/**
 * WebSocket hook for real-time updates from the backend.
 */

import { useEffect, useRef, useCallback, useState } from 'react';

export interface WSMessage {
  type: 'agent_status' | 'log' | 'project_update' | 'pong';
  data: Record<string, unknown>;
}

type WSCallback = (msg: WSMessage) => void;

export function useWebSocket(onMessage: WSCallback) {
  const wsRef = useRef<WebSocket | null>(null);
  const [connected, setConnected] = useState(false);
  const reconnectTimer = useRef<ReturnType<typeof setTimeout> | undefined>(undefined);

  const connect = useCallback(() => {
    const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
    const url = `${protocol}//${window.location.host}/ws/live`;

    const ws = new WebSocket(url);
    wsRef.current = ws;

    ws.onopen = () => {
      setConnected(true);
      // Start ping interval
      const pingInterval = setInterval(() => {
        if (ws.readyState === WebSocket.OPEN) ws.send('ping');
      }, 30000);
      ws.addEventListener('close', () => clearInterval(pingInterval));
    };

    ws.onmessage = (evt) => {
      try {
        const msg = JSON.parse(evt.data) as WSMessage;
        onMessage(msg);
      } catch {
        // ignore parse errors
      }
    };

    ws.onclose = () => {
      setConnected(false);
      // Auto-reconnect after 3s
      reconnectTimer.current = setTimeout(connect, 3000);
    };

    ws.onerror = () => {
      ws.close();
    };
  }, [onMessage]);

  useEffect(() => {
    connect();
    return () => {
      clearTimeout(reconnectTimer.current);
      wsRef.current?.close();
    };
  }, [connect]);

  return { connected };
}