"""CLI entry point: python -m dfgraph path/to/file.dfasm [--port 8420]"""

import argparse
import sys
import threading
import webbrowser
import time
from pathlib import Path

import uvicorn

from dfgraph.server import create_app


def main() -> None:
    parser = argparse.ArgumentParser(
        prog="dfgraph",
        description="Visualise a dfasm dataflow program as an interactive graph.",
    )
    parser.add_argument(
        "file",
        type=Path,
        help="Path to the .dfasm source file to visualise",
    )
    parser.add_argument(
        "--port",
        type=int,
        default=8420,
        help="Port for the web server (default: 8420)",
    )

    args = parser.parse_args()

    if not args.file.exists():
        print(f"Error: file not found: {args.file}", file=sys.stderr)
        sys.exit(1)

    if not args.file.suffix == ".dfasm":
        print(f"Warning: expected .dfasm file, got: {args.file.suffix}", file=sys.stderr)

    app = create_app(args.file.resolve())

    def open_browser():
        time.sleep(1)
        webbrowser.open(f"http://127.0.0.1:{args.port}", new=2)

    thread = threading.Thread(target=open_browser, daemon=True)
    thread.start()

    uvicorn.run(app, host="127.0.0.1", port=args.port, log_level="info")


if __name__ == "__main__":
    main()