#!/usr/bin/env python3
from __future__ import annotations

import argparse
import json
import zipfile
from pathlib import Path

import pyarrow.parquet as pq


def main() -> int:
    parser = argparse.ArgumentParser(description="Extract one OpenART task from an exported HF-style local dataset.")
    parser.add_argument("--dataset-dir", required=True)
    parser.add_argument("--difficulty", required=True, choices=["mid", "large"])
    parser.add_argument("--task-id", required=True)
    parser.add_argument("--output-dir", required=True)
    args = parser.parse_args()
    dataset = Path(args.dataset_dir)
    metadata = dataset / "data" / args.difficulty / "metadata-00000.parquet"
    rows = pq.read_table(metadata).to_pylist()
    match = next((row for row in rows if row["task_id"] == args.task_id), None)
    if match is None:
        raise SystemExit(f"task not found: {args.task_id}")
    archive_path = dataset / match["bundle_path"]
    prefix = match["bundle_member_prefix"].rstrip("/") + "/"
    out = Path(args.output_dir)
    out.mkdir(parents=True, exist_ok=True)
    with zipfile.ZipFile(archive_path) as archive:
        for member in archive.namelist():
            if not member.startswith(prefix) or member.endswith("/"):
                continue
            target = out / member[len(prefix):]
            target.parent.mkdir(parents=True, exist_ok=True)
            target.write_bytes(archive.read(member))
    print(json.dumps({"task_id": args.task_id, "output_dir": str(out)}, sort_keys=True))
    return 0


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