#!/usr/bin/env python3
"""
Step 2 — Conversione PDF → Markdown grezzo

Usa pymupdf4llm (PyMuPDF puro C, zero modelli ML, ~30-50 MB RAM)
per convertire ogni PDF in sources/ e organizza l'output in:
  step-2/<stem>/raw.md    — MD grezzo, non modificare mai
  step-2/<stem>/clean.md  — copia di lavoro per lo step 4

Uso:
    python step-2/convert_pdf.py                        # tutti i PDF in sources/
    python step-2/convert_pdf.py --pdf sources/doc.pdf  # un solo PDF
"""

import argparse
import shutil
import sys
from pathlib import Path

import pymupdf4llm


def convert_pdf(pdf_path: Path, project_root: Path) -> bool:
    stem = pdf_path.stem
    out_dir = project_root / "step-2" / stem
    raw_md = out_dir / "raw.md"
    clean_md = out_dir / "clean.md"

    print(f"\nConversione: {pdf_path.name}")
    print(f"  Output:    step-2/{stem}/")

    if raw_md.exists():
        print(f"  ⚠️  raw.md già presente — skip")
        print(f"       (elimina {raw_md} per riconvertire)")
        return True

    out_dir.mkdir(parents=True, exist_ok=True)

    print(f"  Conversione in corso...")
    md_text = pymupdf4llm.to_markdown(str(pdf_path))

    raw_md.write_text(md_text, encoding="utf-8")
    shutil.copy2(raw_md, clean_md)

    size_kb = raw_md.stat().st_size // 1024
    print(f"  ✅ raw.md salvato ({size_kb} KB)")
    print(f"  ✅ clean.md creato (copia di lavoro per step 4)")
    return True


if __name__ == "__main__":
    project_root = Path(__file__).parent.parent

    parser = argparse.ArgumentParser(description="Step 2 — Conversione PDF → Markdown")
    parser.add_argument("--pdf", help="Percorso di un singolo PDF da convertire")
    args = parser.parse_args()

    if args.pdf:
        pdf_path = Path(args.pdf)
        if not pdf_path.exists():
            print(f"Errore: file non trovato — {args.pdf}")
            sys.exit(1)
        pdfs = [pdf_path]
    else:
        sources_dir = project_root / "sources"
        if not sources_dir.exists():
            print(f"Errore: cartella sources/ non trovata in {project_root}")
            sys.exit(1)
        pdfs = sorted(sources_dir.glob("*.pdf"))
        if not pdfs:
            print(f"Errore: nessun PDF trovato in {sources_dir}")
            sys.exit(1)

    results = [convert_pdf(p, project_root) for p in pdfs]

    ok_count = sum(results)
    total = len(results)
    print(f"\n{'✅' if all(results) else '⚠️ '} {ok_count}/{total} PDF convertiti")

    sys.exit(0 if all(results) else 1)