// pages/VideoDetails/VideoDetails.js
const api = require('../../utils/api');
const store = require('../../utils/store');
const format = require('../../utils/format');

const POLL_INTERVAL = 1500;
const POLL_MAX = 8;

Page({
  data: {
    code: '',
    owned: false,
    loading: true,
    buying: false,
    VideoTitle: '',
    VideoDetails: '',
    coverUrl: '',
    priceYuan: '',
    playdata: [],
    VideoPlayerSrc: '',
    HiddenVideoControl: true,
    top: 0,
  },

  onLoad(options) {
    const code = options.code;
    if (!code) {
      wx.switchTab({ url: '/pages/kecheng/kecheng' });
      return;
    }
    this.setData({ code: code });
    this.load(code);
  },

  onShow() {
    if (this.data.code && this.data.owned) this.load(this.data.code);
  },

  load(code) {
    api
      .getCourse(code)
      .then((course) => {
        this.setData({
          loading: false,
          owned: course.owned,
          VideoTitle: course.title || '',
          VideoDetails: course.intro || '',
          coverUrl: course.coverUrl || '',
          priceYuan: format.fenToYuan(course.priceFen),
        });
        if (course.owned) this.loadLessons(code);
      })
      .catch((err) => {
        this.setData({ loading: false });
        wx.showToast({ title: err.message || '课程加载失败', icon: 'none' });
        setTimeout(() => wx.switchTab({ url: '/pages/kecheng/kecheng' }), 1500);
      });
  },

  loadLessons(code) {
    api
      .getLessons(code)
      .then((list) => {
        const rows = (list || []).map((item) => ({
          chapterId: item.chapterId,
          playId: item.playId,
          chapterTitle: item.chapterTitle,
          lessonTitle: item.lessonTitle,
          duration: item.duration,
          publishedAt: format.toDateString(item.publishedAt),
          coverUrl: item.coverUrl,
        }));
        this.setData({ playdata: rows });
      })
      .catch((err) => {
        this.setData({ playdata: [] });
        console.warn('[VideoDetails] 课时加载失败', err);
      });
  },

  /** 点课时：向后端换一次性播放地址，视频本身不直接暴露。 */
  onTapLesson(e) {
    const item = this.data.playdata[e.currentTarget.dataset.index];
    if (!item) return;

    wx.showLoading({ title: '加载中', mask: true });
    api
      .getPlayUrl(this.data.code, item.chapterId, item.playId)
      .then((res) => {
        wx.hideLoading();
        this.setData({ VideoPlayerSrc: res.url, HiddenVideoControl: false, top: 420 });
      })
      .catch((err) => {
        wx.hideLoading();
        wx.showToast({ title: err.message || '无法播放', icon: 'none' });
      });
  },

  /** 购买：下单 → 拉起支付 → 轮询订单状态确认发货。 */
  buyNow() {
    if (this.data.buying) return;
    if (typeof wx.requestVirtualPayment !== 'function') {
      wx.showToast({ title: '当前微信版本不支持支付，请升级微信', icon: 'none' });
      return;
    }

    this.setData({ buying: true });
    wx.showLoading({ title: '发起支付', mask: true });

    api
      .createOrder(this.data.code)
      .then((order) => {
        wx.hideLoading();
        return api.requestVirtualPayment(order.payData).then(() => order.outTradeNo);
      })
      .then((outTradeNo) => this.waitForDelivery(outTradeNo))
      .catch((err) => {
        wx.hideLoading();
        this.setData({ buying: false });
        // 用户主动取消不算错误
        if (err && err.errMsg && err.errMsg.indexOf('cancel') >= 0) return;
        wx.showToast({ title: (err && err.message) || '支付失败', icon: 'none' });
      });
  },

  /**
   * 支付成功后权益由服务端发货推送发放，存在秒级延迟，这里轮询确认。
   * 即便轮询全部超时也不会丢单：服务端有定时查单兜底。
   */
  waitForDelivery(outTradeNo) {
    let attempts = 0;
    const poll = () => {
      attempts += 1;
      return api.getOrder(outTradeNo).then((order) => {
        if (order.status === 2) {
          this.setData({ buying: false, owned: true });
          wx.showToast({ title: '购买成功', icon: 'success', mask: true });
          this.load(this.data.code);
          return;
        }
        if (attempts >= POLL_MAX || order.status === 3 || order.status === 4) {
          this.setData({ buying: false });
          wx.showToast({ title: '支付已提交，开通可能稍有延迟', icon: 'none', duration: 3000 });
          return;
        }
        return new Promise((resolve) => setTimeout(resolve, POLL_INTERVAL)).then(poll);
      });
    };
    return poll();
  },

  onShareAppMessage() {
    return { title: '叶雷讲数学', path: '/pages/index/index' };
  },
});