");
-const totalVatLabel = document.getElementById("total-vat");
-const totalGrossLabel = document.getElementById("total-gross");
-const rateSummaryContainer = document.getElementById("rate-summary");
-
-const exemptionNoteWrapper = document.getElementById("exemption-note-wrapper");
-const exemptionReasonSelect = document.getElementById("exemption-reason");
-const exemptionNoteInput = document.getElementById("exemption-note");
-
-const invoiceResult = document.getElementById("invoice-result");
-const invoiceOutput = document.getElementById("invoice-output");
-const downloadButton = document.getElementById("download-button");
-const logoutButton = document.getElementById("logout-button");
-const cancelEditInvoiceButton = document.getElementById("cancel-edit-invoice");
-const saveInvoiceButton = document.getElementById("save-invoice-button");
-
-const invoiceBuilderSection = document.getElementById("invoice-builder-section");
-const dashboardSection = document.getElementById("dashboard-section");
-const appNavButtons = Array.from(document.querySelectorAll(".app-nav-button"));
-
-const invoicesTableBody = document.getElementById("invoices-table-body");
-const invoicesEmpty = document.getElementById("invoices-empty");
-const dashboardFeedback = document.getElementById("dashboard-feedback");
-
-const filterStartDate = document.getElementById("filter-start-date");
-const filterEndDate = document.getElementById("filter-end-date");
-const clearFiltersButton = document.getElementById("clear-filters");
-
-const summaryMonthCount = document.getElementById("summary-month-count");
-const summaryMonthAmount = document.getElementById("summary-month-amount");
-const summaryQuarterCount = document.getElementById("summary-quarter-count");
-const summaryQuarterAmount = document.getElementById("summary-quarter-amount");
-const summaryYearCount = document.getElementById("summary-year-count");
-const summaryYearAmount = document.getElementById("summary-year-amount");
-
-const logoInput = document.getElementById("logo-input");
-const logoPreview = document.getElementById("logo-preview");
-const logoPreviewImage = document.getElementById("logo-preview-image");
-const removeLogoButton = document.getElementById("remove-logo-button");
-const legacyLoginHint = document.getElementById("legacy-login-hint");
-const invoicesChartCanvas = document.getElementById("invoices-chart");
-
-let authToken = sessionStorage.getItem("invoiceAuthToken") || null;
-let currentLogin = sessionStorage.getItem("invoiceLogin") || "";
-let currentBusiness = null;
-let currentLogo = null;
-let lastInvoice = null;
-let invoicesCache = [];
-let editingInvoiceId = null;
-let activeView = "invoice-builder";
-let invoicesChart = null;
-let maxLogoSize = 512 * 1024;
-let pdfFontPromise = null;
-let pdfFontBase64 = null;
-let customExemptionNote = "";
-let clientLookupTimeout = null;
-
-function setVisibility(element, visible) {
-  if (!element) {
-    return;
-  }
-  if (visible) {
-    element.classList.remove("hidden");
-    element.style.removeProperty("display");
-  } else {
-    element.classList.add("hidden");
-    element.style.display = "none";
-  }
-}
-
-function setAppState(state) {
-  if (state === "app") {
-    setVisibility(authSection, false);
-    setVisibility(registerSection, false);
-    setVisibility(appSection, true);
-    setVisibility(heroPanel, false);
-  } else {
-    setVisibility(authSection, true);
-    setVisibility(registerSection, false);
-    setVisibility(appSection, false);
-    setVisibility(heroPanel, true);
-  }
-}
-
-function openRegisterPanel() {
-  if (!registerSection) {
-    return;
-  }
-  setVisibility(authSection, false);
-  setVisibility(registerSection, true);
-  setVisibility(appSection, false);
-  clearFeedback(registerFeedback);
-  clearFeedback(loginFeedback);
-  if (registerForm) {
-    const emailInput = registerForm.elements.email;
-    if (emailInput) {
-      emailInput.focus();
-    }
-  }
-  const scrollTarget = registerSection.querySelector(".register-card") || registerSection;
-  const scrollIntoView = () => scrollTarget.scrollIntoView({ behavior: "smooth", block: "start" });
-  if (typeof window !== "undefined" && typeof window.requestAnimationFrame === "function") {
-    window.requestAnimationFrame(scrollIntoView);
-  } else if (typeof requestAnimationFrame === "function") {
-    requestAnimationFrame(scrollIntoView);
-  } else {
-    scrollIntoView();
-  }
-}
-
-function closeRegisterPanel({ resetForm = true, focusTrigger = false } = {}) {
-  if (!registerSection) {
-    return;
-  }
-  setVisibility(registerSection, false);
-  setVisibility(authSection, true);
-  setVisibility(appSection, false);
-  clearFeedback(registerFeedback);
-  clearFeedback(loginFeedback);
-  if (resetForm && registerForm) {
-    registerForm.reset();
-  }
-  if (focusTrigger) {
-    if (showRegisterButton) {
-      showRegisterButton.focus();
-    }
-    const scrollTarget = authSection ? authSection.querySelector(".login-card") || authSection : null;
-    if (scrollTarget) {
-      const scrollToLogin = () => scrollTarget.scrollIntoView({ behavior: "smooth", block: "start" });
-      if (typeof window !== "undefined" && typeof window.requestAnimationFrame === "function") {
-        window.requestAnimationFrame(scrollToLogin);
-      } else if (typeof requestAnimationFrame === "function") {
-        requestAnimationFrame(scrollToLogin);
-      } else {
-        scrollToLogin();
-      }
-    }
-  }
-}
-
-function clearFeedback(element) {
-  if (!element) {
-    return;
-  }
-  element.textContent = "";
-  element.classList.remove("error", "success");
-}
-
-function showFeedback(element, message, type = "error") {
-  if (!element) {
-    return;
-  }
-  element.textContent = message;
-  element.classList.remove("error", "success");
-  if (type) {
-    element.classList.add(type);
-  }
-}
-
-function parseNumber(value) {
-  if (typeof value === "number") {
-    return Number.isFinite(value) ? value : 0;
-  }
-  if (!value) {
-    return 0;
-  }
-  const normalized = value.toString().replace(",", ".");
-  const parsed = Number.parseFloat(normalized);
-  return Number.isFinite(parsed) ? parsed : 0;
-}
-
-function parseIntegerString(value) {
-  if (value === null || value === undefined) {
-    return Number.NaN;
-  }
-  const normalized = value.toString().trim();
-  if (!normalized) {
-    return 0;
-  }
-  const parsed = Number.parseFloat(normalized.replace(",", "."));
-  if (!Number.isFinite(parsed) || Math.floor(parsed) !== parsed) {
-    return Number.NaN;
-  }
-  return parsed;
-}
-
-function formatQuantity(value) {
-  const parsed = parseIntegerString(value);
-  if (Number.isNaN(parsed)) {
-    return "0";
-  }
-  return parsed.toString();
-}
-
-function formatCurrency(value) {
-  const number = parseNumber(value);
-  return `${number.toFixed(2)} PLN`;
-}
-
-function vatLabelFromCode(code) {
-  if (code === "ZW" || code === "0") {
-    return "ZW";
-  }
-  if (code === "NP") {
-    return "NP";
-  }
-  return `${code}%`;
-}
-
-function requiresExemption(code) {
-  return code === "ZW" || code === "0";
-}
-
-function populateExemptionReasons() {
-  if (!exemptionReasonSelect || exemptionReasonSelect.dataset.initialized === "true") {
-    return;
-  }
-  const existingValues = new Set(Array.from(exemptionReasonSelect.options).map((option) => option.value));
-  EXEMPTION_REASONS.forEach((reason) => {
-    if (existingValues.has(reason.value)) {
-      return;
-    }
-    const option = document.createElement("option");
-    option.value = reason.value;
-    option.textContent = reason.label;
-    exemptionReasonSelect.appendChild(option);
-  });
-  exemptionReasonSelect.dataset.initialized = "true";
-}
-
-function applyExemptionReasonSelection({ preserveCustom = false } = {}) {
-  if (!exemptionReasonSelect || !exemptionNoteInput) {
-    return;
-  }
-  const selectedValue = exemptionReasonSelect.value;
-  const selectedReason = EXEMPTION_REASON_LOOKUP.get(selectedValue);
-  
-  // Ukryj pole "Podstawa prawna zwolnienia" jeśli nie wybrano opcji "Inne..."
-  const exemptionNoteLabel = document.getElementById("exemption-note-label");
-  if (exemptionNoteLabel) {
-    if (selectedValue === "custom") {
-      exemptionNoteLabel.style.display = "block";
-      exemptionNoteInput.style.display = "block";
-    } else {
-      exemptionNoteLabel.style.display = "none";
-      exemptionNoteInput.style.display = "none";
-    }
-  }
-  
-  if (!selectedReason) {
-    if (!preserveCustom) {
-      exemptionNoteInput.readOnly = false;
-      exemptionNoteInput.value = "";
-    }
-    return;
-  }
-  if (selectedValue === "custom") {
-    exemptionNoteInput.readOnly = false;
-    if (!preserveCustom) {
-      exemptionNoteInput.value = customExemptionNote;
-    }
-    return;
-  }
-  exemptionNoteInput.readOnly = true;
-  exemptionNoteInput.value = selectedReason.note;
-}
-
-function findExemptionReasonByNote(note) {
-  if (!note) {
-    return null;
-  }
-  const normalized = note.trim().toLowerCase();
-  return (
-    EXEMPTION_REASONS.find(
-      (reason) =>
-        reason.value !== "custom" && reason.note && reason.note.trim().toLowerCase() === normalized
-    ) || null
-  );
-}
-
-function syncExemptionControlsWithNote(note) {
-  if (!exemptionNoteInput) {
-    return;
-  }
-  const trimmed = (note || "").trim();
-  exemptionNoteInput.readOnly = false;
-  if (!exemptionReasonSelect) {
-    exemptionNoteInput.value = trimmed;
-    return;
-  }
-  if (!trimmed) {
-    customExemptionNote = "";
-    exemptionReasonSelect.value = "";
-    exemptionNoteInput.value = "";
-    return;
-  }
-  const matchedReason = findExemptionReasonByNote(trimmed);
-  if (matchedReason && matchedReason.value !== "custom") {
-    exemptionReasonSelect.value = matchedReason.value;
-    applyExemptionReasonSelection({ preserveCustom: true });
-  } else {
-    customExemptionNote = trimmed;
-    exemptionReasonSelect.value = "custom";
-    exemptionNoteInput.readOnly = false;
-    exemptionNoteInput.value = trimmed;
-  }
-}
-
-function updateExemptionVisibility(exemptionNeeded) {
-  if (!exemptionNoteWrapper || !exemptionNoteInput) {
-    return;
-  }
-  if (exemptionNeeded) {
-    populateExemptionReasons();
-    setVisibility(exemptionNoteWrapper, true);
-    applyExemptionReasonSelection({ preserveCustom: true });
-    return;
-  }
-  setVisibility(exemptionNoteWrapper, false);
-  if (exemptionReasonSelect) {
-    exemptionReasonSelect.value = "";
-  }
-  customExemptionNote = "";
-  exemptionNoteInput.readOnly = false;
-  exemptionNoteInput.value = "";
-}
-
-function formatInvoicesCount(count) {
-  const value = Number.parseInt(count, 10) || 0;
-  const absolute = Math.abs(value);
-  const mod10 = absolute % 10;
-  const mod100 = absolute % 100;
-  let suffix = "faktur";
-  if (mod10 === 1 && mod100 !== 11) {
-    suffix = "faktura";
-  } else if ([2, 3, 4].includes(mod10) && ![12, 13, 14].includes(mod100)) {
-    suffix = "faktury";
-  }
-  return `${value} ${suffix}`;
-}
-
-function parseInvoiceIssuedAt(invoice) {
-  if (!invoice || !invoice.issued_at) {
-    return null;
-  }
-  const normalized = invoice.issued_at.replace(" ", "T");
-  const parsed = new Date(normalized);
-  return Number.isNaN(parsed.getTime()) ? null : parsed;
-}
-
-function parseDateInput(value) {
-  if (!value) {
-    return null;
-  }
-  const parts = value.split("-").map((part) => Number.parseInt(part, 10));
-  if (parts.length !== 3 || parts.some(Number.isNaN)) {
-    return null;
-  }
-  return new Date(parts[0], parts[1] - 1, parts[2]);
-}
-
-function setActiveView(view) {
-  activeView = view === "dashboard" ? "dashboard" : "invoice-builder";
-  setVisibility(invoiceBuilderSection, activeView === "invoice-builder");
-  setVisibility(dashboardSection, activeView === "dashboard");
-  const showDashboard = activeView === "dashboard";
-  appNavButtons.forEach((button) => {
-    button.classList.toggle("active", button.dataset.view === activeView);
-  });
-  if (showDashboard) {
-    applyInvoiceFilters();
-  }
-}
-
-function updateLoginLabel() {
-  if (!currentLoginLabel) {
-    return;
-  }
-  if (!currentLogin) {
-    currentLoginLabel.textContent = "";
-    if (loginBadge) {
-      loginBadge.classList.add("hidden");
-    }
-    return;
-  }
-  currentLoginLabel.textContent = currentLogin;
-  if (loginBadge) {
-    loginBadge.classList.remove("hidden");
-  }
-}
-
-function updateLogoPreview() {
-  if (currentLogo && currentLogo.data && currentLogo.mime_type) {
-    const dataUrl = currentLogo.data_url || `data:${currentLogo.mime_type};base64,${currentLogo.data}`;
-    logoPreviewImage.src = dataUrl;
-    logoPreview.classList.remove("hidden");
-    removeLogoButton.classList.remove("hidden");
-  } else {
-    logoPreviewImage.removeAttribute("src");
-    logoPreview.classList.add("hidden");
-    removeLogoButton.classList.add("hidden");
-  }
-}
-
-function renderInvoicesTable(invoices) {
-  invoicesTableBody.innerHTML = "";
-  if (!Array.isArray(invoices) || invoices.length === 0) {
-    invoicesEmpty.classList.remove("hidden");
-    return;
-  }
-
-  invoicesEmpty.classList.add("hidden");
-  invoices.forEach((invoice) => {
-    const row = document.createElement("tr");
-
-    const numberCell = document.createElement("td");
-    numberCell.textContent = invoice.invoice_id || "---";
-    row.appendChild(numberCell);
-
-    const issuedCell = document.createElement("td");
-    issuedCell.textContent = invoice.issued_at || "-";
-    row.appendChild(issuedCell);
-
-    const clientCell = document.createElement("td");
-    const clientName = invoice.client?.name || "";
-    const clientCity = invoice.client?.city || "";
-    clientCell.textContent = clientName ? `${clientName}${clientCity ? ` (${clientCity})` : ""}` : "-";
-    row.appendChild(clientCell);
-
-    const grossCell = document.createElement("td");
-    grossCell.textContent = formatCurrency(invoice.totals?.gross ?? 0);
-    row.appendChild(grossCell);
-
-    const actionsCell = document.createElement("td");
-    const actionsWrapper = document.createElement("div");
-    actionsWrapper.className = "table-actions";
-
-    const editButton = document.createElement("button");
-    editButton.type = "button";
-    editButton.textContent = "Edytuj";
-    editButton.addEventListener("click", () => {
-      startInvoiceEdit(invoice.invoice_id);
-    });
-
-    const pdfButton = document.createElement("button");
-    pdfButton.type = "button";
-    pdfButton.className = "button secondary";
-    pdfButton.dataset.download = invoice.invoice_id;
-    pdfButton.textContent = "PDF";
-
-    const deleteButton = document.createElement("button");
-    deleteButton.type = "button";
-    deleteButton.className = "button secondary";
-    deleteButton.textContent = "Usuń";
-    deleteButton.addEventListener("click", async () => {
-      clearFeedback(dashboardFeedback);
-      const shouldDelete = window.confirm(`Usuńac fakturę ${invoice.invoice_id}?`);
-      if (!shouldDelete) {
-        return;
-      }
-      await deleteInvoice(invoice.invoice_id);
-    });
-
-    actionsWrapper.appendChild(editButton);
-    actionsWrapper.appendChild(pdfButton);
-    actionsWrapper.appendChild(deleteButton);
-    actionsCell.appendChild(actionsWrapper);
-    row.appendChild(actionsCell);
-
-    invoicesTableBody.appendChild(row);
-  });
-}
-
-function applyInvoiceFilters() {
-  if (!Array.isArray(invoicesCache)) {
-    renderInvoicesTable([]);
-    return;
-  }
-
-  let filtered = invoicesCache.slice();
-  const startDate = parseDateInput(filterStartDate?.value);
-  const endDate = parseDateInput(filterEndDate?.value);
-
-  if (startDate) {
-    const startTime = startDate.getTime();
-    filtered = filtered.filter((invoice) => {
-      const issued = parseInvoiceIssuedAt(invoice);
-      return !issued || issued.getTime() >= startTime;
-    });
-  }
-
-  if (endDate) {
-    const endBoundary = new Date(endDate);
-    endBoundary.setHours(23, 59, 59, 999);
-    const endTime = endBoundary.getTime();
-    filtered = filtered.filter((invoice) => {
-      const issued = parseInvoiceIssuedAt(invoice);
-      return !issued || issued.getTime() <= endTime;
-    });
-  }
-
-  filtered.sort((a, b) => (b.issued_at || "").localeCompare(a.issued_at || ""));
-  renderInvoicesTable(filtered);
-}
-
-if (invoicesTableBody) {
-  invoicesTableBody.addEventListener("click", async (event) => {
-    const target = event.target;
-    if (!(target instanceof HTMLElement)) {
-      return;
-    }
-    const pdfTrigger = target.closest("[data-download]");
-    if (pdfTrigger) {
-      const invoiceId = pdfTrigger.getAttribute("data-download");
-      if (!invoiceId) {
-        return;
-      }
-      const invoiceData = invoicesCache.find((invoice) => invoice.invoice_id === invoiceId);
-      if (!invoiceData || !currentBusiness) {
-        showFeedback(dashboardFeedback, "Nie udało się przygotować PDF. Odśwież dane i spróbuj ponownie.");
-        return;
-      }
-      try {
-        await generatePdf(currentBusiness, invoiceData, currentLogo);
-      } catch (error) {
-        console.error(error);
-        showFeedback(dashboardFeedback, "Nie udało się wygenerować PDF-a.");
-      }
-    }
-  });
-}
-
-async function refreshInvoices() {
-  if (!authToken) {
-    invoicesCache = [];
-    renderInvoicesTable([]);
-    return;
-  }
-  clearFeedback(dashboardFeedback);
-  try {
-    const data = await apiRequest("/api/invoices", {}, true);
-    invoicesCache = Array.isArray(data.invoices) ? data.invoices.slice() : [];
-    invoicesCache.sort((a, b) => (b.issued_at || "").localeCompare(a.issued_at || ""));
-    applyInvoiceFilters();
-  } catch (error) {
-    console.error(error);
-    showFeedback(dashboardFeedback, error.message || "Nie udało się pobrać faktur.");
-  }
-}
-
-function updateSummaryCards(summary) {
-  const monthSummary = summary?.last_month || { count: 0, gross_total: 0 };
-  const quarterSummary = summary?.quarter || { count: 0, gross_total: 0 };
-  const yearSummary = summary?.year || { count: 0, gross_total: 0 };
-
-  summaryMonthCount.textContent = formatInvoicesCount(monthSummary.count);
-  summaryQuarterCount.textContent = formatInvoicesCount(quarterSummary.count);
-  summaryYearCount.textContent = formatInvoicesCount(yearSummary.count);
-
-  summaryMonthAmount.textContent = formatCurrency(monthSummary.gross_total ?? 0);
-  summaryQuarterAmount.textContent = formatCurrency(quarterSummary.gross_total ?? 0);
-  summaryYearAmount.textContent = formatCurrency(yearSummary.gross_total ?? 0);
-}
-
-function updateSummaryChart(summary) {
-  if (!invoicesChartCanvas || typeof window.Chart === "undefined") {
-    return;
-  }
-
-  const labels = ["Ostatnie 30 dni", "Bieżący kwartał", "Bieżący rok"];
-  const counts = [
-    Number.parseInt(summary?.last_month?.count ?? 0, 10) || 0,
-    Number.parseInt(summary?.quarter?.count ?? 0, 10) || 0,
-    Number.parseInt(summary?.year?.count ?? 0, 10) || 0,
-  ];
-  const amounts = [
-    parseNumber(summary?.last_month?.gross_total ?? 0),
-    parseNumber(summary?.quarter?.gross_total ?? 0),
-    parseNumber(summary?.year?.gross_total ?? 0),
-  ];
-
-  const chartData = {
-    labels,
-    datasets: [
-      {
-        label: "Liczba faktur",
-        data: counts,
-        backgroundColor: "rgba(26, 115, 232, 0.65)",
-        yAxisID: "count",
-        borderRadius: 6,
-      },
-      {
-        label: "Suma brutto (PLN)",
-        data: amounts,
-        type: "line",
-        fill: false,
-        borderColor: "rgba(26, 115, 232, 0.65)",
-        backgroundColor: "rgba(26, 115, 232, 0.35)",
-        tension: 0.3,
-        yAxisID: "amount",
-      },
-    ],
-  };
-
-  const options = {
-    responsive: true,
-    maintainAspectRatio: false,
-    scales: {
-      count: {
-        beginAtZero: true,
-        position: "left",
-        ticks: {
-          precision: 0,
-          stepSize: 1,
-        },
-      },
-      amount: {
-        beginAtZero: true,
-        position: "right",
-        grid: {
-          drawOnChartArea: false,
-        },
-        ticks: {
-          callback: (value) => `${new Intl.NumberFormat("pl-PL", { minimumFractionDigits: 2, maximumFractionDigits: 2 }).format(value)} PLN`,
-        },
-      },
-    },
-    plugins: {
-      legend: {
-        position: "bottom",
-      },
-      tooltip: {
-        callbacks: {
-          label(context) {
-            if (context.dataset.yAxisID === "amount") {
-              return `${context.dataset.label}: ${new Intl.NumberFormat("pl-PL", { minimumFractionDigits: 2, maximumFractionDigits: 2 }).format(context.parsed.y)} PLN`;
-            }
-            return `${context.dataset.label}: ${context.parsed.y}`;
-          },
-        },
-      },
-    },
-  };
-
-  if (!invoicesChart) {
-    invoicesChart = new window.Chart(invoicesChartCanvas, {
-      type: "bar",
-      data: chartData,
-      options,
-    });
-  } else {
-    invoicesChart.data = chartData;
-    invoicesChart.options = options;
-    invoicesChart.update();
-  }
-}
-
-async function refreshSummary() {
-  if (!authToken) {
-    updateSummaryCards({});
-    updateSummaryChart({});
-    return;
-  }
-  clearFeedback(dashboardFeedback);
-  try {
-    const data = await apiRequest("/api/invoices/summary", {}, true);
-    updateSummaryCards(data.summary);
-    updateSummaryChart(data.summary);
-  } catch (error) {
-    console.error(error);
-    showFeedback(dashboardFeedback, error.message || "Nie udało się pobrać podsumowania.");
-  }
-}
-
-async function deleteInvoice(invoiceId) {
-  if (!invoiceId) {
-    return;
-  }
-  try {
-    await apiRequest(`/api/invoices/${encodeURIComponent(invoiceId)}`, { method: "DELETE" }, true);
-    invoicesCache = invoicesCache.filter((invoice) => invoice.invoice_id !== invoiceId);
-    applyInvoiceFilters();
-    await refreshSummary();
-  } catch (error) {
-    console.error(error);
-    showFeedback(dashboardFeedback, error.message || "Nie udało się usunąć faktury.");
-  }
-}
-
-function startInvoiceEdit(invoiceId) {
-  if (!invoiceId) {
-    return;
-  }
-  const invoice = invoicesCache.find((item) => item.invoice_id === invoiceId);
-  if (!invoice) {
-    showFeedback(dashboardFeedback, "Nie znaleziono wybranej faktury.");
-    return;
-  }
-
-  editingInvoiceId = invoiceId;
-  saveInvoiceButton.textContent = "Zapisz zmiany";
-  cancelEditInvoiceButton.classList.remove("hidden");
-  setActiveView("invoice-builder");
-
-  resetInvoiceForm();
-  invoiceForm.elements.saleDate.value = invoice.sale_date || "";
-  invoiceForm.elements.paymentTerm.value = invoice.payment_term || 14;
-
-  if (invoice.client) {
-    setClientFormValues(invoice.client);
-  }
-
-  itemsBody.innerHTML = "";
-  if (Array.isArray(invoice.items) && invoice.items.length > 0) {
-    invoice.items.forEach((item) => {
-      createItemRow({
-        name: item.name,
-        quantity: item.quantity,
-        unit_price_gross: item.unit_price_gross ?? item.gross_total,
-        vat_code: item.vat_code,
-        unit: item.unit,
-      });
-    });
-  } else {
-    createItemRow();
-  }
-
-  const note = invoice.exemption_note || "";
-  syncExemptionControlsWithNote(note);
-  const requiresNote = Array.isArray(invoice.items)
-    ? invoice.items.some((item) => requiresExemption(item.vat_code))
-    : false;
-  updateExemptionVisibility(requiresNote);
-
-  lastInvoice = invoice;
-}
-
-function exitInvoiceEdit() {
-  editingInvoiceId = null;
-  saveInvoiceButton.textContent = "Generuj fakturę";
-  cancelEditInvoiceButton.classList.add("hidden");
-}
-
-function buildApiUrl(path = "") {
-  if (!path) {
-    return APP_PATHNAME || "/";
-  }
-  if (/^https?:\/\//i.test(path)) {
-    return path;
-  }
-  return path.startsWith("/")
-    ? `${APP_PATHNAME}${path}` || "/"
-    : `${APP_PATHNAME}/${path}`.replace(/\/{2,}/g, "/");
-}
-
-async function apiRequest(path, { method = "GET", body, headers = {} } = {}, requireAuth = false) {
-  const options = {
-    method,
-    headers: {
-      "Content-Type": "application/json",
-      ...headers,
-    },
-  };
-
-  if (body !== undefined) {
-    options.body = JSON.stringify(body);
-  }
-
-  if (requireAuth) {
-    if (!authToken) {
-      throw new Error("Brak tokenu autoryzacyjnego.");
-    }
-    options.headers.Authorization = `Bearer ${authToken}`;
-  }
-
-  const url = buildApiUrl(path);
-  const response = await fetch(url, options);
-  const isJson = response.headers.get("content-type")?.includes("application/json");
-  const data = isJson ? await response.json() : {};
-
-  if (response.status === 401) {
-    authToken = null;
-    currentLogin = "";
-    sessionStorage.removeItem("invoiceAuthToken");
-    sessionStorage.removeItem("invoiceLogin");
-    setAppState("auth");
-    throw new Error(data.error || "Sesja wygasła. Zaloguj się ponownie.");
-  }
-
-  if (!response.ok) {
-    throw new Error(data.error || "Wystapil błąd podczas komunikacji z serwerem.");
-  }
-
-  return data;
-}
-
-function renderBusinessDisplay(business) {
-  if (!business) {
-    businessDisplay.textContent = "Brak zapisanych danych firmy.";
-    return;
-  }
-
-  const fallback = (value) => {
-    if (!value) {
-      return "---";
-    }
-    const trimmed = value.toString().trim();
-    return trimmed || "---";
-  };
-
-  const companyName = fallback(business.company_name);
-  const ownerName = fallback(business.owner_name);
-  const addressLine = fallback(business.address_line);
-  const location = fallback([business.postal_code, business.city].filter(Boolean).join(" "));
-  const taxLine = `NIP: ${fallback(business.tax_id)}`;
-  const bankLine = `Konto: ${fallback(business.bank_account)}`;
-
-  businessDisplay.innerHTML = `
-    <div class="business-display-grid">
-      <div class="business-display-item business-display-item--name">
-        <strong>${companyName}</strong>
-        <span>${ownerName}</span>
-      </div>
-      <div class="business-display-item">
-        <span>${addressLine}</span>
-        <span>${location}</span>
-      </div>
-      <div class="business-display-item">
-        <span>${taxLine}</span>
-        <span>${bankLine}</span>
-      </div>
-    </div>
-  `;
-}
-
-function fillBusinessForm(business) {
-  if (!business) {
-    return;
-  }
-  businessForm.elements.company_name.value = business.company_name || "";
-  businessForm.elements.owner_name.value = business.owner_name || "";
-  businessForm.elements.address_line.value = business.address_line || "";
-  businessForm.elements.postal_code.value = business.postal_code || "";
-  businessForm.elements.city.value = business.city || "";
-  businessForm.elements.tax_id.value = business.tax_id || "";
-  businessForm.elements.bank_account.value = business.bank_account || "";
-}
-
-function setBusinessFormVisibility(visible, { preserveFeedback = false } = {}) {
-  setVisibility(businessForm, visible);
-  if (toggleBusinessFormButton) {
-    toggleBusinessFormButton.textContent = visible ? "Ukryj formularz" : "Edycja danych";
-  }
-  if (!visible && !preserveFeedback) {
-    clearFeedback(businessFeedback);
-  }
-}
-
-function setClientFormValues(client = {}) {
-  if (!invoiceForm) {
-    return;
-  }
-  invoiceForm.elements.clientName.value = client.name || "";
-  invoiceForm.elements.clientTaxId.value = client.tax_id || "";
-  invoiceForm.elements.clientAddress.value = client.address_line || "";
-  invoiceForm.elements.clientPostalCode.value = client.postal_code || "";
-  invoiceForm.elements.clientCity.value = client.city || "";
-  invoiceForm.elements.clientPhone.value = client.phone || "";
-}
-
-function hideClientSuggestions() {
-  if (!clientSuggestionsContainer) {
-    return;
-  }
-  clientSuggestionsContainer.classList.add("hidden");
-  clientSuggestionsContainer.innerHTML = "";
-}
-
-function selectClientFromLookup(client) {
-  setClientFormValues(client);
-  if (clientSearchInput) {
-    const summary = [client.name, client.tax_id].filter(Boolean).join(" • ");
-    clientSearchInput.value = summary || client.name || client.tax_id || "";
-  }
-  hideClientSuggestions();
-}
-
-function renderClientSuggestions(clients) {
-  if (!clientSuggestionsContainer) {
-    return;
-  }
-  clientSuggestionsContainer.innerHTML = "";
-  if (!Array.isArray(clients) || clients.length === 0) {
-    const empty = document.createElement("p");
-    empty.className = "client-suggestions-empty";
-    empty.textContent = "Brak dopasowanych klientów.";
-    clientSuggestionsContainer.appendChild(empty);
-    clientSuggestionsContainer.classList.remove("hidden");
-    return;
-  }
-  const fragment = document.createDocumentFragment();
-  clients.forEach((client) => {
-    const button = document.createElement("button");
-    button.type = "button";
-    button.className = "client-suggestion";
-    button.setAttribute("role", "option");
-    button.innerHTML = `
-      <strong>${client.name || "Bez nazwy"}</strong>
-      <span>${[client.tax_id, client.city].filter(Boolean).join(" • ")}</span>
-    `;
-    button.addEventListener("click", () => {
-      selectClientFromLookup(client);
-    });
-    fragment.appendChild(button);
-  });
-  clientSuggestionsContainer.appendChild(fragment);
-  clientSuggestionsContainer.classList.remove("hidden");
-}
-
-async function requestClientSuggestions(term) {
-  const query = (term || "").trim();
-  if (!clientSuggestionsContainer || !clientSearchInput) {
-    return;
-  }
-  if (!authToken || query.length < 2) {
-    hideClientSuggestions();
-    return;
-  }
-  try {
-    const data = await apiRequest(`/api/clients?q=${encodeURIComponent(query)}`, {}, true);
-    renderClientSuggestions(data.clients || []);
-  } catch (error) {
-    console.error(error);
-    hideClientSuggestions();
-  }
-}
-
-function handleClientSearchInput(event) {
-  const term = event.target.value || "";
-  if (clientLookupTimeout) {
-    window.clearTimeout(clientLookupTimeout);
-  }
-  if (!term.trim()) {
-    hideClientSuggestions();
-    return;
-  }
-  clientLookupTimeout = window.setTimeout(() => {
-    requestClientSuggestions(term);
-  }, 250);
-}
-
-function vatSelectElement(initialValue = "23") {
-  const select = document.createElement("select");
-  select.className = "item-vat";
-  VAT_OPTIONS.forEach((option) => {
-    const element = document.createElement("option");
-    element.value = option.value;
-    element.textContent = option.label;
-    select.appendChild(element);
-  });
-  select.value = VAT_OPTIONS.some((option) => option.value === initialValue) ? initialValue : "23";
-  return select;
-}
-
-function unitSelectElement(initialValue = DEFAULT_UNIT) {
-  const select = document.createElement("select");
-  select.className = "item-unit";
-  UNIT_OPTIONS.forEach((option) => {
-    const element = document.createElement("option");
-    element.value = option.value;
-    element.textContent = option.label;
-    select.appendChild(element);
-  });
-  select.value = UNIT_OPTIONS.some((option) => option.value === initialValue) ? initialValue : DEFAULT_UNIT;
-  return select;
-}
-
-function createItemRow(initialValues = {}) {
-  const row = document.createElement("tr");
-
-  const nameCell = document.createElement("td");
-  const nameInput = document.createElement("input");
-  nameInput.type = "text";
-  nameInput.className = "item-name";
-  nameInput.placeholder = "Nazwa towaru lub usługi";
-  if (initialValues.name) {
-    nameInput.value = initialValues.name;
-  }
-  nameCell.appendChild(nameInput);
-
-  const quantityCell = document.createElement("td");
-  const quantityInput = document.createElement("input");
-  quantityInput.type = "number";
-  quantityInput.className = "item-quantity";
-  quantityInput.min = "1";
-  quantityInput.step = "1";
-  quantityInput.inputMode = "numeric";
-  const parsedQuantity = parseIntegerString(initialValues.quantity);
-  const safeQuantity = Number.isNaN(parsedQuantity) || parsedQuantity <= 0 ? 1 : parsedQuantity;
-  quantityInput.value = String(safeQuantity);
-  quantityCell.appendChild(quantityInput);
-
-  const unitCell = document.createElement("td");
-  const unitSelect = unitSelectElement(initialValues.unit);
-  unitCell.appendChild(unitSelect);
-
-  const unitGrossCell = document.createElement("td");
-  const unitGrossInput = document.createElement("input");
-  unitGrossInput.type = "number";
-  unitGrossInput.className = "item-gross";
-  unitGrossInput.min = "0.01";
-  unitGrossInput.step = "0.01";
-  unitGrossInput.placeholder = "Brutto";
-  if (initialValues.unit_price_gross) {
-    unitGrossInput.value = initialValues.unit_price_gross;
-  }
-  unitGrossCell.appendChild(unitGrossInput);
-
-  const vatCell = document.createElement("td");
-  const vatSelect = vatSelectElement(initialValues.vat_code);
-  vatCell.appendChild(vatSelect);
-
-  const totalCell = document.createElement("td");
-  totalCell.className = "item-total";
-  totalCell.textContent = "0.00 PLN";
-
-  const actionsCell = document.createElement("td");
-  const removeButton = document.createElement("button");
-  removeButton.type = "button";
-  removeButton.className = "remove-item";
-  removeButton.textContent = "Usuń";
-  actionsCell.appendChild(removeButton);
-
-  row.appendChild(nameCell);
-  row.appendChild(quantityCell);
-  row.appendChild(unitCell);
-  row.appendChild(unitGrossCell);
-  row.appendChild(vatCell);
-  row.appendChild(totalCell);
-  row.appendChild(actionsCell);
-
-  const handleChange = () => updateTotals();
-  nameInput.addEventListener("input", handleChange);
-  quantityInput.addEventListener("input", () => {
-    const sanitized = quantityInput.value.replace(/[^0-9]/g, "");
-    quantityInput.value = sanitized;
-    handleChange();
-  });
-  quantityInput.addEventListener("blur", () => {
-    const parsed = parseIntegerString(quantityInput.value);
-    quantityInput.value = Number.isNaN(parsed) || parsed <= 0 ? "1" : String(parsed);
-    handleChange();
-  });
-  unitGrossInput.addEventListener("input", handleChange);
-  vatSelect.addEventListener("change", handleChange);
-  unitSelect.addEventListener("change", handleChange);
-
-  removeButton.addEventListener("click", () => {
-    if (itemsBody.children.length === 1) {
-      nameInput.value = "";
-      quantityInput.value = "1";
-      unitGrossInput.value = "";
-      vatSelect.value = "23";
-      unitSelect.value = DEFAULT_UNIT;
-      updateTotals();
-      return;
-    }
-    row.remove();
-    updateTotals();
-  });
-
-  itemsBody.appendChild(row);
-  updateTotals();
-}
-
-function calculateRowTotals(row) {
-  const name = row.querySelector(".item-name")?.value.trim() ?? "";
-  const quantityRaw = row.querySelector(".item-quantity")?.value;
-  const quantityParsed = parseIntegerString(quantityRaw);
-  const quantityValid = Number.isInteger(quantityParsed) && quantityParsed > 0;
-  const quantity = quantityValid ? quantityParsed : 0;
-  const unitGross = parseNumber(row.querySelector(".item-gross")?.value);
-  const vatCode = row.querySelector(".item-vat")?.value ?? "23";
-  const rate = VAT_RATE_VALUES[vatCode] ?? 0;
-  const unit = row.querySelector(".item-unit")?.value || DEFAULT_UNIT;
-  const unitLabel = UNIT_OPTIONS.some((option) => option.value === unit) ? unit : DEFAULT_UNIT;
-
-  const hasValues = name || quantity > 0 || unitGross > 0;
-  if (!hasValues) {
-    return {
-      valid: false,
-      vatCode,
-      vatLabel: vatLabelFromCode(vatCode),
-      requiresExemption: requiresExemption(vatCode),
-      quantity,
-      unitGross,
-      unitNet: 0,
-      netTotal: 0,
-      vatAmount: 0,
-      grossTotal: 0,
-      unit: unitLabel,
-    };
-  }
-
-  if (!quantityValid || unitGross <= 0) {
-    return {
-      valid: false,
-      vatCode,
-      vatLabel: vatLabelFromCode(vatCode),
-      requiresExemption: requiresExemption(vatCode),
-      quantity,
-      unitGross,
-      unitNet: 0,
-      netTotal: 0,
-      vatAmount: 0,
-      grossTotal: quantity * unitGross,
-      unit: unitLabel,
-    };
-  }
-
-  const grossTotal = quantity * unitGross;
-  const netTotal = rate > 0 ? grossTotal / (1 + rate) : grossTotal;
-  const vatAmount = grossTotal - netTotal;
-  const unitNet = netTotal / quantity;
-
-  return {
-    valid: true,
-    vatCode,
-    vatLabel: vatLabelFromCode(vatCode),
-    requiresExemption: requiresExemption(vatCode),
-    quantity,
-    unitGross,
-    unitNet,
-    netTotal,
-    vatAmount,
-    grossTotal,
-    unit: unitLabel,
-  };
-}
-
-function updateTotals() {
-  let totalNet = 0;
-  let totalVat = 0;
-  let totalGross = 0;
-  const summary = new Map();
-  let exemptionNeeded = false;
-
-  const rows = Array.from(itemsBody.querySelectorAll("tr"));
-  rows.forEach((row) => {
-    const totals = calculateRowTotals(row);
-    if (totals.requiresExemption) {
-      exemptionNeeded = true;
-    }
-    const totalCell = row.querySelector(".item-total");
-    totalCell.textContent = formatCurrency(totals.grossTotal);
-
-    if (!totals.valid) {
-      return;
-    }
-
-    totalNet += totals.netTotal;
-    totalVat += totals.vatAmount;
-    totalGross += totals.grossTotal;
-
-    const existing = summary.get(totals.vatLabel) || { net: 0, vat: 0, gross: 0 };
-    existing.net += totals.netTotal;
-    existing.vat += totals.vatAmount;
-    existing.gross += totals.grossTotal;
-    summary.set(totals.vatLabel, existing);
-  });
-
-  totalNetLabel.textContent = `Suma netto: ${totalNet.toFixed(2)} PLN`;
-  totalVatLabel.textContent = `Kwota VAT: ${totalVat.toFixed(2)} PLN`;
-  totalGrossLabel.textContent = `Suma brutto: ${totalGross.toFixed(2)} PLN`;
-  renderRateSummary(summary);
-
-  updateExemptionVisibility(exemptionNeeded);
-}
-
-function renderRateSummary(summary) {
-  if (!summary || summary.size === 0) {
-    rateSummaryContainer.innerHTML = "";
-    return;
-  }
-
-  const entries = Array.from(summary.entries()).sort(([a], [b]) => a.localeCompare(b));
-  const markup = entries
-    .map(
-      ([label, totals]) =>
-        `<div class="rate-summary-item">
-          <span>${label}</span>
-          <span>Netto: ${totals.net.toFixed(2)} PLN</span>
-          <span>VAT: ${totals.vat.toFixed(2)} PLN</span>
-          <span>Brutto: ${totals.gross.toFixed(2)} PLN</span>
-        </div>`
-    )
-    .join("");
-  rateSummaryContainer.innerHTML = `<h4>Podsumowanie stawek</h4>${markup}`;
-}
-
-function collectInvoicePayload() {
-  const items = [];
-  const rows = Array.from(itemsBody.querySelectorAll("tr"));
-
-  rows.forEach((row) => {
-    const name = row.querySelector(".item-name")?.value.trim() ?? "";
-    const quantityRaw = row.querySelector(".item-quantity")?.value;
-    const quantityParsed = parseIntegerString(quantityRaw);
-    const quantityValid = Number.isInteger(quantityParsed) && quantityParsed > 0;
-    const quantity = quantityValid ? quantityParsed : 0;
-    const unitGross = parseNumber(row.querySelector(".item-gross")?.value);
-    const vatCode = row.querySelector(".item-vat")?.value ?? "23";
-    const unitValue = row.querySelector(".item-unit")?.value || DEFAULT_UNIT;
-    const unit = UNIT_OPTIONS.some((option) => option.value === unitValue) ? unitValue : DEFAULT_UNIT;
-
-    const hasValues = name || quantity > 0 || unitGross > 0;
-    if (!hasValues) {
-      return;
-    }
-
-    if (!name) {
-      throw new Error("Każda pozycja musi mieć nazwę.");
-    }
-    if (!quantityValid) {
-      throw new Error("Ilość musi byc dodatnia liczba calkowita.");
-    }
-    if (unitGross <= 0) {
-      throw new Error("Cena brutto musi być większa od zera.");
-    }
-
-    items.push({
-      name,
-      quantity,
-      unit,
-      unit_price_gross: unitGross.toFixed(2),
-      vat_code: vatCode,
-    });
-  });
-
-  if (items.length === 0) {
-    throw new Error("Dodaj przynajmniej jedną pozycję.");
-  }
-
-  const saleDate = invoiceForm.elements.saleDate.value || null;
-  const paymentTerm = parseInt(invoiceForm.elements.paymentTerm.value) || 14;
-  const requiresExemptionNote = items.some((item) => item.vat_code === "ZW" || item.vat_code === "0");
-  let exemptionNote = "";
-  if (requiresExemptionNote) {
-    const noteFromTextarea = exemptionNoteInput.value.trim();
-    if (exemptionReasonSelect) {
-      const selectedReason = EXEMPTION_REASON_LOOKUP.get(exemptionReasonSelect.value);
-      if (selectedReason && selectedReason.value !== "custom") {
-        exemptionNote = selectedReason.note;
-      } else {
-        exemptionNote = noteFromTextarea;
-      }
-    } else {
-      exemptionNote = noteFromTextarea;
-    }
-    if (!exemptionNote) {
-      throw new Error("Wybierz lub wpisz podstawę zwolnienia dla pozycji ze stawka ZW/0%.");
-    }
-  }
-  const client = {
-    name: (invoiceForm.elements.clientName.value || "").trim(),
-    tax_id: (invoiceForm.elements.clientTaxId.value || "").trim(),
-    address_line: (invoiceForm.elements.clientAddress.value || "").trim(),
-    postal_code: (invoiceForm.elements.clientPostalCode.value || "").trim(),
-    city: (invoiceForm.elements.clientCity.value || "").trim(),
-    phone: (invoiceForm.elements.clientPhone.value || "").trim(),
-  };
-
-  return {
-    sale_date: saleDate,
-    payment_term: paymentTerm,
-    client,
-    items,
-    exemption_note: exemptionNote,
-  };
-}
-
-function renderInvoicePreview(invoice) {
-  if (!invoice || !currentBusiness) {
-    invoiceOutput.innerHTML = "<p>Brak danych faktury.</p>";
-    return;
-  }
-
-  const client = invoice.client || {};
-  const hasClientData = client.name || client.address_line || client.postal_code || client.city || client.tax_id;
-
-  const itemsRows = (invoice.items || [])
-    .map((item) => {
-      const quantityDisplay = formatQuantity(item.quantity);
-      const unitDisplay = UNIT_OPTIONS.some((option) => option.value === item.unit) ? item.unit : DEFAULT_UNIT;
-      return `
-        <tr>
-          <td>${item.name}</td>
-          <td>${quantityDisplay}</td>
-          <td>${unitDisplay}</td>
-          <td>${formatCurrency(item.unit_price_net)}</td>
-          <td>${formatCurrency(item.net_total)}</td>
-          <td>${item.vat_label}</td>
-          <td>${formatCurrency(item.vat_amount)}</td>
-          <td>${formatCurrency(item.gross_total)}</td>
-        </tr>`;
-    })
-    .join("");
-
-  const summaryRows = (invoice.summary || [])
-    .map(
-      (entry) =>
-        `<div class="rate-summary-item">
-          <span>${entry.vat_label}</span>
-          <span>Netto: ${formatCurrency(entry.net_total)}</span>
-          <span>VAT: ${formatCurrency(entry.vat_total)}</span>
-          <span>Brutto: ${formatCurrency(entry.gross_total)}</span>
-        </div>`
-    )
-    .join("");
-
-  invoiceOutput.innerHTML = `
-    <div class="invoice-preview-meta">
-      <span><strong>Numer:</strong> ${invoice.invoice_id}</span>
-      <span><strong>Data wystawienia:</strong> ${invoice.issued_at}</span>
-      <span><strong>Data sprzedaży:</strong> ${invoice.sale_date}</span>
-      ${invoice.payment_term ? `<span><strong>Termin płatności:</strong> ${invoice.payment_term} dni</span>` : ''}
-    </div>
-    <div class="invoice-preview-header">
-      <div class="invoice-preview-card">
-        <h4>Nabywca</h4>
-        ${
-          hasClientData
-            ? `
-              <p>${client.name || "---"}</p>
-              <p>${client.address_line || "---"}</p>
-              <p>${client.postal_code || ""} ${client.city || ""}</p>
-              <p>${client.tax_id ? `NIP: ${client.tax_id}` : ""}</p>
-              ${client.phone ? `<p>Tel: ${client.phone}</p>` : ''}
-            `
-            : "<p>Brak danych nabywcy.</p>"
-        }
-      </div>
-      <div class="invoice-preview-card">
-        <h4>Sprzedawca</h4>
-        <p>${currentBusiness.company_name}</p>
-        <p>${currentBusiness.owner_name}</p>
-        <p>${currentBusiness.address_line}</p>
-        <p>${currentBusiness.postal_code} ${currentBusiness.city}</p>
-        <p>NIP: ${currentBusiness.tax_id}</p>
-        <p>Konto: ${currentBusiness.bank_account}</p>
-      </div>
-    </div>
-    <table>
-      <thead>
-        <tr>
-          <th>Nazwa</th>
-          <th>Ilość</th>
-          <th>Jednostka</th>
-          <th>Cena jedn. netto</th>
-          <th>Wartość netto (pozycja)</th>
-          <th>Stawka VAT</th>
-          <th>Kwota VAT (pozycja)</th>
-          <th>Wartość brutto</th>
-        </tr>
-      </thead>
-      <tbody>${itemsRows}</tbody>
-    </table>
-    <div class="rate-summary">
-      <h4>Podsumowanie stawek</h4>
-      ${summaryRows}
-    </div>
-    <div class="invoice-preview-summary">
-      <span>Netto: ${formatCurrency(invoice.totals.net)}</span>
-      <span>VAT: ${formatCurrency(invoice.totals.vat)}</span>
-      <span>Brutto: ${formatCurrency(invoice.totals.gross)}</span>
-    </div>
-    ${
-      invoice.exemption_note
-        ? `<div class="invoice-preview-note"><strong>Podstawa prawna zwolnienia:</strong> ${invoice.exemption_note}</div>`
-        : ""
-    }
-  `;
-}
-
-function drawPartyBox(doc, title, lines, x, y, width, options = {}) {
-  const lineHeight = 5;
-  const wrappedLines = lines.flatMap((line) => doc.splitTextToSize(line, width));
-  const boxHeight = wrappedLines.length * lineHeight + 18;
-  const bgColor = options.bgColor || PDF_COLORS.surface;
-  const plain = options.plain || false;
-
-  if (!plain) {
-    doc.setDrawColor(...PDF_COLORS.border);
-    doc.setFillColor(...bgColor);
-    doc.roundedRect(x - 4, y - 10, width + 8, boxHeight, 2.5, 2.5, "FD");
-  }
-
-  doc.setFontSize(11);
-  doc.setTextColor(...PDF_COLORS.muted);
-  doc.text(title.toUpperCase(), x, y - 2);
-  doc.setFontSize(10);
-  doc.setTextColor(...PDF_COLORS.text);
-
-  let cursor = y + 4;
-  wrappedLines.forEach((line) => {
-    doc.text(line, x, cursor);
-    cursor += lineHeight;
-  });
-
-  return y - 10 + boxHeight;
-}
-
-function arrayBufferToBase64(buffer) {
-  const bytes = new Uint8Array(buffer);
-  const chunkSize = 0x8000;
-  let binary = "";
-  for (let offset = 0; offset < bytes.length; offset += chunkSize) {
-    const chunk = bytes.subarray(offset, Math.min(offset + chunkSize, bytes.length));
-    binary += String.fromCharCode.apply(null, chunk);
-  }
-  return btoa(binary);
-}
-
-const PDF_FONT_FILE = "Roboto-VariableFont_wdth,wght.ttf";
-const PDF_FONT_NAME = "RobotoPolish";
-const PDF_COLORS = {
-  accent: [37, 99, 235],
-  accentMuted: [226, 236, 255],
-  text: [16, 24, 40],
-  muted: [102, 112, 133],
-  border: [215, 222, 236],
-  surface: [249, 251, 255],
-};
-
-async function ensurePdfFont() {
-  if (pdfFontPromise) {
-    return pdfFontPromise;
-  }
-
-  if (!window.jspdf || !window.jspdf.jsPDF) {
-    throw new Error("Biblioteka jsPDF nie została załadowana.");
-  }
-
-  const { jsPDF } = window.jspdf;
-  const loadBase64 = async () => {
-    if (typeof window !== "undefined" && window.PDF_FONT_BASE64) {
-      return window.PDF_FONT_BASE64;
-    }
-    const response = await fetch(`/${encodeURIComponent(PDF_FONT_FILE)}`);
-    if (!response.ok) {
-      throw new Error(`Nie udało się pobrać czcionki Roboto (status ${response.status}).`);
-    }
-    const buffer = await response.arrayBuffer();
-    return arrayBufferToBase64(buffer);
-  };
-
-  pdfFontPromise = loadBase64().then((data) => {
-    pdfFontBase64 = data;
-    return data;
-  });
-
-  return pdfFontPromise;
-}
-
-async function generatePdf(business, invoice, logo) {
-  if (!window.jspdf || !window.jspdf.jsPDF) {
-    alert("Biblioteka jsPDF nie została załadowana. Sprawdź połączenie z internetem.");
-    return;
-  }
-
-  let fontBase64;
-  try {
-    fontBase64 = await ensurePdfFont();
-  } catch (error) {
-    alert(error.message || "Nie udało się przygotować czcionki do PDF.");
-    return;
-  }
-
-  const { jsPDF } = window.jspdf;
-  const doc = new jsPDF({ orientation: "portrait", unit: "mm", format: "a4" });
-  const marginX = 18;
-  let cursorY = 20;
-  const pageWidth = doc.internal.pageSize.getWidth();
-
-  if (!doc.getFontList()[PDF_FONT_NAME]) {
-    const embeddedFont = pdfFontBase64 || fontBase64;
-    doc.addFileToVFS(PDF_FONT_FILE, embeddedFont);
-    doc.addFont(PDF_FONT_FILE, PDF_FONT_NAME, "normal");
-  }
-
-  doc.setFont(PDF_FONT_NAME, "normal");
-  doc.setTextColor(...PDF_COLORS.text);
-  doc.setFontSize(18);
-  doc.text("Faktura", marginX, cursorY + 2);
-  doc.setFontSize(13);
-  doc.text(invoice.invoice_id, marginX, cursorY + 10);
-  doc.setFontSize(10);
-  doc.setTextColor(...PDF_COLORS.muted);
-  const metaLines = [
-    `Data wystawienia: ${invoice.issued_at}`,
-    `Data sprzedaży: ${invoice.sale_date}`,
-  ];
-  if (invoice.payment_term) {
-    metaLines.push(`Termin płatności: ${invoice.payment_term} dni`);
-  }
-  metaLines.forEach((line, index) => {
-    doc.text(line, marginX, cursorY + 18 + index * 5);
-  });
-
-  cursorY += 18 + metaLines.length * 5 + 6;
-  const columnWidth = 85;
-  const sellerX = marginX + columnWidth + 12;
-
-  const clientLines = invoice.client && (invoice.client.name || invoice.client.address_line || invoice.client.city || invoice.client.tax_id || invoice.client.phone)
-    ? [
-        invoice.client.name || "---",
-        invoice.client.address_line || "",
-        `${(invoice.client.postal_code || "").trim()} ${(invoice.client.city || "").trim()}`.trim(),
-        invoice.client.tax_id ? `NIP: ${invoice.client.tax_id}` : "",
-        invoice.client.phone ? `Tel: ${invoice.client.phone}` : "",
-      ].filter((line) => line && line.trim())
-    : ["Brak danych nabywcy"];
-
-  const sellerLines = [
-    business.company_name,
-    business.owner_name,
-    business.address_line,
-    `${business.postal_code} ${business.city}`.trim(),
-    `NIP: ${business.tax_id}`,
-    `Konto: ${business.bank_account}`,
-  ];
-
-  let logoBottom = cursorY;
-  if (logo && logo.data && logo.mime_type) {
-    const format = logo.mime_type === "image/png" ? "PNG" : "JPEG";
-    const dataUrl = logo.data_url || `data:${logo.mime_type};base64,${logo.data}`;
-    try {
-      let logoWidth = 40;
-      let logoHeight = 16;
-      if (doc.getImageProperties) {
-        const props = doc.getImageProperties(dataUrl);
-        if (props?.width && props?.height) {
-          const ratio = props.height / props.width;
-          logoHeight = logoWidth * ratio;
-          if (logoHeight > 20) {
-            logoHeight = 20;
-            logoWidth = logoHeight / ratio;
-          }
-        }
-      }
-      const logoX = sellerX;
-      const logoY = Math.max(cursorY - logoHeight - 12, 18);
-      doc.addImage(dataUrl, format, logoX, logoY, logoWidth, logoHeight);
-      logoBottom = logoY + logoHeight;
-    } catch (error) {
-      console.warn("Nie udało się dodać logo nad sprzedawcą:", error);
-    }
-  }
-
-  const buyerBottom = drawPartyBox(doc, "NABYWCA", clientLines, marginX, cursorY, columnWidth, { plain: true });
-  const sellerBottom = drawPartyBox(doc, "SPRZEDAWCA", sellerLines, sellerX, cursorY, columnWidth, {
-    plain: true,
-  });
-  cursorY = Math.max(buyerBottom, sellerBottom, logoBottom) + 12;
-
-  const tableColumns = [
-    { key: "name", label: "Nazwa", width: 44 },
-    { key: "quantity", label: "Ilość", width: 14 },
-    { key: "unit", label: "Jednostka", width: 14 },
-    { key: "unitNet", label: "Cena jedn. netto", width: 23 },
-    { key: "netTotal", label: "Wartość netto", width: 23 },
-    { key: "vatLabel", label: "Stawka VAT", width: 14 },
-    { key: "vatAmount", label: "Kwota VAT", width: 21 },
-    { key: "grossTotal", label: "Wartość brutto", width: 21 },
-  ];
-  const lineHeight = 5;
-  const headerLineHeight = 4.2;
-  tableColumns.forEach((column) => {
-    column.headerLines = doc.splitTextToSize(column.label, column.width - 4);
-  });
-  const headerHeight = Math.max(...tableColumns.map((column) => column.headerLines.length * headerLineHeight + 3));
-
-  const tableWidth = tableColumns.reduce((sum, column) => sum + column.width, 0);
-
-  doc.setFillColor(...PDF_COLORS.accentMuted);
-  doc.setDrawColor(...PDF_COLORS.border);
-  doc.rect(marginX, cursorY, tableWidth, headerHeight, "F");
-  doc.rect(marginX, cursorY, tableWidth, headerHeight);
-  let offsetX = marginX;
-  doc.setFontSize(10);
-  doc.setTextColor(...PDF_COLORS.text);
-  const rightAlignedColumns = new Set(["quantity", "unit", "unitNet", "netTotal", "vatAmount", "grossTotal"]);
-  tableColumns.forEach((column) => {
-    doc.rect(offsetX, cursorY, column.width, headerHeight);
-    column.headerLines.forEach((line, index) => {
-      const textY = cursorY + 4 + index * headerLineHeight;
-      const textX = rightAlignedColumns.has(column.key) ? offsetX + column.width - 2 : offsetX + 2;
-      doc.text((line || "").trim(), textX, textY, {
-        align: rightAlignedColumns.has(column.key) ? "right" : "left",
-      });
-    });
-    offsetX += column.width;
-  });
-  cursorY += headerHeight;
-
-  const withPercent = (value) => {
-    if (!value) {
-      return "-";
-    }
-    if (/%$/.test(value)) {
-      return value;
-    }
-    if (/^\d+(\.\d+)?$/.test(value)) {
-      return `${value}%`;
-    }
-    return value;
-  };
-
-  const invoiceItems = Array.isArray(invoice.items) ? invoice.items : [];
-  invoiceItems.forEach((item, rowIndex) => {
-    const quantity = formatQuantity(item.quantity);
-    const unitLabel = UNIT_OPTIONS.some((option) => option.value === item.unit) ? item.unit : DEFAULT_UNIT;
-    const unitNet = formatCurrency(item.unit_price_net);
-    const netTotal = formatCurrency(item.net_total);
-    const vatAmount = formatCurrency(item.vat_amount);
-    const grossTotal = formatCurrency(item.gross_total);
-
-    const wrapText = (text, width) => {
-      const available = Math.max(width - 4, 6);
-      return doc
-        .splitTextToSize(text ?? "", available)
-        .map((line) => line.trim());
-    };
-
-    const columnData = tableColumns.map((column) => {
-      switch (column.key) {
-        case "name":
-          return wrapText(item.name, column.width - 4);
-        case "quantity":
-          return wrapText(quantity, column.width);
-        case "unit":
-          return wrapText(unitLabel, column.width);
-        case "unitNet":
-          return wrapText(unitNet, column.width);
-        case "netTotal":
-          return wrapText(netTotal, column.width);
-        case "vatLabel":
-          return wrapText(withPercent(item.vat_label), column.width);
-        case "vatAmount":
-          return wrapText(vatAmount, column.width);
-        case "grossTotal":
-          return wrapText(grossTotal, column.width);
-        default:
-          return wrapText("", column.width);
-      }
-    });
-
-    const rowHeight = Math.max(...columnData.map((data) => data.length)) * lineHeight + 2;
-    offsetX = marginX;
-    if (rowIndex % 2 === 1) {
-      doc.setFillColor(248, 250, 253);
-      doc.rect(marginX, cursorY, tableWidth, rowHeight, "F");
-    }
-    tableColumns.forEach((column, index) => {
-      doc.rect(offsetX, cursorY, column.width, rowHeight);
-      const lines = columnData[index];
-      lines.forEach((line, lineIndex) => {
-          const textY = cursorY + (lineIndex + 1) * lineHeight;
-          const content = (line || "").trim();
-          const alignRight = rightAlignedColumns.has(column.key);
-          const textX = alignRight ? offsetX + column.width - 2 : offsetX + 2;
-          doc.text(content, textX, textY, { align: alignRight ? "right" : "left" });
-      });
-      offsetX += column.width;
-    });
-
-    cursorY += rowHeight;
-  });
-
-  cursorY += 10;
-  doc.setFontSize(11);
-  doc.text("Podsumowanie stawek", marginX, cursorY);
-  cursorY += 6;
-
-  const summaryEntries = Array.isArray(invoice.summary) ? invoice.summary : [];
-  doc.setFontSize(10);
-  doc.setTextColor(...PDF_COLORS.text);
-  summaryEntries.forEach((entry) => {
-    const summaryLine = `${withPercent(entry.vat_label)}  |  Netto: ${formatCurrency(entry.net_total)}   VAT: ${formatCurrency(entry.vat_total)}   Brutto: ${formatCurrency(entry.gross_total)}`;
-    const wrapped = doc.splitTextToSize(summaryLine, 170);
-    wrapped.forEach((line) => {
-      doc.text((line || "").trim(), marginX, cursorY);
-      cursorY += lineHeight;
-    });
-    cursorY += 2;
-  });
-  cursorY += 6;
-
-  const totals = [
-    { label: "Netto", value: formatCurrency(invoice.totals.net), variant: "muted" },
-    { label: "VAT", value: formatCurrency(invoice.totals.vat), variant: "muted" },
-    { label: "Brutto", value: formatCurrency(invoice.totals.gross), variant: "accent" },
-  ];
-  const chipWidth = 54;
-  const chipHeight = 20;
-  doc.setFontSize(10);
-  totals.forEach((chip, index) => {
-    const x = marginX + index * (chipWidth + 12);
-    if (chip.variant === "accent") {
-      doc.setFillColor(...PDF_COLORS.accent);
-      doc.setTextColor(255, 255, 255);
-    } else {
-      doc.setFillColor(...PDF_COLORS.surface);
-      doc.setTextColor(...PDF_COLORS.muted);
-    }
-    doc.roundedRect(x, cursorY, chipWidth, chipHeight, 4, 4, "F");
-    doc.text(chip.label.toUpperCase(), x + 3, cursorY + 6);
-    doc.setFontSize(chip.variant === "accent" ? 12 : 11);
-    if (chip.variant === "accent") {
-      doc.setTextColor(255, 255, 255);
-    } else {
-      doc.setTextColor(...PDF_COLORS.text);
-    }
-    doc.text(chip.value, x + 3, cursorY + 14);
-    doc.setFontSize(10);
-  });
-  cursorY += chipHeight + 12;
-
-  if (invoice.exemption_note) {
-    doc.setFontSize(10);
-    doc.setTextColor(...PDF_COLORS.text);
-    const noteLines = doc.splitTextToSize(`Podstawa prawna zwolnienia: ${invoice.exemption_note}`, 170);
-    doc.text(noteLines, marginX, cursorY);
-  }
-
-  doc.save(`${invoice.invoice_id}.pdf`);
-}
-
-async function loadBusinessData() {
-  const data = await apiRequest("/api/business", {}, true);
-  currentBusiness = data.business;
-  renderBusinessDisplay(currentBusiness);
-  fillBusinessForm(currentBusiness);
-  setBusinessFormVisibility(false);
-}
-
-async function loadLogo() {
-  try {
-    const data = await apiRequest("/api/logo", {}, true);
-    currentLogo = data.logo || null;
-  } catch (error) {
-    console.error("Nie udało się pobrać logo:", error);
-    currentLogo = null;
-  }
-  updateLogoPreview();
-}
-
-function resetInvoiceForm() {
-  invoiceForm.reset();
-  customExemptionNote = "";
-  updateExemptionVisibility(false);
-  itemsBody.innerHTML = "";
-  createItemRow();
-  const now = new Date();
-  const year = now.getFullYear();
-  const month = String(now.getMonth() + 1).padStart(2, "0");
-  const day = String(now.getDate()).padStart(2, "0");
-  if (invoiceForm.elements.saleDate) {
-    invoiceForm.elements.saleDate.value = `${year}-${month}-${day}`;
-  }
-  updateTotals();
-}
-
-async function bootstrapApp() {
-  try {
-    await loadBusinessData();
-    await loadLogo();
-    exitInvoiceEdit();
-    resetInvoiceForm();
-    invoiceResult.classList.add("hidden");
-    lastInvoice = null;
-    await refreshInvoices();
-    await refreshSummary();
-    updateLoginLabel();
-    setAppState("app");
-    activeView = "invoice-builder";
-    setActiveView(activeView);
-  } catch (error) {
-    console.error(error);
-    authToken = null;
-    currentLogin = "";
-    sessionStorage.removeItem("invoiceAuthToken");
-    sessionStorage.removeItem("invoiceLogin");
-    showFeedback(loginFeedback, error.message || "Nie udało się pobrać danych konta.");
-    setAppState("auth");
-  }
-}
-
-async function initialize() {
-  exitInvoiceEdit();
-  resetInvoiceForm();
-  updateLogoPreview();
-  updateSummaryCards({});
-  updateSummaryChart({});
-  setActiveView("invoice-builder");
-  setAppState("auth");
-  closeRegisterPanel({ resetForm: true, focusTrigger: false });
-  clearFeedback(registerFeedback);
-  clearFeedback(loginFeedback);
-  if (legacyLoginHint) {
-    legacyLoginHint.classList.add("hidden");
-    legacyLoginHint.textContent = "";
-  }
-  if (authToken) {
-    await bootstrapApp().catch((error) => {
-      console.error(error);
-      showFeedback(registerFeedback, "Nie uda?o si? nawi?za? po??czenia z serwerem.");
-    });
-  }
-}
-
-
-if (registerForm && registerFeedback && loginFeedback) {
-  registerForm.addEventListener("submit", async (event) => {
-    event.preventDefault();
-    clearFeedback(registerFeedback);
-    clearFeedback(loginFeedback);
-
-    const formData = new FormData(registerForm);
-    const emailValue = formData.get("email")?.toString().trim() ?? "";
-    const password = formData.get("password")?.toString() ?? "";
-    const confirmPassword = formData.get("confirm_password")?.toString() ?? "";
-
-    if (!emailValue) {
-      showFeedback(registerFeedback, "Podaj adres email.");
-      return;
-    }
-    if (password !== confirmPassword) {
-      showFeedback(registerFeedback, "Hasła musza byc identyczne.");
-      return;
-    }
-
-    if (password.trim().length < 4) {
-      showFeedback(registerFeedback, "Hasło musi miec co najmniej 4 znaki.");
-      return;
-    }
-
-    const payload = {
-      email: emailValue,
-      password,
-      confirm_password: confirmPassword,
-      company_name: formData.get("company_name")?.toString().trim(),
-      owner_name: formData.get("owner_name")?.toString().trim(),
-      address_line: formData.get("address_line")?.toString().trim(),
-      postal_code: formData.get("postal_code")?.toString().trim(),
-      city: formData.get("city")?.toString().trim(),
-      tax_id: formData.get("tax_id")?.toString().trim(),
-      bank_account: formData.get("bank_account")?.toString().trim(),
-    };
-
-    try {
-      await apiRequest("/api/register", { method: "POST", body: payload });
-      showFeedback(registerFeedback, "Konto utworzone. Możesz sie zalogowac.", "success");
-      if (loginForm && loginForm.elements.email) {
-        loginForm.elements.email.value = emailValue;
-      }
-      registerForm.reset();
-      setTimeout(() => {
-        closeRegisterPanel({ resetForm: true, focusTrigger: false });
-        clearFeedback(registerFeedback);
-        clearFeedback(loginFeedback);
-        showFeedback(loginFeedback, "Konto utworzone. Zaloguj się haslem.", "success");
-        if (loginForm) {
-          const passwordInput = loginForm.elements.password;
-          if (passwordInput) {
-            passwordInput.focus();
-          }
-        }
-      }, 1600);
-    } catch (error) {
-      showFeedback(registerFeedback, error.message || "Nie udało się utworzyć konta.");
-    }
-  });
-}
-
-if (loginForm && loginFeedback) {
-  const setLoginSubmittingState = (isSubmitting) => {
-    if (!loginSubmitButton) {
-      return;
-    }
-    if (isSubmitting) {
-      loginSubmitButton.disabled = true;
-      loginSubmitButton.setAttribute("data-loading", "true");
-      loginSubmitButton.textContent = "Logowanie...";
-    } else {
-      loginSubmitButton.disabled = false;
-      loginSubmitButton.textContent = loginSubmitButtonDefaultText;
-      loginSubmitButton.removeAttribute("data-loading");
-    }
-  };
-
-  loginForm.addEventListener("submit", async (event) => {
-    event.preventDefault();
-    clearFeedback(loginFeedback);
-
-    const emailElement = loginForm.elements.email;
-    const emailValue = emailElement ? emailElement.value.trim() : "";
-    const password = loginForm.elements.password.value;
-
-    if (!emailValue) {
-      showFeedback(loginFeedback, "Podaj adres email.");
-      return;
-    }
-
-    if (!password) {
-      showFeedback(loginFeedback, "Podaj hasło.");
-      return;
-    }
-
-    setLoginSubmittingState(true);
-
-    try {
-      const response = await apiRequest("/api/login", { method: "POST", body: { email: emailValue, password } });
-      authToken = response.token;
-      currentLogin = response.email || response.login || emailValue;
-      sessionStorage.setItem("invoiceAuthToken", authToken);
-      sessionStorage.setItem("invoiceLogin", currentLogin);
-      loginForm.reset();
-      await bootstrapApp();
-    } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : String(error || "");
-      let feedbackMessage = errorMessage || "Logowanie nie powiodło się.";
-      if (/nieprawidlowy (login|email) lub hasło/i.test(errorMessage)) {
-        feedbackMessage = "Podany email lub hasło są nieprawidłowe. Utwórz konto, jeśli jeszcze go nie masz.";
-      } else if (/brak autoryzacji/i.test(errorMessage) || /brak tokenu autoryzacyjnego/i.test(errorMessage)) {
-        feedbackMessage = "Sesja wygasła. Zaloguj się ponownie.";
-      } else if (/failed to fetch|networkerror/i.test(errorMessage) || error instanceof TypeError) {
-        feedbackMessage = "Nie udało się nawiązać połączenia z serwerem. Sprawdź, czy aplikacja serwerowa jest uruchomiona.";
-      }
-      showFeedback(loginFeedback, feedbackMessage);
-    } finally {
-      setLoginSubmittingState(false);
-    }
-  });
-}
-
-if (toggleBusinessFormButton && businessForm && businessFeedback) {
-  toggleBusinessFormButton.addEventListener("click", () => {
-    const isVisible = !businessForm.classList.contains("hidden");
-    if (!isVisible) {
-      setBusinessFormVisibility(true, { preserveFeedback: true });
-    } else {
-      setBusinessFormVisibility(false);
-    }
-  });
-}
-
-if (cancelBusinessUpdateButton && businessForm && businessFeedback && toggleBusinessFormButton) {
-  cancelBusinessUpdateButton.addEventListener("click", () => {
-    setBusinessFormVisibility(false);
-  });
-}
-
-if (businessForm && businessFeedback) {
-  businessForm.addEventListener("submit", async (event) => {
-    event.preventDefault();
-    clearFeedback(businessFeedback);
-
-    const formData = new FormData(businessForm);
-    const payload = {
-      company_name: formData.get("company_name")?.toString().trim(),
-      owner_name: formData.get("owner_name")?.toString().trim(),
-      address_line: formData.get("address_line")?.toString().trim(),
-      postal_code: formData.get("postal_code")?.toString().trim(),
-      city: formData.get("city")?.toString().trim(),
-      tax_id: formData.get("tax_id")?.toString().trim(),
-      bank_account: formData.get("bank_account")?.toString().trim(),
-    };
-
-    try {
-      await apiRequest("/api/business", { method: "POST", body: payload }, true);
-      await loadBusinessData();
-      setBusinessFormVisibility(false, { preserveFeedback: true });
-      showFeedback(businessFeedback, "Dane sprzedawcy zaktualizowane.", "success");
-      setTimeout(() => clearFeedback(businessFeedback), 2000);
-    } catch (error) {
-      showFeedback(businessFeedback, error.message || "Nie udało się zaktualizować danych.");
-    }
-  });
-}
-
-if (exemptionReasonSelect) {
-  populateExemptionReasons();
-  let previousReasonValue = exemptionReasonSelect.value;
-  applyExemptionReasonSelection({ preserveCustom: true });
-  exemptionReasonSelect.addEventListener("change", () => {
-    if (previousReasonValue === "custom" && exemptionNoteInput) {
-      customExemptionNote = exemptionNoteInput.value.trim();
-    }
-    previousReasonValue = exemptionReasonSelect.value;
-    applyExemptionReasonSelection();
-    if (exemptionReasonSelect.value === "custom" && exemptionNoteInput) {
-      exemptionNoteInput.focus();
-    }
-  });
-}
-
-if (exemptionNoteInput) {
-  exemptionNoteInput.addEventListener("input", () => {
-    if (exemptionReasonSelect && exemptionReasonSelect.value === "custom") {
-      customExemptionNote = exemptionNoteInput.value;
-    }
-  });
-}
-
-if (invoiceForm) {
-  invoiceForm.addEventListener("submit", async (event) => {
-    event.preventDefault();
-    try {
-      const payload = collectInvoicePayload();
-      let response;
-      if (editingInvoiceId) {
-        response = await apiRequest(`/api/invoices/${encodeURIComponent(editingInvoiceId)}`, { method: "PUT", body: payload }, true);
-        exitInvoiceEdit();
-      } else {
-        response = await apiRequest("/api/invoices", { method: "POST", body: payload }, true);
-      }
-      lastInvoice = response.invoice;
-      renderInvoicePreview(lastInvoice);
-      if (invoiceResult) {
-        invoiceResult.classList.remove("hidden");
-      }
-      await refreshInvoices();
-      await refreshSummary();
-      resetInvoiceForm();
-    } catch (error) {
-      alert(error.message || "Nie udało się zapisać faktury.");
-    }
-  });
-}
-
-if (addItemButton) {
-  addItemButton.addEventListener("click", () => {
-    createItemRow();
-  });
-}
-
-if (downloadButton) {
-  downloadButton.addEventListener("click", async () => {
-    if (!lastInvoice || !currentBusiness) {
-      alert("Brak faktury do pobrania. Wygeneruj ją najpierw.");
-      return;
-    }
-    await generatePdf(currentBusiness, lastInvoice, currentLogo);
-  });
-}
-
-if (logoutButton) {
-  logoutButton.addEventListener("click", () => {
-    authToken = null;
-    currentLogin = "";
-    sessionStorage.removeItem("invoiceAuthToken");
-    sessionStorage.removeItem("invoiceLogin");
-    lastInvoice = null;
-    currentBusiness = null;
-    currentLogo = null;
-    invoicesCache = [];
-    exitInvoiceEdit();
-    resetInvoiceForm();
-    setBusinessFormVisibility(false);
-    if (invoiceResult) {
-      invoiceResult.classList.add("hidden");
-    }
-    updateLogoPreview();
-    updateLoginLabel();
-    renderInvoicesTable([]);
-    updateSummaryCards({});
-    updateSummaryChart({});
-    closeRegisterPanel({ resetForm: true, focusTrigger: true });
-    clearFeedback(registerFeedback);
-    clearFeedback(loginFeedback);
-    clearFeedback(businessFeedback);
-    clearFeedback(logoFeedback);
-    clearFeedback(dashboardFeedback);
-    setAppState("auth");
-  });
-}
-
-appNavButtons.forEach((button) => {
-  button.addEventListener("click", () => {
-    setActiveView(button.dataset.view);
-  });
-});
-
-if (filterStartDate) {
-  filterStartDate.addEventListener("change", applyInvoiceFilters);
-}
-if (filterEndDate) {
-  filterEndDate.addEventListener("change", applyInvoiceFilters);
-}
-if (clearFiltersButton) {
-  clearFiltersButton.addEventListener("click", () => {
-    if (filterStartDate) {
-      filterStartDate.value = "";
-    }
-    if (filterEndDate) {
-      filterEndDate.value = "";
-    }
-    applyInvoiceFilters();
-  });
-}
-
-if (showRegisterButton) {
-  showRegisterButton.addEventListener("click", () => {
-    openRegisterPanel();
-  });
-}
-
-if (backToLoginButton) {
-  backToLoginButton.addEventListener("click", () => {
-    closeRegisterPanel({ resetForm: false, focusTrigger: true });
-  });
-}
-
-if (cancelRegisterButton) {
-  cancelRegisterButton.addEventListener("click", () => {
-    closeRegisterPanel({ resetForm: true, focusTrigger: true });
-  });
-}
-
-if (logoInput) {
-  logoInput.addEventListener("change", (event) => {
-    const file = event.target.files?.[0];
-    if (!file) {
-      return;
-    }
-    clearFeedback(logoFeedback);
-    if (file.size > maxLogoSize) {
-      showFeedback(logoFeedback, `Logo jest zbyt duze. Maksymalny rozmiar to ${(maxLogoSize / 1024).toFixed(0)} KB.`);
-      logoInput.value = "";
-      return;
-    }
-    const reader = new FileReader();
-    reader.onload = async () => {
-      try {
-        const base64 = reader.result?.toString();
-        if (!base64) {
-          throw new Error("Nie udało się odczytać pliku.");
-        }
-        const response = await apiRequest(
-          "/api/logo",
-          {
-            method: "POST",
-            body: {
-              filename: file.name,
-              mime_type: file.type,
-              content: base64,
-            },
-          },
-          true
-        );
-        currentLogo = response.logo;
-        updateLogoPreview();
-        showFeedback(logoFeedback, "Logo zapisane.", "success");
-      } catch (error) {
-        showFeedback(logoFeedback, error.message || "Nie udało się zapisać logo.");
-      } finally {
-        logoInput.value = "";
-      }
-    };
-    reader.onerror = () => {
-      showFeedback(logoFeedback, "Nie udało się wczytać pliku logo.");
-      logoInput.value = "";
-    };
-    reader.readAsDataURL(file);
-  });
-}
-
-if (removeLogoButton) {
-  removeLogoButton.addEventListener("click", async () => {
-    clearFeedback(logoFeedback);
-    if (!currentLogo) {
-      showFeedback(logoFeedback, "Brak logo do usunięcia.");
-      return;
-    }
-    try {
-      await apiRequest("/api/logo", { method: "DELETE" }, true);
-      currentLogo = null;
-      updateLogoPreview();
-      showFeedback(logoFeedback, "Logo usunięte.", "success");
-    } catch (error) {
-      showFeedback(logoFeedback, error.message || "Nie udało się usunąć logo.");
-    }
-  });
-}
-
-if (cancelEditInvoiceButton) {
-  cancelEditInvoiceButton.addEventListener("click", () => {
-    exitInvoiceEdit();
-    resetInvoiceForm();
-  });
-}
-
-if (clientSearchInput) {
-  clientSearchInput.addEventListener("input", handleClientSearchInput);
-  clientSearchInput.addEventListener("focus", () => {
-    if ((clientSearchInput.value || "").trim().length >= 2) {
-      requestClientSuggestions(clientSearchInput.value);
-    }
-  });
-}
-
-document.addEventListener("click", (event) => {
-  if (!clientSuggestionsContainer || !clientSearchInput) {
-    return;
-  }
-  if (
-    clientSuggestionsContainer.contains(event.target) ||
-    clientSearchInput === event.target ||
-    clientSearchInput.contains(event.target)
-  ) {
-    return;
-  }
-  hideClientSuggestions();
-});
-
-initialize().catch((error) => {
-  console.error(error);
-  showFeedback(registerFeedback, "Nie udało się uruchomić aplikacji.");
-});

requirements.txt

@@ -1,2 +1,6 @@
-Flask==3.0.2
-psycopg2-binary==2.9.9
+Flask>=2.3,<3.0
+
+SQLAlchemy
+psycopg2-binary
+uvicorn
+fastapi

server.py

@@ -1,73 +1,75 @@
-import base64
-import binascii
-import hashlib
-import json
-import os
-import re
-import uuid
-from datetime import date, datetime, timedelta, timezone
-from decimal import Decimal, ROUND_HALF_UP, getcontext
-from pathlib import Path
-from typing import Any, Dict, List, Optional, Tuple
-
-from flask import Flask, jsonify, request, send_from_directory
-
-from db import (
-    create_account,
-    execute,
-    fetch_all,
-    fetch_one,
-    fetch_business_logo,
-    insert_invoice,
-    search_clients,
-    update_business,
-    update_business_logo,
-    upsert_client,
-)
-
-APP_ROOT = Path(__file__).parent.resolve()
-DATA_DIR = Path(os.environ.get("DATA_DIR", APP_ROOT))
-DATA_FILE = DATA_DIR / "web_invoice_store.json"
-INVOICE_HISTORY_LIMIT = 200
-MAX_LOGO_SIZE = 512 * 1024  # 512 KB
-TOKEN_TTL = timedelta(hours=12)
-ALLOWED_LOGO_MIME_TYPES = {"image/png", "image/jpeg"}
-
-DATABASE_AVAILABLE = bool(os.environ.get("NEON_DATABASE_URL"))
-
-VAT_RATES: Dict[str, Optional[Decimal]] = {
-    "23": Decimal("0.23"),
-    "8": Decimal("0.08"),
-    "5": Decimal("0.05"),
-    "0": Decimal("0.00"),
-    "ZW": None,
-    "NP": None,
-}
-
-DEFAULT_UNIT = "szt."
-ALLOWED_UNITS = {"szt.", "godz."}
-PASSWORD_MIN_LENGTH = 4
-
-SESSION_TOKENS: Dict[str, Dict[str, Any]] = {}
-
-ALLOWED_STATIC = {
-    "index.html",
-    "styles.css",
-    "main.js",
-    "favicon.ico",
-    "Roboto-VariableFont_wdth,wght.ttf",
-}
-
-
-app = Flask(__name__, static_folder=str(APP_ROOT), static_url_path="")
-
-getcontext().prec = 10
-
-
-def _quantize(value: Decimal) -> Decimal:
-    return value.quantize(Decimal("0.01"), rounding=ROUND_HALF_UP)
-
-
+import hashlib
+import json
+import os
+from flask import Flask, render_template, request, redirect, url_for
+from sqlalchemy import create_engine, text
+
+from flask import render_template
+
+app = Flask(__name__)
+engine = create_engine(os.environ["DATABASE_URL"], pool_pre_ping=True)
+
+import uuid
+from datetime import datetime
+from decimal import Decimal, ROUND_HALF_UP, getcontext
+from pathlib import Path
+from typing import Any, Dict, List, Optional, Tuple
+
+from flask import Flask, jsonify, request, send_from_directory
+
+APP_ROOT = Path(__file__).parent.resolve()
+DATA_DIR = Path(os.environ.get("DATA_DIR", APP_ROOT))
+DATA_FILE = DATA_DIR / "web_invoice_store.json"
+INVOICE_HISTORY_LIMIT = 200
+
+VAT_RATES: Dict[str, Optional[Decimal]] = {
+    "23": Decimal("0.23"),
+    "8": Decimal("0.08"),
+    "5": Decimal("0.05"),
+    "0": Decimal("0.00"),
+    "ZW": None,
+    "NP": None,
+}
+
+SESSION_TOKENS: Dict[str, datetime] = {}
+
+ALLOWED_STATIC = {
+    "index.html",
+    "styles.css",
+    "main.js",
+    "favicon.ico",
+    "Roboto-VariableFont_wdth,wght.ttf",
+}
+
+@app.route("/")
+def index():
+    # Pobierz ostatnie notatki i pokaż w HTML
+    with engine.begin() as conn:
+        rows = conn.execute(text(
+            "SELECT id, body, created_at FROM notes ORDER BY id DESC LIMIT 20"
+        )).mappings().all()
+    return render_template("index.html", notes=rows)
+
+    if __name__ == "__main__":  # Sprawdzamy, czy uruchamiamy główny skrypt
+        port = int(os.environ.get("PORT", "7860"))  # Wcięcie pod warunkiem
+        app.run(host="0.0.0.0", port=port, debug=False)  # Wcięcie pod warunkiem
+
+
+@app.post("/add")
+def add():
+    body = request.form.get("body","").strip()
+    if body:
+        with engine.begin() as conn:
+            conn.execute(text("INSERT INTO notes (body) VALUES (:b)"), {"b": body})
+    return redirect(url_for("index"))
+
+getcontext().prec = 10
+
+
+def _quantize(value: Decimal) -> Decimal:
+    return value.quantize(Decimal("0.01"), rounding=ROUND_HALF_UP)
+
+
 def _decimal(value: Any) -> Decimal:
     try:
         return Decimal(str(value))
@@ -75,135 +77,201 @@ def _decimal(value: Any) -> Decimal:
         raise ValueError(f"Niepoprawna wartosc liczby: {value}") from error
 
 
-def _format_decimal_str(value: Any, default: str = "0.00") -> str:
-    if value in (None, ""):
-        return default
-    if isinstance(value, Decimal):
-        return str(_quantize(value))
+def hash_password(password: str) -> str:
+    return hashlib.sha256(password.encode("utf-8")).hexdigest()
+
+
+def load_store() -> Dict[str, Any]:
+    if not DATA_FILE.exists():
+        return {"business": None, "password_hash": None, "invoices": []}
+    with DATA_FILE.open("r", encoding="utf-8") as handle:
+        return json.load(handle)
+
+
+def save_store(data: Dict[str, Any]) -> None:
+    DATA_FILE.parent.mkdir(parents=True, exist_ok=True)
+    with DATA_FILE.open("w", encoding="utf-8") as handle:
+        json.dump(data, handle, ensure_ascii=False, indent=2)
+
+
+def ensure_configured(data: Dict[str, Any]) -> None:
+    if not data.get("business") or not data.get("password_hash"):
+        raise ValueError("Aplikacja nie zostala skonfigurowana.")
+
+
+def parse_iso_date(value: Optional[str]) -> Optional[str]:
+    if not value:
+        return None
     try:
-        return str(_quantize(Decimal(str(value))))
-    except Exception:
-        return str(value)
+        parsed = datetime.fromisoformat(value)
+        return parsed.strftime("%Y-%m-%d")
+    except ValueError:
+        return None
 
 
-def hash_password(password: str) -> str:
-    return hashlib.sha256(password.encode("utf-8")).hexdigest()
-
-
-EMAIL_PATTERN = re.compile(r"^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$")
-
-
-def normalize_email(raw_email: str) -> Tuple[str, str]:
-    display_email = (raw_email or "").strip()
-    if not display_email:
-        raise ValueError("Email nie moze byc pusty.")
-    if not EMAIL_PATTERN.fullmatch(display_email):
-        raise ValueError("Podaj poprawny adres email.")
-    return display_email.lower(), display_email
-
-
-def sanitize_filename(filename: Optional[str]) -> str:
-    if not filename:
-        return "logo"
-    name = str(filename).split("/")[-1].split("\\")[-1]
-    sanitized = re.sub(r"[^A-Za-z0-9._-]", "_", name).strip("._")
-    return sanitized or "logo"
-
-
-def find_account_identifier(accounts: Dict[str, Any], identifier: str) -> Tuple[Optional[str], Optional[Dict[str, Any]]]:
-    key = (identifier or "").strip().lower()
-    if not key:
-        return None, None
-    account = accounts.get(key)
-    if account:
-        return key, account
-    for login_key, candidate in accounts.items():
-        candidate_login = (candidate.get("login") or "").strip().lower()
-        candidate_email = (candidate.get("email") or "").strip().lower()
-        if key in {candidate_login, candidate_email}:
-            return login_key, candidate
-    return None, None
-
-
-def load_store() -> Dict[str, Any]:
-    if not DATA_FILE.exists():
-        return {"accounts": {}}
-    try:
-        with DATA_FILE.open("r", encoding="utf-8") as handle:
-            data = json.load(handle)
-    except json.JSONDecodeError:
-        raise ValueError("Plik z danymi jest uszkodzony.")
-    return data
-
-
-def save_store(data: Dict[str, Any]) -> None:
-    DATA_DIR.mkdir(parents=True, exist_ok=True)
-    tmp_path = DATA_FILE.with_suffix(".tmp")
-    with tmp_path.open("w", encoding="utf-8") as handle:
-        json.dump(data, handle, ensure_ascii=False, indent=2)
-    tmp_path.replace(DATA_FILE)
-
-
-def get_account(data: Dict[str, Any], login_key: str) -> Dict[str, Any]:
-    accounts = data.get("accounts") or {}
-    account = accounts.get(login_key)
-    if not account:
-        raise KeyError("Nie znaleziono konta.")
-    return account
-
-
-def get_account_row(login_key: str) -> Dict[str, Any]:
-    row = fetch_one("SELECT id, login FROM accounts WHERE login = %s", (login_key,))
-    if not row:
-        raise KeyError("Nie znaleziono konta.")
-    return row
-
-
-def get_business_profile(account_id: int) -> Optional[Dict[str, Any]]:
-    return fetch_one(
-        """
-        SELECT company_name, owner_name, address_line, postal_code,
-               city, tax_id, bank_account
-        FROM business_profiles
-        WHERE account_id = %s
-        """,
-        (account_id,),
-    )
-
-
-def require_auth() -> str:
-    auth_header = request.headers.get("Authorization")
-    if not auth_header or not auth_header.startswith("Bearer "):
-        raise PermissionError("Brak tokenu.")
-    token = auth_header.split(" ", 1)[1].strip()
-    session = SESSION_TOKENS.get(token)
-    if not session:
-        raise PermissionError("Nieprawidlowy token.")
-    if session["expires_at"] < datetime.utcnow():
-        SESSION_TOKENS.pop(token, None)
-        raise PermissionError("Token wygasl.")
-    return session["login_key"]
-
-
-@app.route("/")
-def index() -> Any:
-    return send_from_directory(app.static_folder, "index.html")
-
-
-@app.route("/<path:filename>")
-def static_files(filename: str) -> Any:
-    if filename not in ALLOWED_STATIC:
-        return jsonify({"error": "Nie ma takiego zasobu."}), 404
-    return send_from_directory(app.static_folder, filename)
-
-
-@app.route("/api/register", methods=["POST"])
-def api_register() -> Any:
+def compute_invoice_items(items_payload: List[Dict[str, Any]]) -> Tuple[List[Dict[str, Any]], Dict[str, Dict[str, Decimal]]]:
+    if not items_payload:
+        raise ValueError("Dodaj przynajmniej jedna pozycje.")
+
+    computed_items: List[Dict[str, Any]] = []
+    summary: Dict[str, Dict[str, Decimal]] = {}
+
+    for raw in items_payload:
+        name = (raw.get("name") or "").strip()
+        if not name:
+            raise ValueError("Kazda pozycja musi miec nazwe.")
+
+        quantity = _decimal(raw.get("quantity", "0"))
+        if quantity <= 0:
+            raise ValueError("Ilosc musi byc wieksza od zera.")
+
+        vat_code = str(raw.get("vat_code", "")).upper()
+        if vat_code not in VAT_RATES:
+            raise ValueError(f"Nieznana stawka VAT: {vat_code}")
+
+        unit_price_gross = _decimal(raw.get("unit_price_gross", "0"))
+        if unit_price_gross <= 0:
+            raise ValueError("Cena brutto musi byc wieksza od zera.")
+
+        rate = VAT_RATES[vat_code]
+        if rate is None:
+            unit_price_net = unit_price_gross
+            vat_amount = Decimal("0.00")
+        else:
+            unit_price_net = unit_price_gross / (Decimal("1.00") + rate)
+            vat_amount = unit_price_gross - unit_price_net
+
+        unit_price_net = _quantize(unit_price_net)
+        unit_price_gross = _quantize(unit_price_gross)
+
+        net_total = _quantize(unit_price_net * quantity)
+        vat_amount_total = _quantize(vat_amount * quantity if rate is not None else Decimal("0.00"))
+        gross_total = _quantize(unit_price_gross * quantity)
+
+        vat_label = "ZW" if vat_code in {"ZW", "0"} else ("NP" if vat_code == "NP" else f"{vat_code}%")
+
+        computed_items.append(
+            {
+                "name": name,
+                "quantity": str(_quantize(quantity)),
+                "vat_code": vat_code,
+                "vat_label": vat_label,
+                "unit_price_net": str(unit_price_net),
+                "unit_price_gross": str(unit_price_gross),
+                "net_total": str(net_total),
+                "vat_amount": str(vat_amount_total),
+                "gross_total": str(gross_total),
+            }
+        )
+
+        summary_key = vat_label
+        bucket = summary.setdefault(summary_key, {"net": Decimal("0.00"), "vat": Decimal("0.00"), "gross": Decimal("0.00")})
+        bucket["net"] += net_total
+        bucket["vat"] += vat_amount_total
+        bucket["gross"] += gross_total
+
+    return computed_items, summary
+
+
+def computed_summary_to_serializable(summary: Dict[str, Dict[str, Decimal]]) -> List[Dict[str, str]]:
+    serialized = []
+    for vat_label, values in summary.items():
+        serialized.append(
+            {
+                "vat_label": vat_label,
+                "net_total": str(_quantize(values["net"])),
+                "vat_total": str(_quantize(values["vat"])),
+                "gross_total": str(_quantize(values["gross"])),
+            }
+        )
+    serialized.sort(key=lambda item: item["vat_label"])
+    return serialized
+
+
+def compute_invoice(payload: Dict[str, Any], business: Dict[str, Any]) -> Dict[str, Any]:
+    items_payload = payload.get("items", [])
+    computed_items, summary = compute_invoice_items(items_payload)
+
+    net_sum = sum(Decimal(item["net_total"]) for item in computed_items)
+    vat_sum = sum(Decimal(item["vat_amount"]) for item in computed_items)
+    gross_sum = sum(Decimal(item["gross_total"]) for item in computed_items)
+
+    issued_at = datetime.now()
+    invoice_id = issued_at.strftime("FV-%Y%m%d-%H%M%S")
+
+    sale_date = parse_iso_date(payload.get("sale_date")) or issued_at.strftime("%Y-%m-%d")
+    client_payload = payload.get("client") or {}
+    client = {
+        "name": (client_payload.get("name") or "").strip(),
+        "address_line": (client_payload.get("address_line") or "").strip(),
+        "postal_code": (client_payload.get("postal_code") or "").strip(),
+        "city": (client_payload.get("city") or "").strip(),
+        "tax_id": (client_payload.get("tax_id") or "").strip(),
+    }
+
+    invoice = {
+        "invoice_id": invoice_id,
+        "issued_at": issued_at.strftime("%Y-%m-%d %H:%M"),
+        "sale_date": sale_date,
+        "items": computed_items,
+        "summary": computed_summary_to_serializable(summary),
+        "totals": {
+            "net": str(_quantize(net_sum)),
+            "vat": str(_quantize(vat_sum)),
+            "gross": str(_quantize(gross_sum)),
+        },
+        "client": client,
+        "exemption_note": (payload.get("exemption_note") or "").strip(),
+    }
+
+    return invoice
+
+
+def create_token() -> str:
+    token = uuid.uuid4().hex
+    SESSION_TOKENS[token] = datetime.now()
+    return token
+
+
+def get_token() -> Optional[str]:
+    header = request.headers.get("Authorization", "")
+    if not header.startswith("Bearer "):
+        return None
+    return header.split(" ", 1)[1].strip()
+
+
+def require_auth() -> str:
+    token = get_token()
+    if not token or token not in SESSION_TOKENS:
+        raise PermissionError("Brak autoryzacji.")
+    return token
+
+
+@app.route("/<path:path>")
+def serve_static(path: str) -> Any:
+    if path not in ALLOWED_STATIC:
+        return jsonify({"error": "Nie znaleziono pliku."}), 404
+    target = Path(app.static_folder) / path
+    if target.is_file():
+        return send_from_directory(app.static_folder, path)
+    return jsonify({"error": "Nie znaleziono pliku."}), 404
+
+
+@app.route("/api/status", methods=["GET"])
+def api_status() -> Any:
+    data = load_store()
+    configured = bool(data.get("business") and data.get("password_hash"))
+    return jsonify({"configured": configured})
+
+
+@app.route("/api/setup", methods=["POST"])
+def api_setup() -> Any:
+    data = load_store()
+    if data.get("password_hash"):
+        return jsonify({"error": "Aplikacja zostala juz skonfigurowana."}), 400
+
     payload = request.get_json(force=True)
-    email = payload.get("email")
-    password = payload.get("password")
-    confirm = payload.get("confirm_password")
-    business_fields = [
+    required_fields = [
         "company_name",
         "owner_name",
         "address_line",
@@ -211,796 +279,112 @@ def api_register() -> Any:
         "city",
         "tax_id",
         "bank_account",
+        "password",
     ]
-    business_data: Dict[str, str] = {}
-
-    for field in business_fields:
-        value = (payload.get(field) or "").strip()
-        if not value:
-            return jsonify({"error": f"Pole {field} jest wymagane."}), 400
-        business_data[field] = value
-
-    if password != confirm:
-        return jsonify({"error": "Hasla musza byc identyczne."}), 400
-    if len(password or "") < PASSWORD_MIN_LENGTH:
-        return jsonify({"error": "Haslo jest za krotkie."}), 400
-
-    login_key, display_email = normalize_email(email)
-    password_hash = hash_password(password)
-
-    if DATABASE_AVAILABLE:
-        if fetch_one("SELECT 1 FROM accounts WHERE login = %s", (login_key,)):
-            return jsonify({"error": "Konto o podanym emailu juz istnieje."}), 400
-        account_id = create_account(login_key, display_email, password_hash)
-        update_business(account_id, business_data)
-        return jsonify({"message": "Konto zostalo utworzone."})
 
-    data = load_store()
-    accounts = data.setdefault("accounts", {})
-    if login_key in accounts:
-        return jsonify({"error": "Konto o podanym emailu juz istnieje."}), 400
-
-    accounts[login_key] = {
-        "login": login_key,
-        "email": display_email,
-        "password_hash": password_hash,
-        "business": business_data,
-        "invoices": [],
-        "logo": None,
-        "created_at": datetime.utcnow().isoformat(timespec="seconds"),
+    missing = [field for field in required_fields if not (payload.get(field) or "").strip()]
+    if missing:
+        return jsonify({"error": f"Brakuje pol: {', '.join(missing)}"}), 400
+
+    if len(payload["password"]) < 4:
+        return jsonify({"error": "Haslo musi miec co najmniej 4 znaki."}), 400
+
+    data["business"] = {
+        "company_name": payload["company_name"].strip(),
+        "owner_name": payload["owner_name"].strip(),
+        "address_line": payload["address_line"].strip(),
+        "postal_code": payload["postal_code"].strip(),
+        "city": payload["city"].strip(),
+        "tax_id": payload["tax_id"].strip(),
+        "bank_account": payload["bank_account"].strip(),
     }
+    data["password_hash"] = hash_password(payload["password"])
+    data.setdefault("invoices", [])
+
     save_store(data)
-    return jsonify({"message": "Konto zostalo utworzone."})
-
-
-@app.route("/api/login", methods=["POST"])
-def api_login() -> Any:
-    payload = request.get_json(force=True)
-    identifier = payload.get("identifier") or payload.get("email")
-    password = payload.get("password")
-    if not identifier or not password:
-        return jsonify({"error": "Podaj email/login i haslo."}), 400
-
-    login_key, _ = normalize_email(identifier)
-
-    if DATABASE_AVAILABLE:
-        row = fetch_one(
-            "SELECT id, password_hash FROM accounts WHERE login = %s",
-            (login_key,),
-        )
-        if not row or row["password_hash"] != hash_password(password):
-            return jsonify({"error": "Niepoprawne dane logowania."}), 401
-        token = uuid.uuid4().hex
-        SESSION_TOKENS[token] = {
-            "login_key": login_key,
-            "account_id": row["id"],
-            "expires_at": datetime.utcnow() + TOKEN_TTL,
-        }
-        return jsonify({"token": token, "login": login_key})
-
-    data = load_store()
-    accounts = data.get("accounts") or {}
-    login_key, account = find_account_identifier(accounts, login_key)
-    if not account or account.get("password_hash") != hash_password(password):
-        return jsonify({"error": "Niepoprawne dane logowania."}), 401
-    token = uuid.uuid4().hex
-    SESSION_TOKENS[token] = {
-        "login_key": login_key,
-        "expires_at": datetime.utcnow() + TOKEN_TTL,
-    }
-    return jsonify({"token": token, "login": account.get("login", login_key)})
-
-
-@app.route("/api/logout", methods=["POST"])
-def api_logout() -> Any:
-    token = request.headers.get("Authorization", "").replace("Bearer ", "")
-    SESSION_TOKENS.pop(token, None)
-    return jsonify({"message": "Wylogowano."})
-
-
-@app.route("/api/business", methods=["GET", "POST"])
-def api_business() -> Any:
-    try:
-        login_key = require_auth()
-    except PermissionError:
-        return jsonify({"error": "Brak autoryzacji."}), 401
-
-    data = load_store()
-    account = data.get("accounts", {}).get(login_key)
-    account_row = None
-    if DATABASE_AVAILABLE:
-        try:
-            account_row = get_account_row(login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-
-    if request.method == "GET":
-        if DATABASE_AVAILABLE:
-            profile = fetch_one(
-                """
-                SELECT company_name, owner_name, address_line, postal_code,
-                       city, tax_id, bank_account
-                FROM business_profiles
-                WHERE account_id = %s
-                """,
-                (account_row["id"],),
-            )
-            return jsonify({"business": profile})
-        if not account:
-            return jsonify({"business": None})
-        return jsonify({"business": account.get("business")})
-
-    payload = request.get_json(force=True)
-    required_fields = [
-        "company_name",
-        "owner_name",
-        "address_line",
-        "postal_code",
-        "city",
-        "tax_id",
-        "bank_account",
-    ]
-    for field in required_fields:
-        if not (payload.get(field) or "").strip():
-            return jsonify({"error": f"Pole {field} jest wymagane."}), 400
-
-    if DATABASE_AVAILABLE:
-        update_business(account_row["id"], payload)
-        return jsonify({"message": "Dane sprzedawcy zostaly zaktualizowane."})
-
-    if not account:
-        return jsonify({"error": "Nie znaleziono konta."}), 404
-    account["business"] = payload
-    save_store(data)
-    return jsonify({"message": "Dane sprzedawcy zostaly zaktualizowane."})
+    return jsonify({"message": "Dane zapisane. Mozesz sie zalogowac."})
 
 
-@app.route("/api/clients", methods=["GET"])
-def api_clients() -> Any:
-    try:
-        login_key = require_auth()
-    except PermissionError:
-        return jsonify({"error": "Brak autoryzacji."}), 401
+@app.route("/api/login", methods=["POST"])
+def api_login() -> Any:
+    payload = request.get_json(force=True)
+    password = (payload.get("password") or "").strip()
+    data = load_store()
 
-    if not DATABASE_AVAILABLE:
-        return jsonify({"clients": []})
+    if not data.get("password_hash"):
+        return jsonify({"error": "Aplikacja nie zostala skonfigurowana."}), 400
 
-    try:
-        account_row = get_account_row(login_key)
-    except KeyError:
-        return jsonify({"error": "Nie znaleziono konta."}), 404
+    if hash_password(password) != data["password_hash"]:
+        return jsonify({"error": "Nieprawidlowe haslo."}), 401
 
-    search_term = (request.args.get("q") or "").strip()
-    limit_param = request.args.get("limit", "10")
-    try:
-        limit_value = int(limit_param)
-    except ValueError:
-        limit_value = 10
-    limit_value = max(1, min(25, limit_value))
-    clients = search_clients(account_row["id"], search_term, limit_value)
-    return jsonify({"clients": clients})
-
-
-@app.route("/api/logo", methods=["GET", "POST", "DELETE"])
-def api_logo() -> Any:
-    try:
-        login_key = require_auth()
-    except PermissionError:
-        return jsonify({"error": "Brak autoryzacji."}), 401
-
-    account_row = None
-    account = None
-    data = None
-
-    if DATABASE_AVAILABLE:
-        try:
-            account_row = get_account_row(login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-    else:
-        data = load_store()
-        try:
-            account = get_account(data, login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-
-    if request.method == "GET":
-        if DATABASE_AVAILABLE:
-            logo_row = fetch_business_logo(account_row["id"])
-            if not logo_row:
-                return jsonify({"logo": None})
-            mime_type = logo_row["mime_type"]
-            encoded = logo_row["data"]
-            data_url = f"data:{mime_type};base64,{encoded}" if mime_type and encoded else None
-            return jsonify(
-                {
-                    "logo": {
-                        "filename": None,
-                        "mime_type": mime_type,
-                        "data": encoded,
-                        "data_url": data_url,
-                        "uploaded_at": None,
-                    }
-                }
-            )
-        logo = account.get("logo") if account else None
-        if not logo:
-            return jsonify({"logo": None})
-        encoded = logo.get("data")
-        mime_type = logo.get("mime_type")
-        data_url = None
-        if encoded and mime_type:
-            data_url = f"data:{mime_type};base64,{encoded}"
-        return jsonify(
-            {
-                "logo": {
-                    "filename": logo.get("filename"),
-                    "mime_type": mime_type,
-                    "data": encoded,
-                    "data_url": data_url,
-                    "uploaded_at": logo.get("uploaded_at"),
-                }
-            }
-        )
-
-    if request.method == "DELETE":
-        if DATABASE_AVAILABLE:
-            update_business_logo(account_row["id"], None, None)
-            return jsonify({"message": "Logo zostalo usuniete."})
-        if not account or data is None:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-        account["logo"] = None
-        save_store(data)
-        return jsonify({"message": "Logo zostalo usuniete."})
-
-    payload = request.get_json(force=True)
-    raw_content = (payload.get("content") or payload.get("data") or "").strip()
-    if not raw_content:
-        return jsonify({"error": "Brak danych logo."}), 400
-
-    provided_mime = (payload.get("mime_type") or "").strip()
-    filename = sanitize_filename(payload.get("filename"))
-
-    if raw_content.startswith("data:"):
-        try:
-            header, encoded_content = raw_content.split(",", 1)
-        except ValueError:
-            return jsonify({"error": "Niepoprawny format danych logo."}), 400
-        header = header.strip()
-        if ";base64" not in header:
-            return jsonify({"error": "Niepoprawny format danych logo (oczekiwano base64)."}), 400
-        mime_type = header.split(";")[0].replace("data:", "", 1) or provided_mime
-        base64_content = encoded_content.strip()
-    else:
-        mime_type = provided_mime
-        base64_content = raw_content
-
-    mime_type = (mime_type or "").lower()
-    if mime_type not in ALLOWED_LOGO_MIME_TYPES:
-        return jsonify({"error": "Dozwolone formaty logo to PNG lub JPG."}), 400
-
-    try:
-        logo_bytes = base64.b64decode(base64_content, validate=True)
-    except (ValueError, binascii.Error):
-        return jsonify({"error": "Nie udalo sie odczytac danych logo (base64)."}), 400
-
-    if len(logo_bytes) > MAX_LOGO_SIZE:
-        return jsonify({"error": f"Logo jest zbyt duze (maksymalnie {MAX_LOGO_SIZE // 1024} KB)."}), 400
-
-    encoded_logo = base64.b64encode(logo_bytes).decode("ascii")
-    stored_logo = {
-        "filename": filename,
-        "mime_type": mime_type,
-        "data": encoded_logo,
-        "uploaded_at": datetime.utcnow().isoformat(timespec="seconds"),
-    }
-
-    if DATABASE_AVAILABLE:
-        update_business_logo(account_row["id"], stored_logo["mime_type"], stored_logo["data"])
-        return jsonify({"logo": stored_logo})
-
-    account["logo"] = stored_logo
-    save_store(data)
-    return jsonify({"logo": stored_logo})
-
-def normalize_phone(phone: Optional[str]) -> Optional[str]:
-    if not phone:
-        return None
-    digits = re.sub(r"[^\d+]", "", phone)
-    return digits or None
-
-
-def validate_client(payload: Dict[str, Any]) -> Dict[str, str]:
-    client_payload = payload.get("client") or {}
-    client = {
-        "name": (client_payload.get("name") or payload.get("clientName") or "").strip(),
-        "tax_id": (client_payload.get("tax_id") or payload.get("clientTaxId") or "").strip(),
-        "address_line": (client_payload.get("address_line") or payload.get("clientAddress") or "").strip(),
-        "postal_code": (client_payload.get("postal_code") or payload.get("clientPostalCode") or "").strip(),
-        "city": (client_payload.get("city") or payload.get("clientCity") or "").strip(),
-        "phone": normalize_phone(client_payload.get("phone") or payload.get("clientPhone")),
-    }
-    return client
-
-
-def build_invoice(payload: Dict[str, Any], business: Dict[str, Any], client: Dict[str, str]) -> Dict[str, Any]:
-    now = datetime.now()
-    invoice_id = f"FV-{now.strftime('%Y%m%d-%H%M%S')}"
-    issued_at = now.strftime("%Y-%m-%d %H:%M")
-    sale_date = payload.get("sale_date") or payload.get("saleDate") or date.today().isoformat()
-    payment_term = int(payload.get("payment_term") or payload.get("paymentTerm") or 14)
-    items = payload.get("items") or []
-
-    normalized_items: List[Dict[str, Any]] = []
-    for item in items:
-        name = (item.get("name") or "").strip()
-        if not name:
-            raise ValueError("Nazwa pozycji nie moze byc pusta.")
-        quantity = _quantize(_decimal(item.get("quantity") or "0"))
-        if quantity <= Decimal("0"):
-            raise ValueError("Ilosc musi byc dodatnia.")
-        unit = item.get("unit") or DEFAULT_UNIT
-        vat_code = str(item.get("vat_code") or item.get("vat") or item.get("vatCode") or "23")
-        if vat_code not in VAT_RATES:
-            raise ValueError("Niepoprawna stawka VAT.")
-        unit_price_raw = item.get("unit_price_gross")
-        if unit_price_raw in (None, ""):
-            unit_price_raw = item.get("unitPrice") or item.get("unit_price") or item.get("price")
-        unit_price_gross = _quantize(_decimal(unit_price_raw or "0"))
-        if unit_price_gross <= Decimal("0"):
-            raise ValueError("Cena musi byc dodatnia.")
-        vat_rate = VAT_RATES[vat_code]
-        if vat_rate is None:
-            unit_price_net = unit_price_gross
-            vat_amount = Decimal("0.00")
-        else:
-            unit_price_net = _quantize(unit_price_gross / (Decimal("1.0") + vat_rate))
-            vat_amount = _quantize(unit_price_gross - unit_price_net)
-        net_total = _quantize(unit_price_net * quantity)
-        vat_total = _quantize(vat_amount * quantity)
-        gross_total = _quantize(unit_price_gross * quantity)
-        normalized_items.append(
-            {
-                "name": name,
-                "quantity": str(quantity),
-                "unit": unit,
-                "vat_code": vat_code,
-                "vat_label": item.get("vatLabel") or vat_code,
-                "unit_price_net": str(unit_price_net),
-                "unit_price_gross": str(unit_price_gross),
-                "net_total": str(net_total),
-                "vat_amount": str(vat_amount),
-                "gross_total": str(gross_total),
-            }
-        )
-
-    totals = {"net": Decimal("0"), "vat": Decimal("0"), "gross": Decimal("0")}
-    summary: Dict[str, Dict[str, Decimal]] = {}
-    for item in normalized_items:
-        totals["net"] += Decimal(item["net_total"])
-        totals["vat"] += Decimal(item["vat_amount"])
-        totals["gross"] += Decimal(item["gross_total"])
-        label = item["vat_label"]
-        summary.setdefault(label, {"net_total": Decimal("0"), "vat_total": Decimal("0"), "gross_total": Decimal("0")})
-        summary[label]["net_total"] += Decimal(item["net_total"])
-        summary[label]["vat_total"] += Decimal(item["vat_amount"])
-        summary[label]["gross_total"] += Decimal(item["gross_total"])
-
-    totals = {key: str(_quantize(value)) for key, value in totals.items()}
-    summary_list = [
-        {
-            "vat_label": label,
-            "net_total": str(_quantize(values["net_total"])),
-            "vat_total": str(_quantize(values["vat_total"])),
-            "gross_total": str(_quantize(values["gross_total"])),
-        }
-        for label, values in summary.items()
-    ]
-
-    exemption_note = (payload.get("exemption_note") or payload.get("exemptionNote") or "").strip()
-
-    return {
-        "invoice_id": invoice_id,
-        "issued_at": issued_at,
-        "sale_date": sale_date,
-        "payment_term": payment_term,
-        "items": normalized_items,
-        "summary": summary_list,
-        "totals": totals,
-        "client": client,
-        "business": business,
-        "exemption_note": exemption_note,
-    }
-
-
-@app.route("/api/invoices", methods=["GET", "POST"])
-def api_invoices() -> Any:
+    token = create_token()
+    return jsonify({"token": token})
+
+
+@app.route("/api/business", methods=["GET", "PUT"])
+def api_business() -> Any:
     try:
-        login_key = require_auth()
+        require_auth()
     except PermissionError:
         return jsonify({"error": "Brak autoryzacji."}), 401
 
+    data = load_store()
     if request.method == "GET":
-        if DATABASE_AVAILABLE:
-            try:
-                account_row = get_account_row(login_key)
-            except KeyError:
-                return jsonify({"error": "Nie znaleziono konta."}), 404
-            invoice_rows = fetch_all(
-                """
-                SELECT i.id,
-                       i.invoice_number,
-                       i.issued_at,
-                       i.sale_date,
-                       i.payment_term_days,
-                       i.exemption_note,
-                       i.total_net,
-                       i.total_vat,
-                       i.total_gross,
-                       c.name AS client_name,
-                       c.address_line AS client_address,
-                       c.postal_code AS client_postal_code,
-                       c.city AS client_city,
-                       c.tax_id AS client_tax_id,
-                       c.phone AS client_phone
-                FROM invoices AS i
-                LEFT JOIN clients AS c ON c.id = i.client_id
-                WHERE i.account_id = %s
-                ORDER BY i.issued_at DESC
-                LIMIT %s
-                """,
-                (account_row["id"], INVOICE_HISTORY_LIMIT),
-            )
-            if not invoice_rows:
-                return jsonify({"invoices": []})
-
-            invoice_ids = [row["id"] for row in invoice_rows]
-            items_map: Dict[int, List[Dict[str, Any]]] = {row_id: [] for row_id in invoice_ids}
-            summary_map: Dict[int, List[Dict[str, str]]] = {row_id: [] for row_id in invoice_ids}
-
-            if invoice_ids:
-                item_rows = fetch_all(
-                    """
-                    SELECT invoice_id, line_no, name, quantity, unit,
-                           vat_code, vat_label, unit_price_net,
-                           unit_price_gross, net_total, vat_amount, gross_total
-                    FROM invoice_items
-                    WHERE invoice_id = ANY(%s)
-                    ORDER BY line_no
-                    """,
-                    (invoice_ids,),
-                )
-                for item in item_rows:
-                    items_map.setdefault(item["invoice_id"], []).append(
-                        {
-                            "name": item["name"],
-                            "quantity": _format_decimal_str(item.get("quantity"), "0.00"),
-                            "unit": item.get("unit") or DEFAULT_UNIT,
-                            "vat_code": item.get("vat_code"),
-                            "vat_label": item.get("vat_label") or item.get("vat_code"),
-                            "unit_price_net": _format_decimal_str(item.get("unit_price_net")),
-                            "unit_price_gross": _format_decimal_str(item.get("unit_price_gross")),
-                            "net_total": _format_decimal_str(item.get("net_total")),
-                            "vat_amount": _format_decimal_str(item.get("vat_amount")),
-                            "gross_total": _format_decimal_str(item.get("gross_total")),
-                        }
-                    )
-
-                summary_rows = fetch_all(
-                    """
-                    SELECT invoice_id, vat_label, net_total, vat_total, gross_total
-                    FROM invoice_vat_summary
-                    WHERE invoice_id = ANY(%s)
-                    ORDER BY vat_label
-                    """,
-                    (invoice_ids,),
-                )
-                for entry in summary_rows:
-                    summary_map.setdefault(entry["invoice_id"], []).append(
-                        {
-                            "vat_label": entry.get("vat_label"),
-                            "net_total": _format_decimal_str(entry.get("net_total")),
-                            "vat_total": _format_decimal_str(entry.get("vat_total")),
-                            "gross_total": _format_decimal_str(entry.get("gross_total")),
-                        }
-                    )
-
-            business_profile = get_business_profile(account_row["id"])
-            invoices: List[Dict[str, Any]] = []
-            for row in invoice_rows:
-                issued_at_value = row.get("issued_at")
-                sale_date_value = row.get("sale_date")
-                if isinstance(issued_at_value, datetime):
-                    issued_at = issued_at_value.strftime("%Y-%m-%d %H:%M")
-                else:
-                    issued_at = issued_at_value
-                if hasattr(sale_date_value, "isoformat"):
-                    sale_date = sale_date_value.isoformat()
-                else:
-                    sale_date = sale_date_value
-                client = None
-                if row.get("client_name"):
-                    client = {
-                        "name": row.get("client_name"),
-                        "address_line": row.get("client_address"),
-                        "postal_code": row.get("client_postal_code"),
-                        "city": row.get("client_city"),
-                        "tax_id": row.get("client_tax_id"),
-                        "phone": row.get("client_phone"),
-                    }
-                invoices.append(
-                    {
-                        "invoice_id": row.get("invoice_number"),
-                        "issued_at": issued_at,
-                        "sale_date": sale_date,
-                        "payment_term": row.get("payment_term_days"),
-                        "exemption_note": row.get("exemption_note"),
-                        "items": items_map.get(row["id"], []),
-                        "summary": summary_map.get(row["id"], []),
-                        "totals": {
-                            "net": _format_decimal_str(row.get("total_net")),
-                            "vat": _format_decimal_str(row.get("total_vat")),
-                            "gross": _format_decimal_str(row.get("total_gross")),
-                        },
-                        "client": client,
-                        "business": business_profile,
-                    }
-                )
-            return jsonify({"invoices": invoices})
-
-        data = load_store()
-        try:
-            account = get_account(data, login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-        invoices = account.get("invoices", [])[:INVOICE_HISTORY_LIMIT]
-        return jsonify({"invoices": invoices})
+        ensure_configured(data)
+        return jsonify({"business": data["business"]})
 
     payload = request.get_json(force=True)
+    current = data.get("business") or {}
+    updated = {
+        "company_name": (payload.get("company_name") or current.get("company_name") or "").strip(),
+        "owner_name": (payload.get("owner_name") or current.get("owner_name") or "").strip(),
+        "address_line": (payload.get("address_line") or current.get("address_line") or "").strip(),
+        "postal_code": (payload.get("postal_code") or current.get("postal_code") or "").strip(),
+        "city": (payload.get("city") or current.get("city") or "").strip(),
+        "tax_id": (payload.get("tax_id") or current.get("tax_id") or "").strip(),
+        "bank_account": (payload.get("bank_account") or current.get("bank_account") or "").strip(),
+    }
 
-    if DATABASE_AVAILABLE:
-        try:
-            account_row = get_account_row(login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-        business = get_business_profile(account_row["id"])
-        if not business:
-            return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400
-
-        client = validate_client(payload)
-        try:
-            invoice = build_invoice(payload, business, client)
-        except ValueError as error:
-            return jsonify({"error": str(error)}), 400
-
-        client_id = upsert_client(
-            account_row["id"],
-            {
-                "name": client["name"],
-                "address_line": client["address_line"],
-                "postal_code": client["postal_code"],
-                "city": client["city"],
-                "tax_id": client["tax_id"],
-                "phone": client.get("phone"),
-            },
-        )
-        insert_invoice(account_row["id"], client_id, invoice)
-        return jsonify({"message": "Faktura zostala zapisana.", "invoice": invoice})
-
-    data = load_store()
-    try:
-        account = get_account(data, login_key)
-    except KeyError:
-        return jsonify({"error": "Nie znaleziono konta."}), 404
-
-    business = account.get("business")
-    if not business:
-        return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400
-
-    client = validate_client(payload)
-    try:
-        invoice = build_invoice(payload, business, client)
-    except ValueError as error:
-        return jsonify({"error": str(error)}), 400
+    missing = [field for field, value in updated.items() if not value]
+    if missing:
+        return jsonify({"error": f"Wypelnij wszystkie pola: {', '.join(missing)}"}), 400
 
-    invoices = account.setdefault("invoices", [])
-    invoices.insert(0, invoice)
-    account["invoices"] = invoices[:INVOICE_HISTORY_LIMIT]
+    data["business"] = updated
     save_store(data)
-    return jsonify({"message": "Faktura zostala zapisana.", "invoice": invoice})
+    return jsonify({"business": updated})
 
 
-@app.route("/api/invoices/<invoice_id>", methods=["PUT", "DELETE"])
-def api_invoice_detail(invoice_id: str) -> Any:
+@app.route("/api/invoices", methods=["POST", "GET"])
+def api_invoices() -> Any:
     try:
-        login_key = require_auth()
+        require_auth()
     except PermissionError:
         return jsonify({"error": "Brak autoryzacji."}), 401
 
-    if DATABASE_AVAILABLE:
-        try:
-            account_row = get_account_row(login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-
-        invoice_row = fetch_one(
-            """
-            SELECT id, issued_at
-            FROM invoices
-            WHERE account_id = %s AND invoice_number = %s
-            """,
-            (account_row["id"], invoice_id),
-        )
-        if not invoice_row:
-            return jsonify({"error": "Nie znaleziono faktury."}), 404
-
-        if request.method == "DELETE":
-            execute("DELETE FROM invoice_items WHERE invoice_id = %s", (invoice_row["id"],))
-            execute("DELETE FROM invoice_vat_summary WHERE invoice_id = %s", (invoice_row["id"],))
-            execute("DELETE FROM invoices WHERE id = %s", (invoice_row["id"],))
-            return jsonify({"message": "Faktura zostala usunieta."})
-
-        payload = request.get_json(force=True)
-        business = get_business_profile(account_row["id"])
-        if not business:
-            return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400
-
-        client = validate_client(payload)
-        try:
-            invoice = build_invoice(payload, business, client)
-        except ValueError as error:
-            return jsonify({"error": str(error)}), 400
-
-        invoice["invoice_id"] = invoice_id
-        existing_issued_at = invoice_row.get("issued_at")
-        if isinstance(existing_issued_at, datetime):
-            invoice["issued_at"] = existing_issued_at.strftime("%Y-%m-%d %H:%M")
-        elif existing_issued_at:
-            invoice["issued_at"] = str(existing_issued_at)
-
-        client_id = upsert_client(
-            account_row["id"],
-            {
-                "name": client["name"],
-                "address_line": client["address_line"],
-                "postal_code": client["postal_code"],
-                "city": client["city"],
-                "tax_id": client["tax_id"],
-                "phone": client.get("phone"),
-            },
-        )
-
-        execute("DELETE FROM invoice_items WHERE invoice_id = %s", (invoice_row["id"],))
-        execute("DELETE FROM invoice_vat_summary WHERE invoice_id = %s", (invoice_row["id"],))
-        execute("DELETE FROM invoices WHERE id = %s", (invoice_row["id"],))
-        insert_invoice(account_row["id"], client_id, invoice)
-        return jsonify({"message": "Faktura zostala zaktualizowana.", "invoice": invoice})
-
     data = load_store()
-    try:
-        account = get_account(data, login_key)
-    except KeyError:
-        return jsonify({"error": "Nie znaleziono konta."}), 404
-
-    invoices = account.get("invoices", [])
-    invoice_index = next(
-        (idx for idx, entry in enumerate(invoices) if entry.get("invoice_id") == invoice_id),
-        None,
-    )
-    if invoice_index is None:
-        return jsonify({"error": "Nie znaleziono faktury."}), 404
-
-    if request.method == "DELETE":
-        invoices.pop(invoice_index)
-        save_store(data)
-        return jsonify({"message": "Faktura zostala usunieta."})
+    ensure_configured(data)
 
-    payload = request.get_json(force=True)
-    business = account.get("business")
-    if not business:
-        return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400
+    if request.method == "GET":
+        return jsonify({"invoices": data.get("invoices", [])})
 
-    client = validate_client(payload)
+    payload = request.get_json(force=True)
     try:
-        invoice = build_invoice(payload, business, client)
+        invoice = compute_invoice(payload, data["business"])
     except ValueError as error:
         return jsonify({"error": str(error)}), 400
 
-    invoice["invoice_id"] = invoice_id
-    existing_invoice = invoices[invoice_index]
-    if existing_invoice.get("issued_at"):
-        invoice["issued_at"] = existing_invoice.get("issued_at")
-    invoices[invoice_index] = invoice
-    save_store(data)
-    return jsonify({"message": "Faktura zostala zaktualizowana.", "invoice": invoice})
-
-
-@app.route("/api/invoices/summary", methods=["GET"])
-def api_invoice_summary() -> Any:
-    try:
-        login_key = require_auth()
-    except PermissionError:
-        return jsonify({"error": "Brak autoryzacji."}), 401
+    invoices = data.setdefault("invoices", [])
+    invoices.append(invoice)
+    if len(invoices) > INVOICE_HISTORY_LIMIT:
+        data["invoices"] = invoices[-INVOICE_HISTORY_LIMIT:]
 
-    now = datetime.utcnow()
-    last_month_start = now - timedelta(days=30)
-    quarter_first_month = ((now.month - 1) // 3) * 3 + 1
-    quarter_start = now.replace(month=quarter_first_month, day=1, hour=0, minute=0, second=0, microsecond=0)
-    year_start = now.replace(month=1, day=1, hour=0, minute=0, second=0, microsecond=0)
-
-    def normalize_issued_at(value: Any) -> Optional[datetime]:
-        if isinstance(value, datetime):
-            tzinfo = value.tzinfo
-            if tzinfo is not None and tzinfo.utcoffset(value) is not None:
-                return value.astimezone(timezone.utc).replace(tzinfo=None)
-            return value
-        if isinstance(value, str):
-            candidate = value.strip()
-            if not candidate:
-                return None
-            for fmt in ("%Y-%m-%d %H:%M", "%Y-%m-%dT%H:%M:%S", "%Y-%m-%d"):
-                try:
-                    return datetime.strptime(candidate, fmt)
-                except ValueError:
-                    continue
-        return None
+    save_store(data)
+    return jsonify({"invoice": invoice})
 
-    def aggregate_from_rows(rows: List[Dict[str, Any]], start: datetime) -> Dict[str, Any]:
-        count = 0
-        gross_total = Decimal("0.00")
-        for row in rows:
-            issued_dt = normalize_issued_at(row.get("issued_at"))
-            if issued_dt is None or issued_dt < start:
-                continue
-            try:
-                gross_total += _decimal(row.get("total_gross") or "0")
-            except ValueError:
-                continue
-            count += 1
-        return {"count": count, "gross_total": str(_quantize(gross_total))}
-
-    if DATABASE_AVAILABLE:
-        try:
-            account_row = get_account_row(login_key)
-        except KeyError:
-            return jsonify({"error": "Nie znaleziono konta."}), 404
-        rows = fetch_all(
-            """
-            SELECT issued_at, total_gross
-            FROM invoices
-            WHERE account_id = %s
-            """,
-            (account_row["id"],),
-        )
-        summary = {
-            "last_month": aggregate_from_rows(rows, last_month_start),
-            "quarter": aggregate_from_rows(rows, quarter_start),
-            "year": aggregate_from_rows(rows, year_start),
-        }
-        return jsonify({"summary": summary})
 
-    data = load_store()
-    try:
-        account = get_account(data, login_key)
-    except KeyError:
-        return jsonify({"error": "Nie znaleziono konta."}), 404
-    invoices = account.get("invoices", [])
-    rows = [
-        {
-            "issued_at": invoice.get("issued_at"),
-            "total_gross": (invoice.get("totals") or {}).get("gross", "0"),
-        }
-        for invoice in invoices
-    ]
+if __name__ == "__main__":
+    port = int(os.environ.get("PORT", "7860"))
+    app.run(host="0.0.0.0", port=port, debug=True)
 
-    summary = {
-        "last_month": aggregate_from_rows(rows, last_month_start),
-        "quarter": aggregate_from_rows(rows, quarter_start),
-        "year": aggregate_from_rows(rows, year_start),
-    }
-    return jsonify({"summary": summary})
-
-
-if __name__ == "__main__":
-    port = int(os.environ.get("PORT", "5000"))
-    app.run(host="0.0.0.0", port=port, debug=True)
+    DATA_DIR = Path(os.environ.get("DATA_DIR", APP_ROOT))
+DATA_FILE = DATA_DIR / "web_invoice_store.json"

static/css/styles.css

@@ -0,0 +1,365 @@
+:root {
+  --bg: #f5f5f5;
+  --panel-bg: #ffffff;
+  --text: #202124;
+  --muted: #5f6368;
+  --accent: #1a73e8;
+  --danger: #c5221f;
+  --border: #dadce0;
+  --radius: 10px;
+  --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
+  font-family: "Segoe UI", Tahoma, sans-serif;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  background: linear-gradient(180deg, #f7f9fc 0%, #eef1f6 100%);
+  color: var(--text);
+}
+
+.container {
+  max-width: 980px;
+  margin: 0 auto;
+  padding: 40px 20px 64px;
+}
+
+h1 {
+  text-align: center;
+  font-size: 32px;
+  margin-bottom: 32px;
+}
+
+.panel {
+  background: var(--panel-bg);
+  border-radius: var(--radius);
+  box-shadow: var(--shadow);
+  padding: 28px 32px;
+  margin-bottom: 32px;
+  border: 1px solid rgba(32, 33, 36, 0.08);
+}
+
+.panel h2 {
+  margin-top: 0;
+}
+
+.hidden {
+  display: none;
+}
+
+.form {
+  display: grid;
+  gap: 20px;
+}
+
+.field-grid {
+  display: grid;
+  gap: 18px 24px;
+  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
+}
+
+label {
+  display: grid;
+  gap: 8px;
+  font-weight: 600;
+  font-size: 15px;
+}
+
+input,
+textarea,
+select {
+  padding: 12px 14px;
+  border-radius: 8px;
+  border: 1px solid var(--border);
+  font-size: 15px;
+  background: #fbfbff;
+}
+
+input:focus,
+textarea:focus,
+select:focus {
+  outline: 2px solid rgba(26, 115, 232, 0.35);
+  outline-offset: 1px;
+  border-color: var(--accent);
+  background: #ffffff;
+}
+
+textarea {
+  resize: vertical;
+  min-height: 96px;
+}
+
+button {
+  padding: 12px 20px;
+  border-radius: 8px;
+  border: none;
+  font-size: 15px;
+  font-weight: 600;
+  background: var(--accent);
+  color: white;
+  cursor: pointer;
+  transition: background 0.2s ease;
+}
+
+button:hover {
+  background: #0f5ec4;
+}
+
+button:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.link-button {
+  background: none;
+  color: var(--accent);
+  padding: 0;
+}
+
+.link-button:hover {
+  color: #0f5ec4;
+  background: none;
+}
+
+.hint {
+  color: var(--muted);
+  font-size: 13px;
+  margin: 0;
+}
+
+.feedback {
+  color: var(--muted);
+  min-height: 20px;
+  font-size: 14px;
+}
+
+.feedback.error {
+  color: var(--danger);
+}
+
+.feedback.success {
+  color: #188038;
+}
+
+.invoice-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 24px;
+}
+
+.business-section {
+  border: 1px solid rgba(32, 33, 36, 0.08);
+  border-radius: var(--radius);
+  padding: 20px 24px;
+  background: #fbfcff;
+  margin-bottom: 24px;
+}
+
+.business-section-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 12px;
+}
+
+.business-display {
+  display: grid;
+  gap: 6px;
+  font-size: 15px;
+  line-height: 1.4;
+}
+
+.business-display strong {
+  font-weight: 600;
+}
+
+.form-actions {
+  display: flex;
+  align-items: center;
+  gap: 16px;
+}
+
+.items-section {
+  border: 1px solid rgba(32, 33, 36, 0.08);
+  border-radius: var(--radius);
+  padding: 20px 24px;
+  background: #ffffff;
+  display: grid;
+  gap: 18px;
+}
+
+.items-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+}
+
+.items-table-wrapper {
+  overflow-x: auto;
+}
+
+.items-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 14px;
+}
+
+.items-table th,
+.items-table td {
+  border: 1px solid var(--border);
+  padding: 10px 12px;
+  text-align: left;
+}
+
+.items-table th {
+  background: #f1f3f7;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.02em;
+}
+
+.items-table input,
+.items-table select {
+  width: 100%;
+  padding: 8px 10px;
+  border-radius: 6px;
+  border: 1px solid var(--border);
+  background: #ffffff;
+}
+
+.items-table .remove-item {
+  color: var(--danger);
+  background: none;
+  padding: 0;
+}
+
+.items-table .remove-item:hover {
+  text-decoration: underline;
+}
+
+.totals {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 16px;
+  font-weight: 600;
+  margin-top: 8px;
+  padding: 12px 16px;
+  border-radius: 8px;
+  background: #f7f9ff;
+}
+
+.rate-summary {
+  display: grid;
+  gap: 10px;
+  margin-top: 8px;
+}
+
+.rate-summary-item {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 12px;
+  font-weight: 600;
+  padding: 8px 12px;
+  border: 1px dashed rgba(26, 115, 232, 0.25);
+  border-radius: 6px;
+  background: #ffffff;
+}
+
+.invoice-preview {
+  display: grid;
+  gap: 24px;
+}
+
+.invoice-preview-meta {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 24px;
+  font-size: 14px;
+}
+
+.invoice-preview-meta span {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+}
+
+.invoice-preview-header {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 24px;
+}
+
+.invoice-preview-card {
+  flex: 1 1 280px;
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  padding: 16px 20px;
+  background: #f9fafc;
+}
+
+.invoice-preview-card h4 {
+  margin: 0 0 12px;
+  font-size: 14px;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+}
+
+.invoice-preview-card p {
+  margin: 4px 0;
+  font-size: 14px;
+}
+
+.invoice-preview table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 14px;
+}
+
+.invoice-preview th,
+.invoice-preview td {
+  border: 1px solid var(--border);
+  padding: 10px 12px;
+  text-align: left;
+}
+
+.invoice-preview th {
+  background: #f1f3f7;
+  font-weight: 600;
+}
+
+.invoice-preview-summary {
+  display: flex;
+  justify-content: flex-end;
+  flex-wrap: wrap;
+  gap: 16px;
+  font-weight: 600;
+  font-size: 15px;
+}
+
+.invoice-preview-note {
+  padding: 12px 16px;
+  border-left: 3px solid var(--accent);
+  background: #f4f8ff;
+  font-size: 14px;
+}
+
+@media (max-width: 640px) {
+  .panel {
+    padding: 20px;
+  }
+
+  .invoice-header {
+    flex-direction: column;
+    gap: 12px;
+    align-items: flex-start;
+  }
+
+  .business-section,
+  .items-section {
+    padding: 16px;
+  }
+}

static/js/main.js

@@ -0,0 +1,984 @@
+const VAT_OPTIONS = [
+  { value: "23", label: "23%" },
+  { value: "8", label: "8%" },
+  { value: "5", label: "5%" },
+  { value: "0", label: "0% (ZW)" },
+  { value: "ZW", label: "ZW - zwolnione" },
+  { value: "NP", label: "NP - poza zakresem" },
+];
+
+const VAT_RATE_VALUES = {
+  "23": 0.23,
+  "8": 0.08,
+  "5": 0.05,
+  "0": 0,
+  ZW: 0,
+  NP: 0,
+};
+
+const setupSection = document.getElementById("setup-section");
+const loginSection = document.getElementById("login-section");
+const appSection = document.getElementById("app-section");
+
+const setupForm = document.getElementById("setup-form");
+const loginForm = document.getElementById("login-form");
+const invoiceForm = document.getElementById("invoice-form");
+const businessForm = document.getElementById("business-form");
+
+const setupFeedback = document.getElementById("setup-feedback");
+const loginFeedback = document.getElementById("login-feedback");
+const businessFeedback = document.getElementById("business-feedback");
+
+const businessDisplay = document.getElementById("business-display");
+const toggleBusinessFormButton = document.getElementById("toggle-business-form");
+const cancelBusinessUpdateButton = document.getElementById("cancel-business-update");
+
+const itemsBody = document.getElementById("items-body");
+const addItemButton = document.getElementById("add-item-button");
+
+const totalNetLabel = document.getElementById("total-net");
+const totalVatLabel = document.getElementById("total-vat");
+const totalGrossLabel = document.getElementById("total-gross");
+const rateSummaryContainer = document.getElementById("rate-summary");
+
+const exemptionNoteWrapper = document.getElementById("exemption-note-wrapper");
+const exemptionNoteInput = document.getElementById("exemption-note");
+
+const invoiceResult = document.getElementById("invoice-result");
+const invoiceOutput = document.getElementById("invoice-output");
+const downloadButton = document.getElementById("download-button");
+const logoutButton = document.getElementById("logout-button");
+
+let authToken = sessionStorage.getItem("invoiceAuthToken") || null;
+let currentBusiness = null;
+let lastInvoice = null;
+let pdfFontPromise = null;
+let pdfFontBase64 = null;
+
+function setState(state) {
+  setupSection.classList.add("hidden");
+  loginSection.classList.add("hidden");
+  appSection.classList.add("hidden");
+
+  if (state === "setup") {
+    setupSection.classList.remove("hidden");
+  } else if (state === "login") {
+    loginSection.classList.remove("hidden");
+  } else if (state === "app") {
+    appSection.classList.remove("hidden");
+  }
+}
+
+function clearFeedback(element) {
+  element.textContent = "";
+  element.classList.remove("error", "success");
+}
+
+function showFeedback(element, message, type = "error") {
+  element.textContent = message;
+  element.classList.remove("error", "success");
+  if (type) {
+    element.classList.add(type);
+  }
+}
+
+function parseNumber(value) {
+  if (typeof value === "number") {
+    return Number.isFinite(value) ? value : 0;
+  }
+  if (!value) {
+    return 0;
+  }
+  const normalized = value.toString().replace(",", ".");
+  const parsed = Number.parseFloat(normalized);
+  return Number.isFinite(parsed) ? parsed : 0;
+}
+
+function formatCurrency(value) {
+  const number = parseNumber(value);
+  return `${number.toFixed(2)} PLN`;
+}
+
+function vatLabelFromCode(code) {
+  if (code === "ZW" || code === "0") {
+    return "ZW";
+  }
+  if (code === "NP") {
+    return "NP";
+  }
+  return `${code}%`;
+}
+
+function requiresExemption(code) {
+  return code === "ZW" || code === "0";
+}
+
+async function apiRequest(path, { method = "GET", body, headers = {} } = {}, requireAuth = false) {
+  const options = {
+    method,
+    headers: {
+      "Content-Type": "application/json",
+      ...headers,
+    },
+  };
+
+  if (body !== undefined) {
+    options.body = JSON.stringify(body);
+  }
+
+  if (requireAuth) {
+    if (!authToken) {
+      throw new Error("Brak tokenu autoryzacyjnego.");
+    }
+    options.headers.Authorization = `Bearer ${authToken}`;
+  }
+
+  const response = await fetch(path, options);
+  const isJson = response.headers.get("content-type")?.includes("application/json");
+  const data = isJson ? await response.json() : {};
+
+  if (response.status === 401) {
+    authToken = null;
+    sessionStorage.removeItem("invoiceAuthToken");
+    setState("login");
+    throw new Error(data.error || "Sesja wygasla. Zaloguj sie ponownie.");
+  }
+
+  if (!response.ok) {
+    throw new Error(data.error || "Wystapil blad podczas komunikacji z serwerem.");
+  }
+
+  return data;
+}
+
+function renderBusinessDisplay(business) {
+  if (!business) {
+    businessDisplay.textContent = "Brak zapisanych danych firmy.";
+    return;
+  }
+
+  businessDisplay.innerHTML = `
+    <p><strong>${business.company_name}</strong></p>
+    <p>${business.owner_name}</p>
+    <p>${business.address_line}</p>
+    <p>${business.postal_code} ${business.city}</p>
+    <p>NIP: ${business.tax_id}</p>
+    <p>Konto: ${business.bank_account}</p>
+  `;
+}
+
+function fillBusinessForm(business) {
+  if (!business) {
+    return;
+  }
+  businessForm.elements.company_name.value = business.company_name || "";
+  businessForm.elements.owner_name.value = business.owner_name || "";
+  businessForm.elements.address_line.value = business.address_line || "";
+  businessForm.elements.postal_code.value = business.postal_code || "";
+  businessForm.elements.city.value = business.city || "";
+  businessForm.elements.tax_id.value = business.tax_id || "";
+  businessForm.elements.bank_account.value = business.bank_account || "";
+}
+
+function vatSelectElement(initialValue = "23") {
+  const select = document.createElement("select");
+  select.className = "item-vat";
+  VAT_OPTIONS.forEach((option) => {
+    const element = document.createElement("option");
+    element.value = option.value;
+    element.textContent = option.label;
+    select.appendChild(element);
+  });
+  select.value = VAT_OPTIONS.some((option) => option.value === initialValue) ? initialValue : "23";
+  return select;
+}
+
+function createItemRow(initialValues = {}) {
+  const row = document.createElement("tr");
+
+  const nameCell = document.createElement("td");
+  const nameInput = document.createElement("input");
+  nameInput.type = "text";
+  nameInput.className = "item-name";
+  nameInput.placeholder = "Nazwa towaru lub uslugi";
+  if (initialValues.name) {
+    nameInput.value = initialValues.name;
+  }
+  nameCell.appendChild(nameInput);
+
+  const quantityCell = document.createElement("td");
+  const quantityInput = document.createElement("input");
+  quantityInput.type = "number";
+  quantityInput.className = "item-quantity";
+  quantityInput.min = "0.01";
+  quantityInput.step = "0.01";
+  quantityInput.value = initialValues.quantity ?? "1";
+  quantityCell.appendChild(quantityInput);
+
+  const unitGrossCell = document.createElement("td");
+  const unitGrossInput = document.createElement("input");
+  unitGrossInput.type = "number";
+  unitGrossInput.className = "item-gross";
+  unitGrossInput.min = "0.01";
+  unitGrossInput.step = "0.01";
+  unitGrossInput.placeholder = "Brutto";
+  if (initialValues.unit_price_gross) {
+    unitGrossInput.value = initialValues.unit_price_gross;
+  }
+  unitGrossCell.appendChild(unitGrossInput);
+
+  const vatCell = document.createElement("td");
+  const vatSelect = vatSelectElement(initialValues.vat_code);
+  vatCell.appendChild(vatSelect);
+
+  const totalCell = document.createElement("td");
+  totalCell.className = "item-total";
+  totalCell.textContent = "0.00 PLN";
+
+  const actionsCell = document.createElement("td");
+  const removeButton = document.createElement("button");
+  removeButton.type = "button";
+  removeButton.className = "remove-item";
+  removeButton.textContent = "Usun";
+  actionsCell.appendChild(removeButton);
+
+  row.appendChild(nameCell);
+  row.appendChild(quantityCell);
+  row.appendChild(unitGrossCell);
+  row.appendChild(vatCell);
+  row.appendChild(totalCell);
+  row.appendChild(actionsCell);
+
+  const handleChange = () => updateTotals();
+  nameInput.addEventListener("input", handleChange);
+  quantityInput.addEventListener("input", handleChange);
+  unitGrossInput.addEventListener("input", handleChange);
+  vatSelect.addEventListener("change", handleChange);
+
+  removeButton.addEventListener("click", () => {
+    if (itemsBody.children.length === 1) {
+      nameInput.value = "";
+      quantityInput.value = "1";
+      unitGrossInput.value = "";
+      vatSelect.value = "23";
+      updateTotals();
+      return;
+    }
+    row.remove();
+    updateTotals();
+  });
+
+  itemsBody.appendChild(row);
+  updateTotals();
+}
+
+function calculateRowTotals(row) {
+  const name = row.querySelector(".item-name")?.value.trim() ?? "";
+  const quantity = parseNumber(row.querySelector(".item-quantity")?.value);
+  const unitGross = parseNumber(row.querySelector(".item-gross")?.value);
+  const vatCode = row.querySelector(".item-vat")?.value ?? "23";
+  const rate = VAT_RATE_VALUES[vatCode] ?? 0;
+
+  const hasValues = name || quantity > 0 || unitGross > 0;
+  if (!hasValues) {
+    return {
+      valid: false,
+      vatCode,
+      vatLabel: vatLabelFromCode(vatCode),
+      requiresExemption: requiresExemption(vatCode),
+      quantity,
+      unitGross,
+      unitNet: 0,
+      netTotal: 0,
+      vatAmount: 0,
+      grossTotal: 0,
+    };
+  }
+
+  if (quantity <= 0 || unitGross <= 0) {
+    return {
+      valid: false,
+      vatCode,
+      vatLabel: vatLabelFromCode(vatCode),
+      requiresExemption: requiresExemption(vatCode),
+      quantity,
+      unitGross,
+      unitNet: 0,
+      netTotal: 0,
+      vatAmount: 0,
+      grossTotal: quantity * unitGross,
+    };
+  }
+
+  const grossTotal = quantity * unitGross;
+  const netTotal = rate > 0 ? grossTotal / (1 + rate) : grossTotal;
+  const vatAmount = grossTotal - netTotal;
+  const unitNet = netTotal / quantity;
+
+  return {
+    valid: true,
+    vatCode,
+    vatLabel: vatLabelFromCode(vatCode),
+    requiresExemption: requiresExemption(vatCode),
+    quantity,
+    unitGross,
+    unitNet,
+    netTotal,
+    vatAmount,
+    grossTotal,
+  };
+}
+
+function updateTotals() {
+  let totalNet = 0;
+  let totalVat = 0;
+  let totalGross = 0;
+  const summary = new Map();
+  let exemptionNeeded = false;
+
+  const rows = Array.from(itemsBody.querySelectorAll("tr"));
+  rows.forEach((row) => {
+    const totals = calculateRowTotals(row);
+    if (totals.requiresExemption) {
+      exemptionNeeded = true;
+    }
+    const totalCell = row.querySelector(".item-total");
+    totalCell.textContent = formatCurrency(totals.grossTotal);
+
+    if (!totals.valid) {
+      return;
+    }
+
+    totalNet += totals.netTotal;
+    totalVat += totals.vatAmount;
+    totalGross += totals.grossTotal;
+
+    const existing = summary.get(totals.vatLabel) || { net: 0, vat: 0, gross: 0 };
+    existing.net += totals.netTotal;
+    existing.vat += totals.vatAmount;
+    existing.gross += totals.grossTotal;
+    summary.set(totals.vatLabel, existing);
+  });
+
+  totalNetLabel.textContent = `Suma netto: ${totalNet.toFixed(2)} PLN`;
+  totalVatLabel.textContent = `Kwota VAT: ${totalVat.toFixed(2)} PLN`;
+  totalGrossLabel.textContent = `Suma brutto: ${totalGross.toFixed(2)} PLN`;
+  renderRateSummary(summary);
+
+  if (exemptionNeeded) {
+    exemptionNoteWrapper.classList.remove("hidden");
+  } else {
+    exemptionNoteWrapper.classList.add("hidden");
+    exemptionNoteInput.value = "";
+  }
+}
+
+function renderRateSummary(summary) {
+  if (!summary || summary.size === 0) {
+    rateSummaryContainer.innerHTML = "";
+    return;
+  }
+
+  const entries = Array.from(summary.entries()).sort(([a], [b]) => a.localeCompare(b));
+  const markup = entries
+    .map(
+      ([label, totals]) =>
+        `<div class="rate-summary-item">
+          <span>${label}</span>
+          <span>Netto: ${totals.net.toFixed(2)} PLN</span>
+          <span>VAT: ${totals.vat.toFixed(2)} PLN</span>
+          <span>Brutto: ${totals.gross.toFixed(2)} PLN</span>
+        </div>`
+    )
+    .join("");
+  rateSummaryContainer.innerHTML = `<h4>Podsumowanie stawek</h4>${markup}`;
+}
+
+function collectInvoicePayload() {
+  const items = [];
+  const rows = Array.from(itemsBody.querySelectorAll("tr"));
+
+  rows.forEach((row) => {
+    const name = row.querySelector(".item-name")?.value.trim() ?? "";
+    const quantity = parseNumber(row.querySelector(".item-quantity")?.value);
+    const unitGross = parseNumber(row.querySelector(".item-gross")?.value);
+    const vatCode = row.querySelector(".item-vat")?.value ?? "23";
+
+    const hasValues = name || quantity > 0 || unitGross > 0;
+    if (!hasValues) {
+      return;
+    }
+
+    if (!name) {
+      throw new Error("Kazda pozycja musi miec nazwe.");
+    }
+    if (quantity <= 0) {
+      throw new Error("Ilosc musi byc wieksza od zera.");
+    }
+    if (unitGross <= 0) {
+      throw new Error("Cena brutto musi byc wieksza od zera.");
+    }
+
+    items.push({
+      name,
+      quantity: quantity.toFixed(2),
+      unit_price_gross: unitGross.toFixed(2),
+      vat_code: vatCode,
+    });
+  });
+
+  if (items.length === 0) {
+    throw new Error("Dodaj przynajmniej jedna pozycje.");
+  }
+
+  const saleDate = invoiceForm.elements.saleDate.value || null;
+  const exemptionNote = exemptionNoteInput.value.trim();
+  const requiresExemptionNote = items.some((item) => item.vat_code === "ZW" || item.vat_code === "0");
+  if (requiresExemptionNote && !exemptionNote) {
+    throw new Error("Podaj podstawe prawna zwolnienia dla pozycji rozliczanych jako ZW.");
+  }
+
+  const client = {
+    name: (invoiceForm.elements.clientName.value || "").trim(),
+    tax_id: (invoiceForm.elements.clientTaxId.value || "").trim(),
+    address_line: (invoiceForm.elements.clientAddress.value || "").trim(),
+    postal_code: (invoiceForm.elements.clientPostalCode.value || "").trim(),
+    city: (invoiceForm.elements.clientCity.value || "").trim(),
+  };
+
+  return {
+    sale_date: saleDate,
+    client,
+    items,
+    exemption_note: exemptionNote,
+  };
+}
+
+function renderInvoicePreview(invoice) {
+  if (!invoice || !currentBusiness) {
+    invoiceOutput.innerHTML = "<p>Brak danych faktury.</p>";
+    return;
+  }
+
+  const client = invoice.client || {};
+  const hasClientData = client.name || client.address_line || client.postal_code || client.city || client.tax_id;
+
+  const itemsRows = invoice.items
+    .map(
+      (item) => `
+        <tr>
+          <td>${item.name}</td>
+          <td>${parseNumber(item.quantity).toFixed(2)}</td>
+          <td>${formatCurrency(item.unit_price_net)}</td>
+          <td>${formatCurrency(item.net_total)}</td>
+          <td>${item.vat_label}</td>
+          <td>${formatCurrency(item.vat_amount)}</td>
+          <td>${formatCurrency(item.gross_total)}</td>
+        </tr>`
+    )
+    .join("");
+
+  const summaryRows = (invoice.summary || [])
+    .map(
+      (entry) =>
+        `<div class="rate-summary-item">
+          <span>${entry.vat_label}</span>
+          <span>Netto: ${formatCurrency(entry.net_total)}</span>
+          <span>VAT: ${formatCurrency(entry.vat_total)}</span>
+          <span>Brutto: ${formatCurrency(entry.gross_total)}</span>
+        </div>`
+    )
+    .join("");
+
+  invoiceOutput.innerHTML = `
+    <div class="invoice-preview-meta">
+      <span><strong>Numer:</strong> ${invoice.invoice_id}</span>
+      <span><strong>Data wystawienia:</strong> ${invoice.issued_at}</span>
+      <span><strong>Data sprzedazy:</strong> ${invoice.sale_date}</span>
+    </div>
+    <div class="invoice-preview-header">
+      <div class="invoice-preview-card">
+        <h4>Nabywca</h4>
+        ${
+          hasClientData
+            ? `
+              <p>${client.name || "---"}</p>
+              <p>${client.address_line || "---"}</p>
+              <p>${client.postal_code || ""} ${client.city || ""}</p>
+              <p>${client.tax_id ? `NIP: ${client.tax_id}` : ""}</p>
+            `
+            : "<p>Brak danych nabywcy.</p>"
+        }
+      </div>
+      <div class="invoice-preview-card">
+        <h4>Sprzedawca</h4>
+        <p>${currentBusiness.company_name}</p>
+        <p>${currentBusiness.owner_name}</p>
+        <p>${currentBusiness.address_line}</p>
+        <p>${currentBusiness.postal_code} ${currentBusiness.city}</p>
+        <p>NIP: ${currentBusiness.tax_id}</p>
+        <p>Konto: ${currentBusiness.bank_account}</p>
+      </div>
+    </div>
+    <table>
+      <thead>
+        <tr>
+          <th>Nazwa</th>
+          <th>Ilość</th>
+          <th>Cena jedn. netto</th>
+          <th>Wartość netto (pozycja)</th>
+          <th>Stawka VAT</th>
+          <th>Kwota VAT (pozycja)</th>
+          <th>Wartość brutto</th>
+        </tr>
+      </thead>
+      <tbody>${itemsRows}</tbody>
+    </table>
+    <div class="rate-summary">
+      <h4>Podsumowanie stawek</h4>
+      ${summaryRows}
+    </div>
+    <div class="invoice-preview-summary">
+      <span>Netto: ${formatCurrency(invoice.totals.net)}</span>
+      <span>VAT: ${formatCurrency(invoice.totals.vat)}</span>
+      <span>Brutto: ${formatCurrency(invoice.totals.gross)}</span>
+    </div>
+    ${
+      invoice.exemption_note
+        ? `<div class="invoice-preview-note"><strong>Podstawa prawna zwolnienia:</strong> ${invoice.exemption_note}</div>`
+        : ""
+    }
+  `;
+}
+
+function drawPartyBox(doc, title, lines, x, y, width) {
+  const lineHeight = 5;
+  const wrappedLines = lines.flatMap((line) => doc.splitTextToSize(line, width));
+  const boxHeight = wrappedLines.length * lineHeight + 14;
+
+  doc.roundedRect(x - 4, y - 8, width + 8, boxHeight, 2, 2);
+  doc.setFontSize(11);
+  doc.text(title, x, y);
+  doc.setFontSize(10);
+
+  let cursor = y + 5;
+  wrappedLines.forEach((line) => {
+    doc.text(line, x, cursor);
+    cursor += lineHeight;
+  });
+
+  return y - 8 + boxHeight;
+}
+
+function arrayBufferToBase64(buffer) {
+  const bytes = new Uint8Array(buffer);
+  const chunkSize = 0x8000;
+  let binary = "";
+  for (let offset = 0; offset < bytes.length; offset += chunkSize) {
+    const chunk = bytes.subarray(offset, Math.min(offset + chunkSize, bytes.length));
+    binary += String.fromCharCode.apply(null, chunk);
+  }
+  return btoa(binary);
+}
+
+const PDF_FONT_FILE = "Roboto-VariableFont_wdth,wght.ttf";
+const PDF_FONT_NAME = "RobotoPolish";
+
+async function ensurePdfFont() {
+  if (pdfFontPromise) {
+    return pdfFontPromise;
+  }
+
+  if (!window.jspdf || !window.jspdf.jsPDF) {
+    throw new Error("Biblioteka jsPDF nie zostala zaladowana.");
+  }
+
+  const { jsPDF } = window.jspdf;
+  const loadBase64 = async () => {
+    if (typeof window !== "undefined" && window.PDF_FONT_BASE64) {
+      return window.PDF_FONT_BASE64;
+    }
+    const response = await fetch(`/${encodeURIComponent(PDF_FONT_FILE)}`);
+    if (!response.ok) {
+      throw new Error(`Nie udalo sie pobrac czcionki Roboto (status ${response.status}).`);
+    }
+    const buffer = await response.arrayBuffer();
+    return arrayBufferToBase64(buffer);
+  };
+
+  pdfFontPromise = loadBase64().then((data) => {
+    pdfFontBase64 = data;
+    return data;
+  });
+
+  return pdfFontPromise;
+}
+
+async function generatePdf(business, invoice) {
+  if (!window.jspdf || !window.jspdf.jsPDF) {
+    alert("Biblioteka jsPDF nie zostala zaladowana. Sprawdz polaczenie z internetem.");
+    return;
+  }
+
+  let fontBase64;
+  try {
+    fontBase64 = await ensurePdfFont();
+  } catch (error) {
+    alert(error.message || "Nie udalo sie przygotowac czcionki do PDF.");
+    return;
+  }
+
+  const { jsPDF } = window.jspdf;
+  const doc = new jsPDF({ orientation: "portrait", unit: "mm", format: "a4" });
+  const marginX = 18;
+  let cursorY = 20;
+
+  if (!doc.getFontList()[PDF_FONT_NAME]) {
+    const embeddedFont = pdfFontBase64 || fontBase64;
+    doc.addFileToVFS(PDF_FONT_FILE, embeddedFont);
+    doc.addFont(PDF_FONT_FILE, PDF_FONT_NAME, "normal");
+  }
+
+  doc.setFont(PDF_FONT_NAME, "normal");
+  doc.setFontSize(16);
+  doc.text(`Faktura ${invoice.invoice_id}`, marginX, cursorY);
+  doc.setFontSize(10);
+  doc.text(`Data wystawienia: ${invoice.issued_at}`, marginX, cursorY + 6);
+  doc.text(`Data sprzedaży: ${invoice.sale_date}`, marginX, cursorY + 12);
+
+  cursorY += 22;
+  const columnWidth = 85;
+  const sellerX = marginX + columnWidth + 12;
+
+  const clientLines = invoice.client && (invoice.client.name || invoice.client.address_line || invoice.client.city || invoice.client.tax_id)
+    ? [
+        invoice.client.name || "---",
+        invoice.client.address_line || "",
+        `${(invoice.client.postal_code || "").trim()} ${(invoice.client.city || "").trim()}`.trim(),
+        invoice.client.tax_id ? `NIP: ${invoice.client.tax_id}` : "",
+      ].filter((line) => line && line.trim())
+    : ["Brak danych nabywcy"];
+
+  const sellerLines = [
+    business.company_name,
+    business.owner_name,
+    business.address_line,
+    `${business.postal_code} ${business.city}`.trim(),
+    `NIP: ${business.tax_id}`,
+    `Konto: ${business.bank_account}`,
+  ];
+
+  const buyerBottom = drawPartyBox(doc, "NABYWCA", clientLines, marginX, cursorY, columnWidth);
+  const sellerBottom = drawPartyBox(doc, "SPRZEDAWCA", sellerLines, sellerX, cursorY, columnWidth);
+  cursorY = Math.max(buyerBottom, sellerBottom) + 12;
+
+  const tableColumns = [
+    { key: "name", label: "Nazwa", width: 52 },
+    { key: "quantity", label: "Ilość", width: 16 },
+    { key: "unitNet", label: "Cena jedn. netto", width: 24 },
+    { key: "netTotal", label: "Wartość netto", width: 24 },
+    { key: "vatLabel", label: "Stawka VAT", width: 15 },
+    { key: "vatAmount", label: "Kwota VAT", width: 22 },
+    { key: "grossTotal", label: "Wartość brutto", width: 21 },
+  ];
+  const tableWidth = tableColumns.reduce((sum, col) => sum + col.width, 0);
+  const lineHeight = 5;
+  const headerLineHeight = 4.2;
+  tableColumns.forEach((column) => {
+    column.headerLines = doc.splitTextToSize(column.label, column.width - 4);
+  });
+  const headerHeight = Math.max(...tableColumns.map((column) => column.headerLines.length * headerLineHeight + 3));
+
+  doc.setFillColor(241, 243, 247);
+  doc.rect(marginX, cursorY, tableWidth, headerHeight, "F");
+  doc.rect(marginX, cursorY, tableWidth, headerHeight);
+  let offsetX = marginX;
+  doc.setFontSize(10);
+  tableColumns.forEach((column) => {
+    doc.rect(offsetX, cursorY, column.width, headerHeight);
+    column.headerLines.forEach((line, index) => {
+      const textY = cursorY + 4 + index * headerLineHeight;
+      doc.text((line || "").trim(), offsetX + 2, textY);
+    });
+    offsetX += column.width;
+  });
+  cursorY += headerHeight;
+
+  invoice.items.forEach((item) => {
+    const quantity = parseNumber(item.quantity).toFixed(2);
+    const unitNet = formatCurrency(item.unit_price_net);
+    const netTotal = formatCurrency(item.net_total);
+    const vatAmount = formatCurrency(item.vat_amount);
+    const grossTotal = formatCurrency(item.gross_total);
+
+    const wrapText = (text, width) =>
+      doc
+        .splitTextToSize(text ?? "", width)
+        .map((line) => line.trim());
+
+    const columnData = tableColumns.map((column) => {
+      switch (column.key) {
+        case "name":
+          return wrapText(item.name, column.width - 4);
+        case "quantity":
+          return [quantity];
+        case "unitNet":
+          return [unitNet];
+        case "netTotal":
+          return [netTotal];
+        case "vatLabel":
+          return [item.vat_label];
+        case "vatAmount":
+          return [vatAmount];
+        case "grossTotal":
+          return [grossTotal];
+        default:
+          return [""];
+      }
+    });
+
+    const rowHeight = Math.max(...columnData.map((data) => data.length)) * lineHeight + 2;
+    offsetX = marginX;
+    tableColumns.forEach((column, index) => {
+      doc.rect(offsetX, cursorY, column.width, rowHeight);
+      const lines = columnData[index];
+      lines.forEach((line, lineIndex) => {
+        const textY = cursorY + (lineIndex + 1) * lineHeight;
+        const content = (line || "").trim();
+        doc.text(content, offsetX + 2, textY);
+      });
+      offsetX += column.width;
+    });
+
+    cursorY += rowHeight;
+  });
+
+  cursorY += 10;
+  doc.setFontSize(11);
+  doc.text("Podsumowanie stawek:", marginX, cursorY);
+  cursorY += 6;
+
+  const summaryEntries = Array.isArray(invoice.summary) ? invoice.summary : [];
+  summaryEntries.forEach((entry) => {
+    const summaryLine = `${entry.vat_label} – Netto: ${formatCurrency(entry.net_total)} / VAT: ${formatCurrency(entry.vat_total)} / Brutto: ${formatCurrency(entry.gross_total)}`;
+    const wrapped = doc.splitTextToSize(summaryLine, 170);
+    wrapped.forEach((line) => {
+      doc.text((line || "").trim(), marginX, cursorY);
+      cursorY += lineHeight;
+    });
+  });
+
+  cursorY += 6;
+  doc.setFontSize(12);
+  doc.text(`Suma netto: ${formatCurrency(invoice.totals.net)}`, marginX, cursorY);
+  doc.text(`Suma VAT: ${formatCurrency(invoice.totals.vat)}`, marginX, cursorY + 6);
+  doc.text(`Suma brutto: ${formatCurrency(invoice.totals.gross)}`, marginX, cursorY + 12);
+  cursorY += 20;
+
+  if (invoice.exemption_note) {
+    doc.setFontSize(10);
+    const noteLines = doc.splitTextToSize(`Podstawa prawna zwolnienia: ${invoice.exemption_note}`, 170);
+    doc.text(noteLines, marginX, cursorY);
+  }
+
+  doc.save(`${invoice.invoice_id}.pdf`);
+}
+
+async function loadBusinessData() {
+  const data = await apiRequest("/api/business", {}, true);
+  currentBusiness = data.business;
+  renderBusinessDisplay(currentBusiness);
+  fillBusinessForm(currentBusiness);
+}
+
+function resetInvoiceForm() {
+  invoiceForm.reset();
+  exemptionNoteInput.value = "";
+  exemptionNoteWrapper.classList.add("hidden");
+  itemsBody.innerHTML = "";
+  createItemRow();
+  const today = new Date().toISOString().slice(0, 10);
+  invoiceForm.elements.saleDate.value = today;
+}
+
+async function bootstrapApp() {
+  try {
+    await loadBusinessData();
+    setState("app");
+  } catch (error) {
+    console.error(error);
+    authToken = null;
+    sessionStorage.removeItem("invoiceAuthToken");
+    showFeedback(loginFeedback, error.message || "Nie udalo sie pobrac danych firmy.");
+    setState("login");
+  }
+}
+
+async function initialize() {
+  resetInvoiceForm();
+  try {
+    const status = await apiRequest("/api/status");
+    if (!status.configured) {
+      setState("setup");
+      return;
+    }
+
+    if (authToken) {
+      await bootstrapApp();
+    } else {
+      setState("login");
+    }
+  } catch (error) {
+    console.error(error);
+    setState("setup");
+    showFeedback(setupFeedback, "Nie udalo sie nawiazac polaczenia z serwerem.");
+  }
+}
+
+setupForm.addEventListener("submit", async (event) => {
+  event.preventDefault();
+  clearFeedback(setupFeedback);
+
+  const formData = new FormData(setupForm);
+  const password = formData.get("password")?.toString() ?? "";
+  const confirmPassword = formData.get("confirm_password")?.toString() ?? "";
+
+  if (password !== confirmPassword) {
+    showFeedback(setupFeedback, "Hasla musza byc identyczne.");
+    return;
+  }
+
+  if (password.trim().length < 4) {
+    showFeedback(setupFeedback, "Haslo musi miec co najmniej 4 znaki.");
+    return;
+  }
+
+  const payload = {
+    company_name: formData.get("company_name")?.toString().trim(),
+    owner_name: formData.get("owner_name")?.toString().trim(),
+    address_line: formData.get("address_line")?.toString().trim(),
+    postal_code: formData.get("postal_code")?.toString().trim(),
+    city: formData.get("city")?.toString().trim(),
+    tax_id: formData.get("tax_id")?.toString().trim(),
+    bank_account: formData.get("bank_account")?.toString().trim(),
+    password,
+  };
+
+  try {
+    await apiRequest("/api/setup", { method: "POST", body: payload });
+    showFeedback(setupFeedback, "Dane zapisane. Mozesz sie zalogowac.", "success");
+    setTimeout(() => {
+      setState("login");
+      clearFeedback(setupFeedback);
+      setupForm.reset();
+    }, 1500);
+  } catch (error) {
+    showFeedback(setupFeedback, error.message || "Nie udalo sie zapisac danych.");
+  }
+});
+
+loginForm.addEventListener("submit", async (event) => {
+  event.preventDefault();
+  clearFeedback(loginFeedback);
+
+  const password = loginForm.elements.password.value;
+  if (!password) {
+    showFeedback(loginFeedback, "Podaj haslo.");
+    return;
+  }
+
+  try {
+    const response = await apiRequest("/api/login", { method: "POST", body: { password } });
+    authToken = response.token;
+    sessionStorage.setItem("invoiceAuthToken", authToken);
+    loginForm.reset();
+    await bootstrapApp();
+  } catch (error) {
+    showFeedback(loginFeedback, error.message || "Logowanie nie powiodlo sie.");
+  }
+});
+
+toggleBusinessFormButton.addEventListener("click", () => {
+  const isHidden = businessForm.classList.contains("hidden");
+  if (isHidden) {
+    fillBusinessForm(currentBusiness);
+    businessForm.classList.remove("hidden");
+    toggleBusinessFormButton.textContent = "Ukryj formularz";
+  } else {
+    businessForm.classList.add("hidden");
+    toggleBusinessFormButton.textContent = "Edytuj dane";
+    clearFeedback(businessFeedback);
+  }
+});
+
+cancelBusinessUpdateButton.addEventListener("click", () => {
+  businessForm.classList.add("hidden");
+  toggleBusinessFormButton.textContent = "Edytuj dane";
+  clearFeedback(businessFeedback);
+});
+
+businessForm.addEventListener("submit", async (event) => {
+  event.preventDefault();
+  clearFeedback(businessFeedback);
+
+  const formData = new FormData(businessForm);
+  const payload = {
+    company_name: formData.get("company_name")?.toString().trim(),
+    owner_name: formData.get("owner_name")?.toString().trim(),
+    address_line: formData.get("address_line")?.toString().trim(),
+    postal_code: formData.get("postal_code")?.toString().trim(),
+    city: formData.get("city")?.toString().trim(),
+    tax_id: formData.get("tax_id")?.toString().trim(),
+    bank_account: formData.get("bank_account")?.toString().trim(),
+  };
+
+  try {
+    const data = await apiRequest("/api/business", { method: "PUT", body: payload }, true);
+    currentBusiness = data.business;
+    renderBusinessDisplay(currentBusiness);
+    showFeedback(businessFeedback, "Dane sprzedawcy zaktualizowane.", "success");
+    setTimeout(() => clearFeedback(businessFeedback), 2000);
+  } catch (error) {
+    showFeedback(businessFeedback, error.message || "Nie udalo sie zaktualizowac danych.");
+  }
+});
+
+invoiceForm.addEventListener("submit", async (event) => {
+  event.preventDefault();
+  try {
+    const payload = collectInvoicePayload();
+    const response = await apiRequest("/api/invoices", { method: "POST", body: payload }, true);
+    lastInvoice = response.invoice;
+    renderInvoicePreview(lastInvoice);
+    invoiceResult.classList.remove("hidden");
+    resetInvoiceForm();
+  } catch (error) {
+    alert(error.message || "Nie udalo sie wygenerowac faktury.");
+  }
+});
+
+addItemButton.addEventListener("click", () => {
+  createItemRow();
+});
+
+downloadButton.addEventListener("click", async () => {
+  if (!lastInvoice || !currentBusiness) {
+    alert("Brak faktury do pobrania. Wygeneruj ja najpierw.");
+    return;
+  }
+  await generatePdf(currentBusiness, lastInvoice);
+});
+
+logoutButton.addEventListener("click", () => {
+  authToken = null;
+  sessionStorage.removeItem("invoiceAuthToken");
+  lastInvoice = null;
+  currentBusiness = null;
+  invoiceResult.classList.add("hidden");
+  setState("login");
+});
+
+initialize().catch((error) => {
+  console.error(error);
+  showFeedback(setupFeedback, "Nie udalo sie uruchomic aplikacji.");
+});

styles.css

@@ -1,1041 +0,0 @@
-:root {
-  --bg: #e9eef5;
-  --panel-bg: #ffffff;
-  --surface: #f7f9ff;
-  --surface-alt: #eef3ff;
-  --text: #101828;
-  --muted: #667085;
-  --accent: #2563eb;
-  --accent-dark: #1d4ed8;
-  --accent-soft: rgba(37, 99, 235, 0.1);
-  --danger: #dc2626;
-  --border: #dfe4ee;
-  --radius: 16px;
-  --radius-sm: 10px;
-  --shadow: 0 25px 60px rgba(15, 23, 42, 0.08);
-  font-family: "Roboto", "Segoe UI", Tahoma, sans-serif;
-}
-
-*,
-*::before,
-*::after {
-  box-sizing: border-box;
-}
-
-body {
-  margin: 0;
-  font-family: "Roboto", "Segoe UI", Tahoma, sans-serif;
-  color: var(--text);
-  line-height: 1.6;
-  background: radial-gradient(circle at top, #f5f7ff 0%, #e7edf8 60%, #dee5f1 100%);
-  min-height: 100vh;
-  -webkit-font-smoothing: antialiased;
-}
-
-.container {
-  max-width: 1200px;
-  margin: 0 auto;
-  padding: 48px 32px 80px;
-  display: grid;
-  gap: 32px;
-}
-
-.brand-banner {
-  display: flex;
-  justify-content: center;
-  align-items: center;
-  padding: 8px 0 16px;
-}
-
-.brand-logo {
-  max-width: 220px;
-  width: 100%;
-  height: auto;
-  border-radius: 16px;
-  box-shadow: 0 12px 35px rgba(15, 23, 42, 0.18);
-}
-
-.hero-panel {
-  background: linear-gradient(135deg, #fdfbff 0%, #f5f7ff 50%, #eef3ff 100%);
-}
-
-.hero-columns {
-  display: grid;
-  grid-template-columns: minmax(0, 1.2fr) minmax(300px, 0.8fr);
-  gap: 40px;
-  align-items: stretch;
-}
-
-.hero-content {
-  display: grid;
-  gap: 8px;
-}
-
-.hero-lead {
-  margin: 0;
-  color: var(--text);
-  font-size: 16px;
-}
-
-.eyebrow {
-  font-size: 13px;
-  text-transform: uppercase;
-  letter-spacing: 0.12em;
-  color: var(--accent);
-  margin: 0;
-}
-
-.app-title {
-  font-size: 24px;
-  margin: 0;
-  font-weight: 700;
-  line-height: 1.15;
-  display: inline-block;
-  width: fit-content;
-}
-
-.app-title::after {
-  content: "";
-  display: block;
-  width: 100%;
-  height: 3px;
-  background: var(--accent);
-  margin-top: 8px;
-  border-radius: 999px;
-}
-
-.app-description {
-  font-size: 16px;
-  color: var(--muted);
-  margin: 0;
-  max-width: 520px;
-}
-
-.header-highlights {
-  list-style: none;
-  padding: 0;
-  margin: 12px 0 0;
-  display: grid;
-  gap: 16px;
-  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
-}
-
-.header-highlights li {
-  padding: 18px;
-  border-radius: var(--radius-sm);
-  border: 1px solid rgba(16, 24, 40, 0.08);
-  background: #ffffff;
-  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.6);
-  display: grid;
-  gap: 6px;
-}
-
-.header-highlights strong {
-  font-size: 15px;
-  color: var(--accent);
-}
-
-.header-highlights span {
-  font-size: 14px;
-  color: var(--muted);
-}
-
-.panel {
-  background: var(--panel-bg);
-  border-radius: var(--radius);
-  box-shadow: var(--shadow);
-  padding: 36px;
-  border: 1px solid rgba(15, 23, 42, 0.08);
-}
-
-.auth-card {
-  border: 1px solid rgba(16, 24, 40, 0.08);
-  border-radius: var(--radius);
-  padding: 28px 32px;
-  background: #ffffff;
-  display: grid;
-  gap: 20px;
-  max-width: 520px;
-  margin: 0 auto;
-  width: 100%;
-  box-shadow: 0 20px 35px rgba(15, 23, 42, 0.08);
-}
-
-.auth-panel {
-  display: grid;
-  gap: 24px;
-  height: 100%;
-  background: rgba(255, 255, 255, 0.8);
-  border-radius: var(--radius);
-  padding: 24px 28px;
-  border: 2px solid rgba(37, 99, 235, 0.4);
-  box-shadow: 0 20px 35px rgba(15, 23, 42, 0.1);
-}
-
-.auth-panel-header {
-  display: grid;
-  gap: 8px;
-}
-
-.auth-headline {
-  margin: 0;
-  font-size: 22px;
-}
-
-.auth-copy {
-  margin: 0;
-  color: var(--muted);
-  font-size: 15px;
-}
-
-.auth-login {
-  display: flex;
-  justify-content: center;
-}
-
-.login-card {
-  width: 100%;
-}
-
-#register-section {
-  display: flex;
-  justify-content: center;
-}
-
-#register-section .register-card {
-  max-width: 640px;
-  width: 100%;
-}
-
-.register-header {
-  display: flex;
-  justify-content: space-between;
-  align-items: center;
-  gap: 16px;
-}
-
-.auth-card h3 {
-  margin: 0;
-}
-
-.auth-card .form {
-  gap: 18px;
-  width: 100%;
-}
-
-
-.auth-actions {
-  margin-top: 4px;
-  display: flex;
-  flex-wrap: wrap;
-  align-items: center;
-  justify-content: space-between;
-  gap: 12px;
-  font-size: 14px;
-  color: var(--muted);
-}
-
-.ghost-button {
-  padding: 12px 20px;
-  border: 1px solid rgba(37, 99, 235, 0.35);
-  border-radius: var(--radius-sm);
-  background: transparent;
-  color: var(--accent);
-  font-weight: 600;
-  cursor: pointer;
-  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
-}
-
-.ghost-button:hover {
-  background: rgba(37, 99, 235, 0.08);
-}
-
-.form-divider {
-  border: none;
-  border-top: 1px solid var(--border);
-  margin: 16px 0 0;
-}
-
-.register-fields {
-  display: grid;
-  gap: 28px;
-}
-
-.register-credentials {
-  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
-}
-
-.register-company {
-  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
-}
-
-.hidden {
-  display: none;
-}
-
-.form {
-  display: grid;
-  gap: 24px;
-  width: 100%;
-}
-
-.client-lookup {
-  position: relative;
-  display: grid;
-  gap: 8px;
-}
-
-.client-lookup label {
-  font-size: 13px;
-  font-weight: 600;
-  color: var(--muted);
-}
-
-.client-lookup input {
-  width: 100%;
-}
-
-.client-suggestions {
-  position: absolute;
-  top: 100%;
-  left: 0;
-  right: 0;
-  margin-top: 6px;
-  background: #ffffff;
-  border-radius: var(--radius-sm);
-  border: 1px solid var(--border);
-  box-shadow: 0 15px 35px rgba(15, 23, 42, 0.15);
-  z-index: 5;
-  max-height: 320px;
-  overflow-y: auto;
-  display: grid;
-}
-
-.client-suggestion {
-  display: flex;
-  flex-direction: column;
-  align-items: flex-start;
-  gap: 2px;
-  padding: 10px 14px;
-  border: none;
-  border-bottom: 1px solid rgba(15, 23, 42, 0.08);
-  background: none;
-  cursor: pointer;
-  text-align: left;
-  font-size: 14px;
-}
-
-.client-suggestion:last-child {
-  border-bottom: none;
-}
-
-.client-suggestion strong {
-  font-size: 14px;
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-.logo-preview {
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-.logo-preview-label {
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-
-.logo-preview img {
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-.items-section {
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-.items-header {
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-.items-table-wrapper {
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-
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-
-.items-table th,
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-
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-.totals {
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-.rate-summary {
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-}
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-}
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-}
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-  flex-wrap: wrap;
-  gap: 8px;
-}
-
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-  margin-top: 12px;
-  text-align: center;
-  padding: 12px 0;
-}
-
-@media (max-width: 1024px) {
-  .container {
-    padding: 40px 24px 64px;
-  }
-  .hero-columns {
-    grid-template-columns: 1fr;
-  }
-}
-
-@media (max-width: 900px) {
-  .hero-columns {
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-  }
-}
-
-@media (max-width: 640px) {
-  .container {
-    padding: 32px 16px 56px;
-  }
-
-  .panel {
-    padding: 24px;
-  }
-
-  .brand-logo {
-    max-width: 160px;
-  }
-
-  .app-title {
-    font-size: 24px;
-  }
-
-  .auth-panel {
-    grid-template-columns: 1fr;
-  }
-
-  .app-header {
-    flex-direction: column;
-    gap: 12px;
-    align-items: flex-start;
-  }
-
-  .business-section,
-  .items-section {
-    padding: 20px;
-  }
-}

templates/index.html

@@ -0,0 +1,209 @@
+<!DOCTYPE html>
+<html lang="pl">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Generator faktur</title>
+  <link rel="stylesheet" href="{{ url_for('static', filename='css/styles.css') }}">
+</head>
+<body>
+  <main class="container">
+    <h1>Generator faktur</h1>
+
+    <section id="setup-section" class="panel hidden">
+      <h2>Konfiguracja danych firmy</h2>
+      <form id="setup-form" class="form">
+        <div class="field-grid">
+          <label>
+            Nazwa firmy
+            <input type="text" name="company_name" required>
+          </label>
+          <label>
+            Imie i nazwisko wlasciciela
+            <input type="text" name="owner_name" required>
+          </label>
+          <label>
+            Ulica i numer
+            <input type="text" name="address_line" required>
+          </label>
+          <label>
+            Kod pocztowy
+            <input type="text" name="postal_code" required>
+          </label>
+          <label>
+            Miejscowosc
+            <input type="text" name="city" required>
+          </label>
+          <label>
+            NIP
+            <input type="text" name="tax_id" required>
+          </label>
+          <label>
+            Numer konta bankowego
+            <input type="text" name="bank_account" required>
+          </label>
+          <label>
+            Haslo
+            <input type="password" name="password" required>
+          </label>
+          <label>
+            Powtorz haslo
+            <input type="password" name="confirm_password" required>
+          </label>
+        </div>
+        <button type="submit">Zapisz dane</button>
+        <p class="hint">Dane przechowywane sa na serwerze lokalnym.</p>
+      </form>
+      <p id="setup-feedback" class="feedback"></p>
+    </section>
+
+    <section id="login-section" class="panel hidden">
+      <h2>Logowanie</h2>
+      <form id="login-form" class="form">
+        <label>
+          Haslo
+          <input type="password" name="password" required>
+        </label>
+        <button type="submit">Zaloguj</button>
+      </form>
+      <p id="login-feedback" class="feedback"></p>
+    </section>
+
+    <section id="app-section" class="panel hidden">
+      <header class="invoice-header">
+        <h2>Panel faktur</h2>
+        <button id="logout-button" type="button" class="link-button">Wyloguj</button>
+      </header>
+
+      <section class="business-section">
+        <div class="business-section-header">
+          <h3>Dane sprzedawcy</h3>
+          <button id="toggle-business-form" type="button" class="link-button">Edytuj dane</button>
+        </div>
+        <div id="business-display" class="business-display"></div>
+        <form id="business-form" class="form hidden">
+          <div class="field-grid">
+            <label>
+              Nazwa firmy
+              <input type="text" name="company_name" required>
+            </label>
+            <label>
+              Imie i nazwisko wlasciciela
+              <input type="text" name="owner_name" required>
+            </label>
+            <label>
+              Ulica i numer
+              <input type="text" name="address_line" required>
+            </label>
+            <label>
+              Kod pocztowy
+              <input type="text" name="postal_code" required>
+            </label>
+            <label>
+              Miejscowosc
+              <input type="text" name="city" required>
+            </label>
+            <label>
+              NIP
+              <input type="text" name="tax_id" required>
+            </label>
+            <label>
+              Numer konta bankowego
+              <input type="text" name="bank_account" required>
+            </label>
+          </div>
+          <div class="form-actions">
+            <button type="submit">Zapisz</button>
+            <button id="cancel-business-update" type="button" class="link-button">Anuluj</button>
+          </div>
+          <p id="business-feedback" class="feedback"></p>
+        </form>
+      </section>
+
+      <form id="invoice-form" class="form">
+        <fieldset>
+          <legend>Informacje o fakturze</legend>
+          <label>
+            Data sprzedazy / wykonania uslugi
+            <input type="date" name="saleDate">
+          </label>
+        </fieldset>
+
+        <fieldset>
+          <legend>Dane nabywcy</legend>
+          <div class="field-grid">
+            <label>
+              Nazwa / Imie i nazwisko
+              <input type="text" name="clientName">
+            </label>
+            <label>
+              NIP
+              <input type="text" name="clientTaxId">
+            </label>
+            <label>
+              Ulica i numer
+              <input type="text" name="clientAddress">
+            </label>
+            <label>
+              Kod pocztowy
+              <input type="text" name="clientPostalCode">
+            </label>
+            <label>
+              Miejscowosc
+              <input type="text" name="clientCity">
+            </label>
+          </div>
+        </fieldset>
+
+        <section class="items-section">
+          <header class="items-header">
+            <h3>Pozycje faktury</h3>
+            <button type="button" id="add-item-button">Dodaj pozycje</button>
+          </header>
+          <div class="items-table-wrapper">
+            <table class="items-table">
+              <thead>
+                <tr>
+                  <th>Nazwa towaru/uslugi</th>
+                  <th>Ilosc</th>
+                  <th>Cena jedn. brutto (PLN)</th>
+                  <th>Stawka VAT</th>
+                  <th>Wartosc brutto (PLN)</th>
+                  <th></th>
+                </tr>
+              </thead>
+              <tbody id="items-body"></tbody>
+            </table>
+          </div>
+        </section>
+
+        <div id="totals-container" class="totals">
+          <span id="total-net">Suma netto: 0.00 PLN</span>
+          <span id="total-vat">Kwota VAT: 0.00 PLN</span>
+          <span id="total-gross">Suma brutto: 0.00 PLN</span>
+        </div>
+
+        <section id="rate-summary" class="rate-summary"></section>
+
+        <div id="exemption-note-wrapper" class="hidden">
+          <label>
+            Podstawa prawna zwolnienia (stosowana dla pozycji ZW)
+            <textarea id="exemption-note" rows="3" placeholder="np. Art. 43 ust. 1 pkt 19 ustawy o VAT"></textarea>
+          </label>
+        </div>
+
+        <button type="submit">Generuj fakture</button>
+      </form>
+
+      <section id="invoice-result" class="panel hidden">
+        <h3>Podglad faktury</h3>
+        <div id="invoice-output" class="invoice-preview"></div>
+        <button id="download-button" type="button">Pobierz jako plik PDF</button>
+      </section>
+    </section>
+  </main>
+
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/2.5.1/jspdf.umd.min.js" defer></script>
+  <script src="{{ url_for('static', filename='js/main.js') }}" defer></script>
+</body>
+</html>