"""Main entry point for the Terminal Chat application."""

import asyncio
import os
import argparse

from chatapp.models import UserConnection
from chatapp.chat_server import ChatServer
from chatapp.ui import TerminalChatApp
from chatapp.ssh_server import start_ssh_server


# Global chat server instance
chat_server = ChatServer()


async def start_terminal_chat(username: str):
    """Start a TerminalChatApp for a single local user.

    This creates a UserConnection attached to an asyncio.Queue, registers
    the user on the chat_server, runs the textual app asynchronously, and
    ensures the user is removed when the app exits.
    """
    message_queue = asyncio.Queue()
    user_conn = UserConnection(username, message_queue)
    chat_server.add_user(username, user_conn)

    try:
        app = TerminalChatApp(username, message_queue, chat_server)
        await app.run_async()
    finally:
        chat_server.remove_user(username)


def main():
    """Main entry point with argument parsing."""
    parser = argparse.ArgumentParser(description="Run Terminal Chat locally or via SSH")
    parser.add_argument("--ssh", action="store_true", help="Start SSH server mode")
    parser.add_argument("--host", default="0.0.0.0", help="Host to bind SSH server to (default: 0.0.0.0)")
    parser.add_argument("--port", type=int, default=8022, help="Port for SSH server (default: 8022)")
    parser.add_argument("--username", help="Username to use for the local terminal chat")
    args = parser.parse_args()

    if args.ssh:
        # SSH server mode
        try:
            asyncio.run(start_ssh_server(args.host, args.port, chat_server))
        except KeyboardInterrupt:
            print("\nSSH server stopped")
            raise SystemExit(0)
        except Exception as exc:
            print(f"Error starting SSH server: {exc}")
            raise SystemExit(1)
    else:
        # Local terminal mode
        username = args.username or os.getenv("USER") or os.getenv("USERNAME")
        if not username:
            try:
                username = input("Enter username: ").strip()
            except KeyboardInterrupt:
                raise SystemExit(1)

        if not username:
            print("A username is required to start the chat.")
            raise SystemExit(1)

        try:
            asyncio.run(start_terminal_chat(username))
        except Exception as exc:
            print(f"Error while running Terminal Chat: {exc}")
            raise


if __name__ == "__main__":
    main()