#!/usr/bin/env python3
"""Dry-run-first cleanup for old unreferenced derived/cache artifacts."""

from __future__ import annotations

import argparse
import json
from pathlib import Path

from audit_data_operations import build_report
from release_backup_guard import require_confirmation, verify_current_backup

from app.core.config import get_settings
from app.db.session import SessionLocal


CONFIRMATION = "DELETE_STORAGE_ARTIFACTS"


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--storage-root", type=Path)
    parser.add_argument("--minimum-age-days", type=int, default=7)
    parser.add_argument("--max-delete", type=int, default=25)
    parser.add_argument("--apply", action="store_true")
    parser.add_argument("--confirm")
    parser.add_argument("--backup-dir", type=Path)
    parser.add_argument("--backup-max-age-hours", type=float, default=24.0)
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    if args.max_delete < 0:
        raise SystemExit("--max-delete must be greater than or equal to zero")
    storage_root = (args.storage_root or Path(get_settings().storage_root)).resolve()
    with SessionLocal() as db:
        report, candidates = build_report(
            storage_root,
            db,
            minimum_age_days=args.minimum_age_days,
            max_candidate_records=max(args.max_delete, 500),
        )

    blocked_reason = None
    backup = None
    deleted: list[str] = []
    if args.apply:
        require_confirmation(args.confirm, CONFIRMATION)
        if args.backup_dir is None:
            raise RuntimeError("--backup-dir is required with --apply")
        backup = verify_current_backup(
            args.backup_dir,
            max_age_hours=args.backup_max_age_hours,
        )
        if len(candidates) > args.max_delete:
            blocked_reason = (
                f"candidate_count {len(candidates)} exceeds --max-delete {args.max_delete}; "
                "review the dry run and raise the explicit limit"
            )
        else:
            for candidate in candidates:
                candidate.path.unlink()
                deleted.append(candidate.relative_path)

    payload = {
        "schema_version": 1,
        "mode": "apply" if args.apply else "dry-run",
        "storage_root": str(storage_root),
        "minimum_age_days": args.minimum_age_days,
        "max_delete": args.max_delete,
        "candidate_count": len(candidates),
        "candidate_bytes": sum(item.size_bytes for item in candidates),
        "candidates": [item.relative_path for item in candidates],
        "deleted_count": len(deleted),
        "deleted": deleted,
        "blocked_reason": blocked_reason,
        "protected_prefixes": report["cleanup"]["protected_prefixes"],
        "backup": (
            {
                "release_id": backup.release_id,
                "created_at": backup.created_at.isoformat(),
                "age_hours": round(backup.age_hours, 3),
                "git_commit": backup.git_commit,
            }
            if backup
            else None
        ),
    }
    print(json.dumps(payload, indent=2, sort_keys=True))
    return 1 if blocked_reason else 0


if __name__ == "__main__":
    raise SystemExit(main())