// ==UserScript==
// @name         中国继续医学教育网-刷课助手(免费版)
// @namespace    http://tampermonkey.net/
// @version      1.1.2
// @author       道道龙
// @description  中国继续医学教育网ncme.org.cn专用刷课工具，免费版支持3x/5x倍速播放
// @match        *://*.ncme.org.cn/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_addStyle
// @grant        GM_registerMenuCommand
// @run-at       document-start
// @license MIT
// ==/UserScript==

(function () {
  'use strict';

  var CONFIG = {
    speeds: [3, 5],
    defaultSpeed: 3,
  };

  var state = {
    video: null,
    currentSpeed: CONFIG.defaultSpeed,
    muted: true,
    hookedSet: new Set(),
    uiReady: false,
  };

  // ============================================================
  // 读取记忆的倍速和静音设置
  // ============================================================
  function loadSettings() {
    state.currentSpeed = GM_getValue('__ncme_speed', CONFIG.defaultSpeed);
    state.muted = GM_getValue('__ncme_muted', true);
    console.log('[刷课助手] 读取记忆设置: speed=' + state.currentSpeed + 'x, muted=' + state.muted);
  }

  // ============================================================
  // 核心1：拦截 playbackRate setter（原始脚本同款）
  // ============================================================
  function getPropertyDescriptor(obj, prop) {
    var proto = obj;
    while (proto) {
      var desc = Object.getOwnPropertyDescriptor(proto, prop);
      if (desc) return desc;
      proto = Object.getPrototypeOf(proto);
    }
    return null;
  }

  function hookPlaybackRate(video) {
    if (state.hookedSet.has(video)) return;
    try {
      var originalDesc = getPropertyDescriptor(video, 'playbackRate');
      if (!originalDesc) {
        console.log('[刷课助手] playbackRate描述符不存在');
        return;
      }
      Object.defineProperty(video, 'playbackRate', {
        get: function () {
          if (originalDesc.get) return originalDesc.get.call(video);
          return originalDesc.value;
        },
        set: function (val) {
          if (video._vRate != null && video._vRate != val) return;
          if (originalDesc.set) originalDesc.set.call(video, val);
          else originalDesc.value = val;
        }
      });
      state.hookedSet.add(video);
      console.log('[刷课助手] playbackRate hook成功');
    } catch (e) {
      console.log('[刷课助手] playbackRate hook失败:', e.message);
    }
  }

  function applySpeed(video, speed) {
    if (!video) return;
    hookPlaybackRate(video);
    video._vRate = speed;
    video.playbackRate = speed;
    video.muted = state.muted;
    state.currentSpeed = speed;
    GM_setValue('__ncme_speed', speed); // 记忆
    console.log('[刷课助手] applySpeed: ' + speed + 'x');
  }

  // ============================================================
  // 核心2：拦截 play() 方法（关键！）
  // ============================================================
  function hookPlayMethod() {
    try {
      var proto = HTMLMediaElement.prototype;
      if (proto._playHooked) return;

      var originalPlay = proto.play;

      proto.play = function () {
        var result = originalPlay.apply(this, arguments);
        setTimeout(function () {
          if (state.video && state.currentSpeed) {
            applySpeed(state.video, state.currentSpeed);
            console.log('[刷课助手] play()拦截重新设速=' + state.currentSpeed);
          }
        }, 50);
        return result;
      };

      proto._playHooked = true;
      console.log('[刷课助手] play()方法拦截成功');
    } catch (e) {
      console.log('[刷课助手] play()拦截失败:', e.message);
    }
  }

  // ============================================================
  // 找视频
  // ============================================================
  function findVideo() {
    var videos = document.querySelectorAll('video');
    for (var i = 0; i < videos.length; i++) {
      var v = videos[i];
      if (v.offsetWidth > 100 && v.duration > 0 && !isNaN(v.duration)) {
        return v;
      }
    }
    return videos.length > 0 ? videos[0] : null;
  }

  // ============================================================
  // MutationObserver
  // ============================================================
  function setupObserver() {
    var obs = new MutationObserver(function () {
      var v = findVideo();
      if (v && v !== state.video) {
        state.video = v;
        applySpeed(v, state.currentSpeed);
        if (state.uiReady) showToast('检测到视频，已应用 ' + state.currentSpeed + 'x');
      }
    });
    obs.observe(document.documentElement, { childList: true, subtree: true });
  }

  // ============================================================
  // 轮询
  // ============================================================
  function startPolling() {
    setInterval(function () {
      var v = findVideo();
      if (!v) return;

      if (v !== state.video) {
        state.video = v;
        applySpeed(v, state.currentSpeed);
        console.log('[刷课助手] 发现新视频: ' + v.id);
      } else {
        if (v.playbackRate != state.currentSpeed) {
          applySpeed(v, state.currentSpeed);
          console.log('[刷课助手] 轮询重同步: ' + v.playbackRate + '->' + state.currentSpeed);
        }
      }

      updateProgress(v);
    }, 300);
  }

  // ============================================================
  // 进度
  // ============================================================
  function updateProgress(v) {
    if (!v || !v.duration || isNaN(v.duration)) return;
    var pct = Math.min(100, (v.currentTime / v.duration) * 100);
    var fill = document.getElementById('__ncme_pgf');
    var txt = document.getElementById('__ncme_pgt');
    if (fill) fill.style.width = pct + '%';
    if (txt) {
      var cur = fmt(v.currentTime), tot = fmt(v.duration);
      txt.textContent = v.paused ? ('已暂停 ' + cur + ' / ' + tot) : (cur + ' / ' + tot);
    }
  }

  function fmt(s) {
    s = Math.floor(s);
    return Math.floor(s / 60) + ':' + (s % 60).toString().padStart(2, '0');
  }

  // ============================================================
  // Toast
  // ============================================================
  var toastTimer = null;
  function showToast(msg) {
    var t = document.getElementById('__ncme_toast');
    if (!t) {
      t = document.createElement('div');
      t.id = '__ncme_toast';
      document.body.appendChild(t);
    }
    t.textContent = msg;
    t.className = 'show';
    clearTimeout(toastTimer);
    toastTimer = setTimeout(function () { t.className = 'hide'; }, 3000);
  }

  // ============================================================
  // 切换倍速
  // ============================================================
  function doSetSpeed(speed) {
    state.currentSpeed = speed;
    if (state.video) {
      applySpeed(state.video, speed);
      showToast('已切换至 ' + speed + 'x');
    } else {
      showToast('已选择 ' + speed + 'x，等待视频…');
    }
    updateSpeedButtons(speed);
  }

  function updateSpeedButtons(activeSpeed) {
    var btns = document.querySelectorAll('.__sb[data-v]');
    for (var i = 0; i < btns.length; i++) {
      var v = parseInt(btns[i].getAttribute('data-v'), 10);
      if (v === activeSpeed) btns[i].classList.add('on');
      else btns[i].classList.remove('on');
    }
  }

  // ============================================================
  // UI
  // ============================================================
  function buildUI() {
    if (document.getElementById('__ncme_panel')) return;

    var css = [
      '#__ncme_panel *{box-sizing:border-box;margin:0;padding:0;font-family:"PingFang SC","Microsoft YaHei",sans-serif}',
      '#__ncme_panel{position:fixed;top:20px;left:20px;width:260px;background:#fff;border-radius:14px;box-shadow:0 6px 28px rgba(0,0,0,.10),0 2px 6px rgba(0,0,0,.05);z-index:999999;overflow:hidden;border:1px solid rgba(0,0,0,.06)}',
      '#__ncme_panel .__h{background:linear-gradient(135deg,#2563eb,#1d4ed8);padding:12px 14px;color:#fff;position:relative}',
      '#__ncme_panel .__h .__t{font-size:13px;font-weight:600;display:flex;align-items:center;gap:5px}',
      '#__ncme_panel .__h .__p{font-size:10px;opacity:.7;margin-top:2px}',
      '#__ncme_panel .__h .__tag{position:absolute;top:10px;right:14px;background:rgba(255,255,255,.9);border-radius:20px;padding:2px 7px;font-size:9px;color:#dc2626;font-weight:700}',
      '#__ncme_panel .__bd{padding:12px 14px}',
      '#__ncme_panel .__lb{font-size:10px;color:#999;margin-bottom:6px;font-weight:500}',
      '#__ncme_panel .__sp{display:flex;gap:5px;margin-bottom:10px}',
      '#__ncme_panel .__sb{flex:1;height:34px;border:1.5px solid #e5e7eb;border-radius:7px;background:#fff;cursor:pointer;font-size:13px;font-weight:600;color:#374151;transition:all .2s;position:relative;display:flex;align-items:center;justify-content:center}',
      '#__ncme_panel .__sb:hover{border-color:#2563eb;color:#2563eb}',
      '#__ncme_panel .__sb.on{border-color:#2563eb;background:#eff6ff;color:#2563eb}',
      '#__ncme_panel .__sb .__lk{display:none;position:absolute;top:-5px;right:-5px;width:14px;height:14px;background:#f59e0b;border-radius:50%;font-size:8px;color:#fff;align-items:center;justify-content:center}',
      '#__ncme_panel .__sb.lk{opacity:.5;cursor:not-allowed}',
      '#__ncme_panel .__sb.lk .__lk{display:flex}',
      '#__ncme_panel .__ts{display:flex;gap:6px;margin-bottom:10px}',
      '#__ncme_panel .__tg{flex:1;display:flex;align-items:center;gap:4px;cursor:pointer;padding:5px 7px;border-radius:7px;border:1px solid #e5e7eb;background:#fff;transition:all .2s;font-size:10px;color:#666}',
      '#__ncme_panel .__tg:hover{border-color:#2563eb;color:#2563eb}',
      '#__ncme_panel .__tg.on{border-color:#16a34a;background:#f0fdf4;color:#16a34a}',
      '#__ncme_panel .__tg .__d{width:5px;height:5px;border-radius:50%;background:#ccc}',
      '#__ncme_panel .__tg.on .__d{background:#16a34a}',
      '#__ncme_panel .__pg{margin-bottom:10px}',
      '#__ncme_panel .__pgbar{height:3px;background:#e5e7eb;border-radius:2px;overflow:hidden}',
      '#__ncme_panel .__pgf{height:100%;background:linear-gradient(90deg,#2563eb,#1d4ed8);border-radius:2px;transition:width .8s ease;width:0%}',
      '#__ncme_panel .__pgt{font-size:10px;color:#999;margin-top:3px;text-align:right}',
      '#__ncme_panel .__note{padding:8px 14px;background:#f9fafb;border-top:1px solid #f0f0f0;font-size:10px;color:#333;text-align:center;line-height:1.5}',
      '#__ncme_toast{position:fixed;top:20px;left:300px;background:rgba(0,0,0,.72);color:#fff;padding:7px 14px;border-radius:7px;font-size:12px;z-index:9999999;pointer-events:none;transition:opacity .3s;display:none}',
      '#__ncme_toast.show{display:block;opacity:1}',
      '#__ncme_toast.hide{opacity:0}'
    ].join('');

    var styleEl = document.createElement('style');
    styleEl.textContent = css;
    document.head.appendChild(styleEl);

    var speedBtnsHtml = CONFIG.speeds.map(function (v) {
      return '<button class="__sb' + (v === state.currentSpeed ? ' on' : '') + '" data-v="' + v + '">' + v + 'x</button>';
    }).join('');

    var panel = document.createElement('div');
    panel.id = '__ncme_panel';
    panel.innerHTML = [
      '<div class="__h">',
        '<div class="__t"><span>▶</span> 刷课助手</div>',
        '<div class="__p">中国继续医学教育网</div>',
        '<span class="__tag">免费版</span>',
      '</div>',
      '<div class="__bd">',
        '<div class="__lb">倍速播放</div>',
        '<div class="__sp" id="__sp">' + speedBtnsHtml + '<button class="__sb lk" data-v="10">10x<span class="__lk">🔒</span></button></div>',
        '<div class="__lb">功能</div>',
        '<div class="__ts">',
          '<div class="__tg' + (state.muted ? ' on' : '') + '" id="__mute"><span class="__d"></span>静音</div>',
        '</div>',
        '<div class="__pg">',
          '<div class="__pgbar"><div class="__pgf" id="__ncme_pgf"></div></div>',
          '<div class="__pgt" id="__ncme_pgt">等待视频…</div>',
        '</div>',
      '</div>',
      '<div class="__note">⚠ 免费版请手动播放/切换下一节<br>代刷8元 👉 微信 wkds995</div>'
    ].join('');

    document.body.appendChild(panel);

    var btns = panel.querySelectorAll('.__sb[data-v]');
    for (var i = 0; i < btns.length; i++) {
      (function (btn) {
        btn.addEventListener('click', function () {
          var speed = parseInt(btn.getAttribute('data-v'), 10);
          doSetSpeed(speed);
        });
      })(btns[i]);
    }

    var lockBtn = panel.querySelector('.__sb.lk');
    if (lockBtn) lockBtn.addEventListener('click', function () { showToast('10x为专业版功能，联系微信 wkds995'); });

    var muteBtn = panel.querySelector('#__mute');
    if (muteBtn) {
      muteBtn.addEventListener('click', function () {
        state.muted = !state.muted;
        muteBtn.className = '__tg ' + (state.muted ? 'on' : '');
        if (state.video) state.video.muted = state.muted;
        GM_setValue('__ncme_muted', state.muted); // 记忆
        showToast(state.muted ? '静音已开启' : '静音已关闭');
      });
    }

    GM_registerMenuCommand('🔧 刷课助手设置', function () {
      var el = document.getElementById('__ncme_panel');
      if (el) el.scrollIntoView({ behavior: 'smooth' });
    });

    state.uiReady = true;
  }

  // ============================================================
  // 启动
  // ============================================================
  function bootstrap() {
    console.log('[刷课助手] 启动');
    loadSettings();   // 先读记忆
    hookPlayMethod();
    setupObserver();
    startPolling();
    buildUI();
    showToast('刷课助手已就绪，请进入课程页面');
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', bootstrap);
  } else {
    bootstrap();
  }

})();