import emitter from '@/utils/mitt';

type WebSocketInternalOptions = {
  fullUrl: string;
  reconnectInterval?: number;
};

let websocket: WebSocket | null = null;
let reconnectTimer: any = null;
let isManualClose = false;

/** 初始化WebSocket */
export function initWebSocket(options: WebSocketInternalOptions) {
  const { fullUrl, reconnectInterval = 3000 } = options;

  // 关闭已有连接
  if (websocket) {
    websocket.close();
  }

  if (!('WebSocket' in window)) {
    console.error('当前浏览器不支持WebSocket');
    return;
  }

  try {
    websocket = new WebSocket(fullUrl);

    // 连接成功
    websocket.onopen = () => {
      clearTimeout(reconnectTimer!);
      isManualClose = false;
      console.log('WebSocket 连接成功');
    };

    // 接收消息，自动解析按 msgType 分发事件
    websocket.onmessage = (event) => {
      try {
        const rawMsg = JSON.parse(event.data);
        const msgType = rawMsg.msgType;
        emitter.emit(msgType, rawMsg);
      } catch (err) {
        console.error('WebSocket消息解析失败：', err);
      }
    };

    // 连接异常
    websocket.onerror = (error) => {
      console.error('WebSocket 连接异常：', error);
      startReconnect(() => initWebSocket(options), reconnectInterval);
    };

    // 连接关闭
    websocket.onclose = () => {
      console.log('WebSocket 连接关闭');
      if (!isManualClose) {
        startReconnect(() => initWebSocket(options), reconnectInterval);
      }
    };
  } catch (error) {
    console.error('WebSocket 创建失败：', error);
    startReconnect(() => initWebSocket(options), reconnectInterval);
  }
}

/** 发送ws消息 */
export function sendWebSocketMessage(message: any): boolean {
  if (websocket && websocket.readyState === WebSocket.OPEN) {
    websocket.send(JSON.stringify(message));
    return true;
  }
  console.error('WebSocket未连接，发送失败');
  return false;
}

/** 手动关闭ws（登出时调用） */
export function closeWebSocket(): void {
  isManualClose = true;
  if (reconnectTimer) {
    clearTimeout(reconnectTimer);
  }
  websocket?.close();
  websocket = null;
}

/** 获取当前连接状态 */
export function getWebSocketState(): number | null {
  return websocket?.readyState || null;
}

// 内部重连私有方法
function startReconnect(connectCallback: () => void, interval: number): void {
  if (reconnectTimer) {
    clearTimeout(reconnectTimer);
  }
  reconnectTimer = setTimeout(connectCallback, interval);
}