"""HWP(library) 백필 — 지정 PKM 폴더의 .hwp 를 content-hash dedup 후 일회성 ingest.

산업안전기사 등 외부 학습자료(category='library')를 코퍼스에 편입한다. file_watcher 의
PKM 트랙 로직을 재사용하되 dedup 을 file_path 가 아닌 **file_hash** 기준으로 해서
(a) Inbox 중복 (b) `_1`/`카피본` 사본을 1건으로 수렴시킨다(file_watcher 는 path dedup 이라
동일내용 다른경로를 중복 ingest 함). 이후 파이프라인:
  extract(텍스트) → classify → embed/chunk(검색) → markdown(.hwp=pyhwp hwp5html + raster NAS 영속)

실행 (GPU 서버):
  # dry-run (기본) — 무엇이 ingest/skip 될지만 출력
  docker exec hyungi_document_server-fastapi-1 \
    python /app/scripts/backfill_hwp_library.py --subdir Knowledge/Engineering

  # 실제 ingest
  docker exec hyungi_document_server-fastapi-1 \
    python /app/scripts/backfill_hwp_library.py --subdir Knowledge/Engineering --commit
"""

import argparse
import asyncio
import sys
from pathlib import Path

from sqlalchemy import select

from core.config import settings
from core.database import async_session
from core.utils import file_hash
from models.document import Document
from models.queue import enqueue_stage


async def run(subdir: str, commit: bool) -> int:
    nas_root = Path(settings.nas_mount_path)
    scan_root = nas_root / "PKM" / subdir
    if not scan_root.exists():
        print(f"[backfill] scan_root 부재: {scan_root}", file=sys.stderr)
        return 2

    files = sorted(
        p for p in scan_root.rglob("*") if p.is_file() and p.suffix.lower() == ".hwp"
    )
    print(f"[backfill] {scan_root} 하위 .hwp {len(files)}개 발견 / mode={'COMMIT' if commit else 'DRY-RUN'}")

    ingested = skipped_existing = skipped_batchdup = 0
    seen_hashes: set[str] = set()

    async with async_session() as session:
        for fp in files:
            rel_path = str(fp.relative_to(nas_root))
            fhash = file_hash(fp)

            if fhash in seen_hashes:
                print(f"  SKIP(batch-dup)    {rel_path}")
                skipped_batchdup += 1
                continue
            seen_hashes.add(fhash)

            # content-hash dedup (path 무관) — Inbox 중복 + _1/카피본 사본 흡수
            existing = (
                await session.execute(
                    select(Document.id).where(Document.file_hash == fhash).limit(1)
                )
            ).first()
            if existing:
                print(f"  SKIP(exists id={existing[0]})  {rel_path}")
                skipped_existing += 1
                continue

            ingested += 1
            if not commit:
                print(f"  INGEST(dry)        {rel_path}")
                continue

            doc = Document(
                file_path=rel_path,
                file_hash=fhash,
                file_format="hwp",
                file_size=fp.stat().st_size,
                file_type="immutable",
                title=fp.stem,
                source_channel="drive_sync",
                category="library",
                needs_conversion=False,
            )
            session.add(doc)
            await session.flush()
            await enqueue_stage(session, doc.id, "extract")
            print(f"  INGEST id={doc.id}      {rel_path}")

        if commit:
            await session.commit()

    print(
        f"[backfill] done — ingest={ingested} "
        f"skip_existing={skipped_existing} skip_batchdup={skipped_batchdup}"
    )
    return 0


def main() -> int:
    ap = argparse.ArgumentParser(description=__doc__)
    ap.add_argument("--subdir", default="Knowledge/Engineering", help="PKM 하위 스캔 폴더")
    ap.add_argument("--commit", action="store_true", help="실제 ingest (없으면 dry-run)")
    args = ap.parse_args()
    return asyncio.run(run(args.subdir, args.commit))


if __name__ == "__main__":
    sys.exit(main())