// WebSocket状態管理の基本パターン
class WebSocketManager {
  constructor(url) {
    this.url = url;
    this.ws = null;
    this.reconnectAttempts = 0;
    this.maxReconnectAttempts = 3;
  }

  connect() {
    if (this.ws?.readyState === WebSocket.OPEN) {
      console.log('Already connected');
      return;
    }

    this.ws = new WebSocket(this.url);
    
    this.ws.onopen = () => {
      console.log('Connected (ReadyState: 1)');
      this.reconnectAttempts = 0;
    };
    
    this.ws.onmessage = (event) => {
      console.log('Message received:', event.data);
    };
    
    this.ws.onclose = (event) => {
      console.log(`Closed (Code: ${event.code}, ReadyState: 3)`);
      this.handleReconnect(event.code);
    };
    
    this.ws.onerror = () => {
      console.log('Error occurred');
    };
  }

  send(message) {
    if (this.ws?.readyState === WebSocket.OPEN) {
      this.ws.send(message);
    } else {
      console.log('Cannot send: WebSocket not open');
    }
  }

  handleReconnect(closeCode) {
    // Close code による再接続判断
    if (closeCode === 1000 || closeCode === 1001) {
      return; // 正常終了、再接続不要
    }
    
    if (this.reconnectAttempts < this.maxReconnectAttempts) {
      setTimeout(() => {
        console.log('Attempting reconnect...');
        this.reconnectAttempts++;
        this.connect();
      }, 1000 * Math.pow(2, this.reconnectAttempts)); // 指数バックオフ
    }
  }
}