#!/usr/bin/env python3
"""
CLI to run ETL: NetCDF trajectory file → Arrow blocks + metadata.

Usage:
  python -m scripts.run_etl path/to/trajectories.nc
  python -m scripts.run_etl path/to/file.nc --sim-id my_run
  python -m scripts.run_etl file.nc --out-dir /path/to/backend/data --write-json
"""

from __future__ import annotations

import argparse
from pathlib import Path


def main():
    parser = argparse.ArgumentParser(description="ETL: NetCDF trajectories → Arrow blocks")
    parser.add_argument("nc_path", type=str, help="Path to input .nc file")
    parser.add_argument(
        "--out-dir",
        type=str,
        default=None,
        help="Output base directory (default: backend/data)",
    )
    parser.add_argument(
        "--sim-id",
        type=str,
        default="default",
        help="Simulation ID (default: default)",
    )
    parser.add_argument(
        "--write-json",
        action="store_true",
        help="Also write block_*.json (for backward compat)",
    )
    args = parser.parse_args()

    if args.out_dir is None:
        out_dir = Path(__file__).resolve().parent.parent / "data"
    else:
        out_dir = Path(args.out_dir)

    from etl.pipeline import run_etl

    nc_path = Path(args.nc_path)
    if not nc_path.exists():
        raise SystemExit(f"File not found: {nc_path}")

    print(f"ETL: {nc_path} → {out_dir / 'simulations' / args.sim_id}")
    meta = run_etl(nc_path, out_dir, sim_id=args.sim_id, write_json=args.write_json)
    print(f"  num_particles={meta['num_particles']}, num_steps={meta['num_steps']}, num_blocks={meta['num_blocks']}")
    print("Done.")


if __name__ == "__main__":
    main()