"""Fetch document bodies from ``link`` and write PDFs (fallback: ``full_text``)."""

from __future__ import annotations

import io
import sys
import time
from pathlib import Path

import openpyxl
import requests
from bs4 import BeautifulSoup
from pypdf import PdfReader

from legex.pdf_export.core import safe_slug, write_one_pdf
from legex.pdf_export.font_keys import font_key_for_workbook
from legex.pdf_export.workbook import cell, discover_goldensets, header_map

UA = "Mozilla/5.0 (compatible; LegexPDFExport/1.0)"


def is_hf_dataset_stub_url(url: str) -> bool:
    u = url.lower()
    return "huggingface.co" in u and "/datasets/" in u


def effective_timeout(url: str, configured: float) -> float:
    u = url.lower()
    if "hcourt.gov.au" in u:
        return min(configured, 10.0)
    if "openlegaldata.io" in u:
        return min(configured, 12.0)
    return configured


def fetch_document_text(url: str, timeout: float = 28.0) -> str:
    url = (url or "").strip()
    if not url or not url.startswith("http"):
        return ""
    last_err: str | None = None
    for attempt in range(2):
        try:
            r = requests.get(
                url,
                timeout=timeout,
                headers={"User-Agent": UA, "Accept": "text/html,application/pdf;q=0.9,*/*;q=0.8"},
                allow_redirects=True,
            )
            r.raise_for_status()
            data = r.content
            if len(data) >= 4 and data[:4] == b"%PDF":
                reader = PdfReader(io.BytesIO(data))
                return "\n\n".join((p.extract_text() or "") for p in reader.pages)
            enc = r.encoding or "utf-8"
            try:
                html = data.decode(enc, errors="replace")
            except LookupError:
                html = data.decode("utf-8", errors="replace")
            soup = BeautifulSoup(html, "lxml")
            for tag in soup(["script", "style", "noscript"]):
                tag.decompose()
            text = soup.get_text("\n")
            lines = [ln.strip() for ln in text.splitlines()]
            return "\n".join(ln for ln in lines if ln)
        except Exception as e:
            last_err = str(e)
            if attempt < 1:
                time.sleep(1.2 * (attempt + 1))
    if last_err:
        return f"[Abruf fehlgeschlagen: {last_err}]\n"
    return ""


def pick_body(
    link_val: str,
    sheet_full: str | None,
    pause_s: float,
    req_timeout: float,
) -> tuple[str, str]:
    time.sleep(pause_s)
    link_val = (link_val or "").strip()
    sheet = (sheet_full or "").strip()

    if link_val and is_hf_dataset_stub_url(link_val):
        if sheet:
            return sheet, "full_text (HF-Dataset-Link)"
        return "(kein Volltext in der Zeile trotz HF-Link)", "leer"

    fetched = (
        fetch_document_text(link_val, timeout=effective_timeout(link_val, req_timeout))
        if link_val
        else ""
    )
    if fetched and not fetched.startswith("[Abruf fehlgeschlagen"):
        return fetched.strip(), "URL"
    if sheet:
        return sheet, "full_text (Fallback)"
    if fetched:
        return fetched.strip(), "URL (Fehlermeldung)"
    return "(kein Volltext — weder URL noch Tabellenfeld)", "leer"


def export_workbook(
    xlsx: Path,
    out_root: Path,
    *,
    pause_s: float,
    limit: int | None,
    req_timeout: float,
    resume: bool,
) -> int:
    label = xlsx.parent.name
    out_dir = out_root / label
    font_key = font_key_for_workbook(xlsx)

    wb = openpyxl.load_workbook(xlsx, read_only=True, data_only=True)
    if "GOLDENSET" not in wb.sheetnames:
        wb.close()
        print(f"  skip {xlsx.name}: kein Sheet GOLDENSET", flush=True)
        return 0
    ws = wb["GOLDENSET"]
    rows = ws.iter_rows(min_row=1, max_row=ws.max_row, values_only=True)
    header_row = next(rows, None)
    if not header_row:
        wb.close()
        return 0
    h = header_map(header_row)
    idx_case = h.get("case_id")
    idx_link = h.get("link")
    idx_text = h.get("full_text")
    if idx_link is None:
        wb.close()
        print(f"  skip {xlsx.name}: keine Spalte 'link'", flush=True)
        return 0

    used_names: dict[str, int] = {}
    count = 0
    row_idx = 1
    for row in rows:
        row_idx += 1
        if not row:
            continue
        link_val = cell(row, idx_link) or ""
        case_id = cell(row, idx_case)
        sheet_full = cell(row, idx_text) if idx_text is not None else None
        if (
            not str(case_id or "").strip()
            and not link_val.strip()
            and not (sheet_full or "").strip()
        ):
            continue
        base = safe_slug(case_id, link_val or None, row_idx)
        used_names[base] = used_names.get(base, 0) + 1
        fname = f"{base}_{used_names[base]}.pdf" if used_names[base] > 1 else f"{base}.pdf"
        out_path = out_dir / fname
        if resume and out_path.exists() and out_path.stat().st_size > 80:
            count += 1
            if count % 25 == 0:
                print(f"  {label}: {count} (Bestand übersprungen) …", flush=True)
            if limit is not None and count >= limit:
                break
            continue

        body, prov = pick_body(link_val, sheet_full, pause_s, req_timeout)
        write_one_pdf(out_path, str(case_id or ""), link_val, body, font_key, text_source=prov)
        count += 1
        if count % 10 == 0:
            print(f"  {label}: {count} …", flush=True)
        if limit is not None and count >= limit:
            break
    wb.close()
    print(f"  {label}: fertig, {count} PDFs", flush=True)
    return count


def collect_workbooks(data_dir: Path, input_dirs: list[Path] | None) -> list[Path]:
    if input_dirs:
        files: list[Path] = []
        for d in input_dirs:
            if not d.is_dir():
                print("Ordner fehlt:", d, file=sys.stderr)
                continue
            files.extend(sorted(d.glob("Goldenset_*.xlsx")))
        return sorted(files, key=lambda p: (p.stem.lower(), str(p)))
    return discover_goldensets(data_dir)