YD_WeChatApplet/subpackage/teacher/resource-detail/resource-detail.js

const utils = require("../../../utils/utils");

Page({
  data: {
    title: "音乐",
    data: {},
    playlist: [],
    currentIndex: 0,
    value: "00:00",
    duration: "00:00",
    durationSeconds: 1,
    sliderValue: 0,
    percent: 0,
    isPlay: false,
    isSingleLoop: false,
    isShow: false,
    isClosing: false
  },

  onLoad(options) {
    let current = {};
    try {
      current = JSON.parse(decodeURIComponent(options.data || "{}"));
    } catch (error) {
      console.error("资源参数解析失败", error);
    }

    this.setData({
      data: current,
      playlist: current.resourceUrl ? [current] : [],
      title: current.id == 1 ? "口令" : "音乐"
    });

    this.createAudioContext();
    if (current.resourceUrl) {
      this.loadTrack(current, false);
    }

    const eventChannel = this.getOpenerEventChannel && this.getOpenerEventChannel();
    if (eventChannel && eventChannel.on) {
      eventChannel.on("setPlaylist", ({ playlist = [], currentIndex = 0 }) => {
        if (!playlist.length) return;
        const safeIndex = Math.min(Math.max(Number(currentIndex) || 0, 0), playlist.length - 1);
        this.setData({ playlist, currentIndex: safeIndex, data: playlist[safeIndex] }, () => {
          this.probeAudioDuration(playlist[safeIndex]);
        });
      });
    }
  },

  createAudioContext() {
    this.audioCtx = wx.getBackgroundAudioManager();
    this.audioCache = {};
    this.audioDurationCache = {};
    this.recoveryAttempted = {};
    this.loadedTrackUrl = "";
    this.audioHandlers = {
      canplay: () => this.updateProgress(),
      timeUpdate: () => {
        this.clearWaitingTimer();
        this.updateProgress();
      },
      waiting: () => this.handleAudioWaiting(),
      play: () => this.setData({ isPlay: true }),
      pause: () => this.setData({ isPlay: false }),
      stop: () => this.setData({ isPlay: false }),
      ended: () => {
        if (this.data.isSingleLoop) {
          this.audioCtx.seek(0);
          this.audioCtx.play();
        } else {
          this.changeTrack(1, true);
        }
      },
      error: (error) => this.handleAudioError(error),
      prev: () => this.playPrevious(),
      next: () => this.playNext()
    };

    this.audioCtx.onCanplay(this.audioHandlers.canplay);
    this.audioCtx.onTimeUpdate(this.audioHandlers.timeUpdate);
    this.audioCtx.onWaiting(this.audioHandlers.waiting);
    this.audioCtx.onPlay(this.audioHandlers.play);
    this.audioCtx.onPause(this.audioHandlers.pause);
    this.audioCtx.onStop(this.audioHandlers.stop);
    this.audioCtx.onEnded(this.audioHandlers.ended);
    this.audioCtx.onError(this.audioHandlers.error);
    this.audioCtx.onPrev(this.audioHandlers.prev);
    this.audioCtx.onNext(this.audioHandlers.next);
  },

  loadTrack(track, autoplay = true) {
    if (!track || !track.resourceUrl || !this.audioCtx) return;
    this.cancelPendingDownload();
    this.clearWaitingTimer();
    const cachedDuration = Number(this.audioDurationCache[track.resourceUrl]) || 0;
    this.setData({
      data: track,
      value: "00:00",
      duration: cachedDuration ? utils.formatTimeStr(cachedDuration) : "00:00",
      durationSeconds: cachedDuration || 1,
      sliderValue: 0,
      percent: 0,
      isPlay: false
    });
    if (!cachedDuration) this.probeAudioDuration(track);
    if (!autoplay) return;

    const playableUrl = this.audioCache[track.resourceUrl] || track.resourceUrl;
    this.playAudioSource(track, playableUrl, 0);
  },

  playAudioSource(track, playableUrl, startTime = 0) {
    if (!this.audioCtx || !track || !playableUrl) return;
    this.audioCtx.title = track.resourceName || this.data.title || "音频资源";
    this.audioCtx.epname = this.data.title || "教学资源";
    this.audioCtx.singer = "跃动";
    this.audioCtx.startTime = Math.max(Number(startTime) || 0, 0);
    this.loadedTrackUrl = track.resourceUrl;
    this.audioCtx.src = playableUrl;
  },

  handleAudioWaiting() {
    if (this.waitingTimer || this.downloadTask || !this.data.data.resourceUrl) return;
    const trackUrl = this.data.data.resourceUrl;
    const resumeTime = Number(this.audioCtx.currentTime) || 0;
    this.waitingTimer = setTimeout(() => {
      this.waitingTimer = null;
      if (this.data.data.resourceUrl === trackUrl && !this.audioCache[trackUrl]) {
        this.downloadAndPlay(this.data.data, Number(this.audioCtx.currentTime) || resumeTime);
      }
    }, 5000);
  },

  handleAudioError(error = {}) {
    console.error("音频播放失败", {
      errCode: error.errCode,
      errMsg: error.errMsg,
      url: this.data.data.resourceUrl
    });
    this.clearWaitingTimer();
    this.setData({ isPlay: false });

    const track = this.data.data;
    const trackUrl = track && track.resourceUrl;
    if (this.downloadTask) return;
    if (trackUrl && !this.audioCache[trackUrl] && !this.recoveryAttempted[trackUrl]) {
      this.downloadAndPlay(track, Number(this.audioCtx.currentTime) || 0);
      return;
    }

    const message = Number(error.errCode) === 10003
      ? "音频文件响应异常，请检查文件配置"
      : "音频加载失败，请稍后重试";
    wx.showToast({ title: message, icon: "none" });
  },

  downloadAndPlay(track, resumeTime = 0) {
    if (!track || !track.resourceUrl || this.downloadTask) return;
    const originalUrl = track.resourceUrl;
    this.recoveryAttempted[originalUrl] = true;
    const downloadState = { canceled: false, url: originalUrl };
    this.downloadState = downloadState;
    wx.showLoading({ title: "音频加载中", mask: false });

    this.downloadTask = wx.downloadFile({
      url: originalUrl,
      success: (result) => {
        if (downloadState.canceled) return;
        if (result.statusCode !== 200 || !result.tempFilePath) {
          this.showDownloadError();
          return;
        }
        this.audioCache[originalUrl] = result.tempFilePath;
        if (this.data.data.resourceUrl === originalUrl) {
          this.playAudioSource(track, result.tempFilePath, resumeTime);
        }
      },
      fail: (error) => {
        if (downloadState.canceled) return;
        console.error("音频下载失败", error);
        this.showDownloadError();
      },
      complete: () => {
        if (this.downloadState === downloadState) {
          this.downloadTask = null;
          this.downloadState = null;
          wx.hideLoading();
        }
      }
    });
  },

  showDownloadError() {
    this.setData({ isPlay: false });
    wx.showToast({ title: "长音频加载失败，请检查网络或文件配置", icon: "none" });
  },

  clearWaitingTimer() {
    if (!this.waitingTimer) return;
    clearTimeout(this.waitingTimer);
    this.waitingTimer = null;
  },

  cancelPendingDownload() {
    if (!this.downloadTask) return;
    if (this.downloadState) {
      this.downloadState.canceled = true;
      delete this.recoveryAttempted[this.downloadState.url];
    }
    this.downloadTask.abort();
    this.downloadTask = null;
    this.downloadState = null;
    wx.hideLoading();
  },

  updateProgress() {
    if (!this.audioCtx || this.isSeeking) return;
    const currentTime = Number(this.audioCtx.currentTime) || 0;
    const audioDuration = Number(this.audioCtx.duration) || 0;
    const knownDuration = this.data.durationSeconds > 1 ? this.data.durationSeconds : 0;
    const duration = audioDuration || knownDuration;
    this.setData({
      value: utils.formatTimeStr(currentTime),
      duration: duration ? utils.formatTimeStr(duration) : this.data.duration,
      durationSeconds: duration || 1,
      sliderValue: Math.min(currentTime, duration || 1),
      percent: duration ? Math.min((currentTime / duration) * 100, 100) : 0
    });
  },

  probeAudioDuration(track) {
    if (!track || !track.resourceUrl || !wx.createInnerAudioContext) return;
    this.destroyDurationProbe();

    const trackUrl = track.resourceUrl;
    const probe = wx.createInnerAudioContext();
    this.durationProbe = probe;
    probe.autoplay = false;
    probe.obeyMuteSwitch = false;

    const syncDuration = () => {
      if (this.durationProbe !== probe || this.data.data.resourceUrl !== trackUrl) return false;
      const duration = Number(probe.duration) || 0;
      if (duration <= 0) return false;
      this.audioDurationCache[trackUrl] = duration;
      this.setData({
        duration: utils.formatTimeStr(duration),
        durationSeconds: duration
      });
      this.destroyDurationProbe();
      return true;
    };

    probe.onCanplay(() => {
      if (syncDuration()) return;
      [200, 500, 1000, 2000].forEach((delay) => {
        const timer = setTimeout(syncDuration, delay);
        this.durationProbeTimers.push(timer);
      });
    });
    probe.onError((error) => {
      console.warn("音频时长读取失败", error);
      this.destroyDurationProbe();
    });
    this.durationProbeTimers = [];
    probe.src = trackUrl;
  },

  destroyDurationProbe() {
    (this.durationProbeTimers || []).forEach((timer) => clearTimeout(timer));
    this.durationProbeTimers = [];
    if (!this.durationProbe) return;
    this.durationProbe.destroy();
    this.durationProbe = null;
  },

  btnCilck() {
    if (!this.audioCtx || !this.data.data.resourceUrl) return;
    if (this.data.isPlay) {
      this.audioCtx.pause();
    } else if (this.loadedTrackUrl !== this.data.data.resourceUrl) {
      this.loadTrack(this.data.data, true);
    } else {
      this.audioCtx.play();
    }
  },

  playPrevious() {
    this.changeTrack(-1, true);
  },

  playNext() {
    this.changeTrack(1, true);
  },

  changeTrack(step, autoplay) {
    const { playlist, currentIndex } = this.data;
    if (!playlist.length) return;
    const nextIndex = (currentIndex + step + playlist.length) % playlist.length;
    this.setData({ currentIndex: nextIndex }, () => this.loadTrack(playlist[nextIndex], autoplay));
  },

  selectTrack(e) {
    const index = Number(e.currentTarget.dataset.index);
    if (!Number.isInteger(index) || !this.data.playlist[index]) return;
    this.setData({ currentIndex: index }, () => {
      this.loadTrack(this.data.playlist[index], true);
      this.hideList();
    });
  },

  toggleLoop() {
    const isSingleLoop = !this.data.isSingleLoop;
    this.setData({ isSingleLoop });
    wx.showToast({ title: isSingleLoop ? "单曲循环" : "列表循环", icon: "none" });
  },

  onSliderChanging(e) {
    const seconds = Number(e.detail.value) || 0;
    this.isSeeking = true;
    this.setData({
      sliderValue: seconds,
      value: utils.formatTimeStr(seconds),
      percent: this.data.durationSeconds ? (seconds / this.data.durationSeconds) * 100 : 0
    });
  },

  onSliderChange(e) {
    const seconds = Number(e.detail.value) || 0;
    if (!this.audioCtx || !this.data.data.resourceUrl) return;

    if (this.loadedTrackUrl !== this.data.data.resourceUrl) {
      this.loadTrack(this.data.data, true);
    }
    this.audioCtx.seek(seconds);
    this.setData({
      sliderValue: seconds,
      value: utils.formatTimeStr(seconds),
      percent: this.data.durationSeconds ? (seconds / this.data.durationSeconds) * 100 : 0
    });

    if (this.seekTimer) clearTimeout(this.seekTimer);
    this.seekTimer = setTimeout(() => {
      this.isSeeking = false;
      this.updateProgress();
      this.seekTimer = null;
    }, 350);
  },

  showList() {
    if (this.closeTimer) {
      clearTimeout(this.closeTimer);
      this.closeTimer = null;
    }
    this.setData({ isShow: true, isClosing: false });
  },

  hideList() {
    if (!this.data.isShow || this.data.isClosing) return;
    this.setData({ isClosing: true });
    this.closeTimer = setTimeout(() => {
      this.setData({ isShow: false, isClosing: false });
      this.closeTimer = null;
    }, 240);
  },

  preventClose() {},

  onUnload() {
    if (this.closeTimer) clearTimeout(this.closeTimer);
    if (this.seekTimer) clearTimeout(this.seekTimer);
    this.clearWaitingTimer();
    this.cancelPendingDownload();
    this.destroyDurationProbe();
    if (this.audioCtx) {
      this.audioCtx.stop();
      const handlers = this.audioHandlers || {};
      if (this.audioCtx.offCanplay) this.audioCtx.offCanplay(handlers.canplay);
      if (this.audioCtx.offTimeUpdate) this.audioCtx.offTimeUpdate(handlers.timeUpdate);
      if (this.audioCtx.offWaiting) this.audioCtx.offWaiting(handlers.waiting);
      if (this.audioCtx.offPlay) this.audioCtx.offPlay(handlers.play);
      if (this.audioCtx.offPause) this.audioCtx.offPause(handlers.pause);
      if (this.audioCtx.offStop) this.audioCtx.offStop(handlers.stop);
      if (this.audioCtx.offEnded) this.audioCtx.offEnded(handlers.ended);
      if (this.audioCtx.offError) this.audioCtx.offError(handlers.error);
      if (this.audioCtx.offPrev) this.audioCtx.offPrev(handlers.prev);
      if (this.audioCtx.offNext) this.audioCtx.offNext(handlers.next);
      this.audioCtx = null;
    }
  }
});