"""Explicit optional code execution using existing compilers; no installs/downloads."""
import argparse
import datetime
import json
from pathlib import Path
from verify import verify

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--tsc", required=True, type=Path)
    parser.add_argument("--output", required=True, type=Path)
    args = parser.parse_args()
    if args.output.exists() or args.output.is_symlink():
        parser.error("output already exists; choose a new directory")
    if not args.tsc.is_file():
        parser.error("--tsc must name an existing TypeScript compiler; nothing is installed")
    args.output.mkdir(parents=True, exist_ok=False)
    started = datetime.datetime.now(datetime.timezone.utc).isoformat()
    try:
        verify(args.output, args.tsc.resolve())
    finally:
        receipt = args.output / "RESULTS.json"
        if receipt.is_file():
            report = json.loads(receipt.read_text())
            report["executed_at_utc"] = started
            receipt.write_text(json.dumps(report, ensure_ascii=False, indent=2) + "\n")
