"""Serve RAG-cut frontend static files (development mode).

Requires the API backend to be running separately:
    python backend/run.py
"""

from __future__ import annotations

import argparse
import http.server
import socketserver
from pathlib import Path

FRONTEND_DIR = Path(__file__).resolve().parent
DEFAULT_API = "http://127.0.0.1:8000"


class FrontendHandler(http.server.SimpleHTTPRequestHandler):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, directory=str(FRONTEND_DIR), **kwargs)


def main() -> None:
    parser = argparse.ArgumentParser(description="Start RAG-cut frontend dev server")
    parser.add_argument("--host", default="127.0.0.1", help="Bind host (default: 127.0.0.1)")
    parser.add_argument("--port", type=int, default=5173, help="Bind port (default: 5173)")
    args = parser.parse_args()

    url = f"http://{args.host}:{args.port}"
    socketserver.TCPServer.allow_reuse_address = True
    with socketserver.TCPServer((args.host, args.port), FrontendHandler) as httpd:
        print(f"Frontend:  {url}")
        print(f"API:       {DEFAULT_API}  (start with: python backend/run.py)")
        print("Press Ctrl+C to stop.")
        httpd.serve_forever()


if __name__ == "__main__":
    main()