#!/usr/bin/env python3
"""Inspect and optionally clean stale job directories.

Default mode is a safe dry-run that reports reclaimable bytes. Pass --apply to
actually remove unreferenced job directories.
"""

from __future__ import annotations

import argparse
import json
from datetime import datetime, timezone
from pathlib import Path

from .metadata_store import MetadataStore
from .storage import Storage


BACKEND_ROOT = Path(__file__).resolve().parents[1]
PROJECT_ROOT = BACKEND_ROOT
WORKSPACE_DIR = PROJECT_ROOT / "service_workspace"
ASSETS_DIR = PROJECT_ROOT / "service_assets"
METADATA_DIR = PROJECT_ROOT / "service_metadata"


def read_asset_meta(path: Path) -> dict:
    try:
        return json.loads(path.read_text(encoding="utf-8"))
    except Exception:
        return {}


def referenced_job_ids() -> set[str]:
    refs: set[str] = set()
    for meta_path in ASSETS_DIR.glob("*/*/meta.json"):
        job_id = read_asset_meta(meta_path).get("job_id") or ""
        if job_id:
            refs.add(job_id)
    return refs


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--max-age-days", type=float, default=0)
    parser.add_argument("--apply", action="store_true", help="Actually delete stale job directories")
    parser.add_argument("--json", type=Path, default=None, help="Write JSON report")
    args = parser.parse_args()

    store = MetadataStore(METADATA_DIR / "app.db")
    storage = Storage(WORKSPACE_DIR)
    known_job_ids = store.job_ids() if store.db_path.exists() else set()
    referenced = referenced_job_ids()
    stale = storage.stale_job_dirs(
        referenced_job_ids=referenced,
        exclude_job_ids=known_job_ids,
        max_age_days=args.max_age_days,
    )

    reclaimable = sum(item["size_bytes"] for item in stale)
    report = {
        "scanned_at": datetime.now(timezone.utc).isoformat(),
        "job_dir_count": len(storage.list_job_ids()),
        "referenced_job_ids": len(referenced),
        "known_job_ids": len(known_job_ids),
        "stale_job_count": len(stale),
        "reclaimable_bytes": reclaimable,
        "max_age_days": args.max_age_days,
        "apply": args.apply,
        "stale_jobs": stale[:200],
    }

    print(json.dumps(report, ensure_ascii=False, indent=2))
    if args.json:
        args.json.write_text(json.dumps(report, ensure_ascii=False, indent=2), encoding="utf-8")

    if args.apply:
        freed = 0
        for item in stale:
            freed += storage.remove_job_dir(item["job_id"])
            store.delete_job(item["job_id"])
        print(f"freed_bytes={freed}")


if __name__ == "__main__":
    main()