class Tracker {
  constructor(options = {}) {
    this.baseUrl = options.baseUrl || '';
    this.timer = null;
    this.startTime = 0;
    this.heartbeatInterval = options.heartbeatInterval || 30000; // 默认30秒发送一次心跳
  }

  init() {
    this.startTime = Date.now();
    this.bindEvents();
    this.startHeartbeat();
  }

  bindEvents() {
    window.addEventListener('beforeunload', this.handleBeforeUnload);
    window.addEventListener('click', this.handleClickEvent);
  }

  startHeartbeat() {
    this.timer = setInterval(() => {
      this.sendData({
        eventType: 'heartbeat',
        duration: Math.round((Date.now() - this.startTime) / 1000),
      }, {heartbeatSeconds: this.heartbeatInterval});
    }, this.heartbeatInterval);
  }

  handleBeforeUnload =  (e) => {
    const data = {
      eventType: 'page_close',
      duration: Math.round((Date.now() - this.startTime) / 1000),
    };
    const payload = JSON.stringify(data);
    if (navigator.sendBeacon) {
      navigator.sendBeacon(this.baseUrl, payload);
    } else {
      this.sendData(payload, {heartbeatSeconds: this.heartbeatInterval});
    }
  };

  handleClickEvent = (event) => {
    const target = event.target;
    if (target.matches('[data-track]')) {
      const trackInfo = {
        eventType: 'button_click',
        elementId: target.id || '无ID',
        elementClass: target.className || '无class',
        text: target.innerText || target.textContent || '',
        timestamp: new Date().toISOString(),
      };
      this.sendData(trackInfo, {heartbeatSeconds: this.heartbeatInterval});
    }
  };

  sendData(data, headers = {}) {
    console.log('上报埋点数据:', data);
    fetch(`${this.baseUrl}`, { method: 'POST', headers: { 'Content-Type': 'application/json' ,...headers}, body: JSON.stringify(data) });
  }

  destroy() {
    window.removeEventListener('beforeunload', this.handleBeforeUnload);
    window.removeEventListener('click', this.handleClickEvent);
    if (this.timer) {
      clearInterval(this.timer);
    }
    this.sendData({
      eventType: 'tracker_destroyed',
      duration: Math.round((Date.now() - this.startTime) / 1000),
    }, {heartbeatSeconds: this.heartbeatInterval});
  }
}

// 使用示例：
// const tracker = new Tracker({ baseUrl: 'https://your-tracking-api.com' });
// tracker.init();

// 暴露给全局或者作为模块导出
window.Tracker = Tracker;