import os
import re
from datetime import datetime
from typing import List

import streamlit as st
from pypdf import PdfReader

from reportlab.lib.pagesizes import A4
from reportlab.pdfgen import canvas
from reportlab.lib.units import mm


KEY_RE = re.compile(r"\b\d{44}\b")


def extract_keys_from_pdf(pdf_path: str) -> List[str]:
    reader = PdfReader(pdf_path)
    found: List[str] = []
    seen = set()

    for page in reader.pages:
        text = page.extract_text() or ""
        for k in KEY_RE.findall(text):
            if k not in seen:
                seen.add(k)
                found.append(k)

    return found


def safe_date_default() -> str:
    return datetime.now().strftime("%d/%m/%Y")


def normalize_hora(hora_input: str) -> str:
    if not hora_input:
        return "_____ : _____"
    s = hora_input.strip()
    if s in {"_____:_____", "_____ : _____", "____ : ____"}:
        return "_____ : _____"
    return s


def render_print_pdf(out_path: str, data_coleta: str, hora_coleta: str, keys: List[str]):
    c = canvas.Canvas(out_path, pagesize=A4)
    _, h = A4

    left = 20 * mm
    top = h - 20 * mm
    line_h = 6.2 * mm

    def draw(text: str, y: float, size=11, bold=False) -> float:
        c.setFont("Helvetica-Bold" if bold else "Helvetica", size)
        c.drawString(left, y, text)
        return y - line_h

    y = top

    # Cabeçalho (modelo)
    y = draw("CLIENTE:", y)
    y -= line_h * 1.3

    y = draw("DATA DA COLETA:", y)
    y = draw(data_coleta, y)
    y -= line_h * 0.6

    y = draw("HORA DA COLETA:", y)
    y = draw(hora_coleta, y)
    y -= line_h * 0.9

    # Título da lista
    y = draw("CHAVES DE ACESSO:", y)
    y -= line_h * 0.2

    c.setFont("Helvetica", 10.8)
    for k in keys:
        if y < 40 * mm:
            c.showPage()
            y = top
            c.setFont("Helvetica", 10.8)
        c.drawString(left, y, k)
        y -= line_h * 0.85

    y -= line_h * 0.8
    y = draw(f"TOTAL DA REMESSA:  {len(keys)} VOLUMES", y)

    # Assinaturas no rodapé
    if y < 55 * mm:
        c.showPage()

    y_sig = 25 * mm
    c.setFont("Helvetica", 9.5)
    c.drawString(left + 70 * mm, y_sig + 12, "ASSINATURA DO REPRESENTANTE")
    c.drawString(left + 140 * mm, y_sig + 12, "ASSINATURA DO MOTORISTA")
    c.line(left + 55 * mm, y_sig + 10, left + 118 * mm, y_sig + 10)
    c.line(left + 130 * mm, y_sig + 10, left + 193 * mm, y_sig + 10)

    c.save()


st.set_page_config(page_title="Extrator de Chaves NF-e", layout="centered")
st.title("Extrator de Chaves NF-e (PDF → PDF para imprimir)")

pdf = st.file_uploader("Envie o PDF", type=["pdf"])
data_coleta = st.text_input("Data da coleta", value=safe_date_default())
hora_coleta = st.text_input("Hora da coleta", value="_____ : _____")

if pdf is not None:
    st.caption(f"Arquivo: {pdf.name}")

if st.button("Gerar arquivos", disabled=(pdf is None)):
    tmp_in = os.path.join("/tmp", f"entrada_{datetime.now().strftime('%Y%m%d-%H%M%S')}.pdf")
    with open(tmp_in, "wb") as f:
        f.write(pdf.read())

    keys = extract_keys_from_pdf(tmp_in)
    if not keys:
        st.error("Não encontrei chaves de acesso (44 dígitos) no PDF.")
        st.stop()

    data_coleta = (data_coleta or safe_date_default()).strip()
    hora_coleta_norm = normalize_hora(hora_coleta)

    ts = datetime.now().strftime("%Y%m%d-%H%M%S")
    out_pdf = os.path.join("/tmp", f"chaves_prontas_{ts}.pdf")
    out_txt = os.path.join("/tmp", f"chaves_{ts}.txt")

    render_print_pdf(out_pdf, data_coleta, hora_coleta_norm, keys)

    with open(out_txt, "w", encoding="utf-8") as f:
        f.write("\n".join(keys) + "\n")

    st.success(f"{len(keys)} chaves encontradas.")

    with open(out_pdf, "rb") as f:
        st.download_button(
            "Baixar PDF pronto para imprimir",
            data=f,
            file_name=os.path.basename(out_pdf),
            mime="application/pdf",
        )

    with open(out_txt, "rb") as f:
        st.download_button(
            "Baixar TXT (opcional)",
            data=f,
            file_name=os.path.basename(out_txt),
            mime="text/plain",
        )

    st.text_area("Prévia (primeiras 10 chaves)", value="\n".join(keys[:10]), height=200)