"""CLI entry point: python -m monitor [path/to/file.dfasm]"""

import argparse
import sys
from pathlib import Path

from monitor.backend import SimulationBackend
from monitor.commands import LoadCmd
from monitor.repl import MonitorREPL


def main() -> None:
    parser = argparse.ArgumentParser(
        prog="monitor",
        description="Interactive OR1 dataflow CPU simulation monitor.",
    )
    parser.add_argument(
        "file",
        nargs="?",
        type=Path,
        default=None,
        help="Optional .dfasm file to load on startup",
    )
    parser.add_argument(
        "--web",
        action="store_true",
        help="Start web server instead of CLI REPL",
    )
    parser.add_argument(
        "--port",
        type=int,
        default=8421,
        help="Port for web server (default: 8421)",
    )

    args = parser.parse_args()

    backend = SimulationBackend()
    backend.start()

    try:
        if args.web:
            import uvicorn
            from monitor.server import create_app

            app = create_app(backend)
            if args.file is not None:
                if not args.file.exists():
                    print(f"Error: file not found: {args.file}", file=sys.stderr)
                    sys.exit(1)
                source = args.file.resolve().read_text()
                backend.send_command(LoadCmd(source=source), timeout=10.0)
            uvicorn.run(app, host="127.0.0.1", port=args.port, log_level="info")
        else:
            repl = MonitorREPL(backend)

            if args.file is not None:
                if not args.file.exists():
                    print(f"Error: file not found: {args.file}", file=sys.stderr)
                    sys.exit(1)
                repl.do_load(str(args.file.resolve()))

            repl.cmdloop()
    finally:
        backend.stop()


if __name__ == "__main__":
    main()