"""REAPER .rpp song generator — thin CLI wrapper around compose.main().

Usage:
    python scripts/generate.py --bpm 95 --key Am --output output/song.rpp --seed 42
"""

from __future__ import annotations

import argparse
import sys
from pathlib import Path

_ROOT = Path(__file__).parent.parent
sys.path.insert(0, str(_ROOT))
import compose


def main() -> None:
    parser = argparse.ArgumentParser(description="Generate a REAPER .rpp reggaeton song.")
    parser.add_argument("--bpm", type=float, default=95, help="BPM (default: 95)")
    parser.add_argument("--key", default="Am", help="Musical key (default: Am)")
    parser.add_argument(
        "--output", default="output/song.rpp", help="Output .rpp path (default: output/song.rpp)"
    )
    parser.add_argument("--seed", type=int, default=42, help="Random seed (default: 42)")
    parser.add_argument(
        "--validate", action="store_true", help="Run validator after generation"
    )
    args = parser.parse_args()

    # BPM validation
    if args.bpm <= 0:
        raise ValueError("bpm must be > 0")

    # Ensure output directory exists
    output_path = Path(args.output)
    output_path.parent.mkdir(parents=True, exist_ok=True)

    # Delegate to compose.main() — set sys.argv so compose's argparse works
    sys.argv = [
        sys.argv[0],
        "--bpm", str(args.bpm),
        "--key", args.key,
        "--output", str(output_path),
        "--seed", str(args.seed),
    ]
    compose.main()

    # Post-generation validation
    if args.validate:
        from src.validator.rpp_validator import validate_rpp_output

        errors = validate_rpp_output(str(output_path), expected_bpm=args.bpm, expected_bars=52)
        if errors:
            print("Validation errors:", file=sys.stderr)
            for err in errors:
                print(f"  - {err}", file=sys.stderr)
            sys.exit(1)
        print("Validation passed.", file=sys.stderr)


if __name__ == "__main__":
    main()