const EXIT_THRESHOLD = 80;
const FAST_SWIPE_VELOCITY = 0.5;

// 加载文案库
const LOADING_QUOTES = [
  "正在翻阅《古今集成》...",
  "于诗书中寻觅意境...",
  "聆听平仄的韵律...",
  "在字里行间游走...",
  "采撷一缕清风入名...",
  "品味楚辞的芬芳...",
  "捕捉诗经的灵光...",
  "与古人隔空对话..."
];

Page({
  isDragging: false,
  isExiting: false,
  startTime: 0,
  startX: 0,
  startY: 0,
  lastX: 0,
  loadingQuoteTimer: null,

  data: {
    nameList: [],
    currentIndex: 0,
    isLoading: true,
    isFlipped: false,
    keyword: '清冷',
    mode: 'classic',
    modeName: '拾遗',
    surname: '',
    loadingQuote: '正在翻阅《古今集成》...',
    
    // 动画控制
    translateX: 0,
    rotate: 0,
    opacity: 1,
    transition: 'none',
    
    cardKey: 0,
    collectedNames: [],
    showCollection: false,
    
    // 海报相关
    showPoster: false,
    posterNameChars: []
  },

  onLoad(options) {
    // 解码 URL 参数
    const keyword = options.keyword ? decodeURIComponent(options.keyword) : this.data.keyword;
    const mode = options.mode || 'classic';
    const surname = options.surname ? decodeURIComponent(options.surname) : '';
    
    // 模式名称映射
    const modeNameMap = {
      'baby': '宝宝',
      'persona': '人设',
      'classic': '拾遗'
    };
    
    this.setData({ 
      keyword, 
      mode, 
      surname,
      modeName: modeNameMap[mode] || '拾遗',
      isLoading: true
    });
    
    // 启动文案轮换
    this.startLoadingQuoteRotation();
    
    // 分批加载：先请求2个，再静默加载剩余
    this.fetchNamesBatch(keyword, mode, surname);
  },

  onUnload() {
    // 清理定时器
    if (this.loadingQuoteTimer) {
      clearInterval(this.loadingQuoteTimer);
      this.loadingQuoteTimer = null;
    }
  },

  onShow() {
    // 每次显示页面时加载收藏列表
    this.loadCollectedNames();
  },

  // 从后端加载收藏列表
  loadCollectedNames() {
    const openid = 'test_openid'; // 实际应从登录获取
    const apiBaseUrl = getApp().globalData.apiBaseUrl;
    wx.request({
      url: `${apiBaseUrl}/api/favorites/list`,
      data: { openid },
      success: (res) => {
        if (res.data && res.data.success) {
          this.setData({ collectedNames: res.data.data || [] });
        }
      }
    });
  },

  // 启动加载文案轮换
  startLoadingQuoteRotation() {
    let index = 0;
    this.loadingQuoteTimer = setInterval(() => {
      index = (index + 1) % LOADING_QUOTES.length;
      this.setData({ loadingQuote: LOADING_QUOTES[index] });
    }, 2000);
  },

  // 分批加载名字
  fetchNamesBatch(keyword, mode, surname) {
    // 第一波：请求2个名字，快速展示
    this.fetchFirstBatch(keyword, mode, surname, 2);
  },

  // 第一波：快速获取前2个名字
  fetchFirstBatch(keyword, mode, surname, count) {
    const apiBaseUrl = getApp().globalData.apiBaseUrl;
    const requestData = { 
      keyword, 
      count: count,
      batch: 'first'
    };
    if (mode) requestData.mode = mode;
    if (surname) requestData.surname = surname;
    
    wx.request({
      url: `${apiBaseUrl}/api/names/generate`,
      data: requestData,
      success: (res) => {
        if (res.statusCode === 200 && res.data && res.data.length > 0) {
          // 清除定时器
          if (this.loadingQuoteTimer) {
            clearInterval(this.loadingQuoteTimer);
            this.loadingQuoteTimer = null;
          }
          
          // 立即展示第一波结果
          this.setData({ 
            nameList: res.data, 
            currentIndex: 0, 
            isLoading: false, 
            cardKey: this.data.cardKey + 1 
          });
          
          // 静默加载剩余3个名字
          this.fetchSecondBatch(keyword, mode, surname, 3);
        } else {
          this.handleFetchError('意境未达，请重试');
        }
      },
      fail: () => {
        this.handleFetchError('网络疏离，请检查后端');
      }
    });
  },

  // 第二波：静默加载剩余名字
  fetchSecondBatch(keyword, mode, surname, count) {
    const apiBaseUrl = getApp().globalData.apiBaseUrl;
    const requestData = { 
      keyword, 
      count: count,
      batch: 'second'
    };
    if (mode) requestData.mode = mode;
    if (surname) requestData.surname = surname;
    
    wx.request({
      url: `${apiBaseUrl}/api/names/generate`,
      data: requestData,
      success: (res) => {
        if (res.statusCode === 200 && res.data && res.data.length > 0) {
          // 平滑合并数据
          const currentList = this.data.nameList;
          const newList = [...currentList, ...res.data];
          this.setData({ nameList: newList });
          console.log('第二波数据已静默加载，当前共', newList.length, '个名字');
        }
      },
      fail: (err) => {
        console.log('第二波加载失败（不影响已展示内容）:', err);
      }
    });
  },

  // 处理加载错误
  handleFetchError(message) {
    if (this.loadingQuoteTimer) {
      clearInterval(this.loadingQuoteTimer);
      this.loadingQuoteTimer = null;
    }
    this.setData({ isLoading: false });
    wx.showToast({ title: message, icon: 'none' });
  },

  // 返回首页
  onBack() {
    wx.navigateBack({
      success: () => {
        // 返回成功后，首页的 onShow 会重置状态
      }
    });
  },

  // 点击不喜欢按钮
  onDislike() {
    if (this.isExiting) return;
    this.isExiting = true;
    
    getApp().playAudio('swipe');
    this.setData({
      translateX: -500,
      opacity: 0,
      transition: 'all 0.3s cubic-bezier(0.6, -0.28, 0.735, 0.045)'
    });
  },

  // 点击喜欢按钮
  onLike() {
    if (this.isExiting) return;
    this.handleLike();
    
    this.isExiting = true;
    this.setData({
      translateX: 500,
      opacity: 0,
      transition: 'all 0.3s cubic-bezier(0.6, -0.28, 0.735, 0.045)'
    });
  },

  onFlip() {
    // 守卫：如果这是一次拖拽，isDragging 会为 true，则不执行翻转
    if (this.isDragging || this.isExiting) return;
    
    getApp().playAudio('flip');
    this.setData({ isFlipped: !this.data.isFlipped });
  },

  onTouchStart(e) {
    if (this.isExiting) return;
    
    this.isDragging = false; // 每次开始触摸时，都假定为点击，而非拖拽
    this.startX = e.touches[0].clientX;
    this.lastX = this.startX;
    this.startY = e.touches[0].clientY;
    this.startTime = Date.now();
    this.setData({ transition: 'none' }); 
  },

  onTouchMove(e) {
    if (this.isExiting) return;

    const deltaX = e.touches[0].clientX - this.startX;
    // 只有移动超过5px，才真正判定为"拖拽"
    if (Math.abs(deltaX) > 5) {
        this.isDragging = true;
    }

    // 如果不是拖拽，则不进行任何移动
    if (!this.isDragging) return;

    this.lastX = e.touches[0].clientX;
    const rotate = deltaX * 0.05;
    const opacity = 1 - Math.abs(deltaX) / 200;
    this.setData({
      translateX: deltaX,
      rotate: rotate,
      opacity: opacity
    });
  },

  onTouchEnd() {
    if (this.isExiting) return;

    // 如果不是拖拽（即这是一次纯点击），则 onTouchEnd 不执行任何操作，交由 onFlip 处理
    if (!this.isDragging) {
      return;
    }
    
    // 以下是拖拽结束后的逻辑
    const deltaX = this.lastX - this.startX;
    const deltaTime = Date.now() - this.startTime;
    const velocity = deltaX / deltaTime;
    const shouldExit = Math.abs(deltaX) > EXIT_THRESHOLD || Math.abs(velocity) > FAST_SWIPE_VELOCITY;

    if (shouldExit) {
      this.isExiting = true;
      const direction = deltaX > 0 ? 1 : -1;
      const targetX = direction * 500;
      
      // 播放滑动音效
      getApp().playAudio('swipe');
      // 触觉反馈
      wx.vibrateShort({ type: 'light' });
      
      this.setData({
        translateX: targetX,
        opacity: 0,
        transition: 'all 0.3s cubic-bezier(0.6, -0.28, 0.735, 0.045)'
      });
    } else {
      this.setData({
        translateX: 0,
        rotate: 0,
        opacity: 1,
        transition: 'all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275)'
      });
    }
    
    // 延迟重置 isDragging 标志位。
    // 这是为了确保在系统触发 tap 事件时，isDragging 标志仍然为 true，
    // 从而让 onFlip 方法可以正确地忽略掉这次由拖拽产生的 tap。
    setTimeout(() => {
      this.isDragging = false;
    }, 100);
  },

  onTransitionEnd() {
    if (!this.isExiting) return;

    const direction = this.data.translateX > 0 ? 'like' : 'dislike';
    if (direction === 'like') {
      this.handleLike();
    }
    this.handleCardExit(direction);
  },

  handleLike() {
    // 触觉反馈 - 中等震动
    wx.vibrateShort({ type: 'medium' });
    // 音效反馈
    getApp().playAudio('success');
    
    const card = this.data.nameList[this.data.currentIndex];
    if (!this.data.collectedNames.some(item => item.name === card.name)) {
      this.setData({ collectedNames: [...this.data.collectedNames, card] });
      
      // 同步到后端
      this.syncFavoriteToBackend(card);
    }
  },

  // 同步收藏到后端
  syncFavoriteToBackend(card) {
    const openid = 'test_openid'; // 实际应从登录获取
    const apiBaseUrl = getApp().globalData.apiBaseUrl;
    wx.request({
      url: `${apiBaseUrl}/api/favorites/add?openid=${openid}&mode=${this.data.mode}&keyword=${encodeURIComponent(this.data.keyword)}`,
      method: 'POST',
      header: {
        'Content-Type': 'application/json'
      },
      data: {
        name: card.name,
        origin: card.origin,
        description: card.description,
        tone: card.tone,
        score: card.score
      },
      success: (res) => {
        if (res.data && res.data.success) {
          console.log('收藏同步成功');
        } else {
          console.log('收藏同步失败:', res.data);
        }
      },
      fail: (err) => {
        console.log('收藏同步失败:', err);
      }
    });
  },

  handleCardExit() {
    const nextIndex = this.data.currentIndex + 1;
    wx.nextTick(() => {
      this.setData({
        transition: 'none',
        translateX: 0,
        rotate: 0,
        opacity: 1,
        isFlipped: false
      }, () => {
        if (nextIndex < this.data.nameList.length) {
          this.setData({ currentIndex: nextIndex, cardKey: this.data.cardKey + 1 });
        } else {
          wx.showModal({
            title: '见素时刻',
            content: '这一波灵感已尽，是否再求几名？',
            confirmText: '再求', cancelText: '返回',
            success: (res) => { 
              if (res.confirm) {
                this.setData({ isLoading: true });
                this.startLoadingQuoteRotation();
                this.fetchNamesBatch(this.data.keyword, this.data.mode, this.data.surname);
              } else {
                this.onBack();
              }
            }
          });
        }
        this.isExiting = false;
      });
    });
  },

  toggleCollectionView() {
    // 跳转到 profile 页面
    wx.navigateTo({
      url: '/pages/profile/profile'
    });
  },

  onDeleteCollected(e) {
    const nameToDelete = e.currentTarget.dataset.name;
    this.setData({
      collectedNames: this.data.collectedNames.filter(item => item.name !== nameToDelete)
    });
    wx.vibrateShort({ type: 'light' });
  },
  
  // 显示海报弹窗
  onSavePoster() {
    const card = this.data.nameList[this.data.currentIndex];
    const nameChars = card.name.split('');
    
    this.setData({
      showPoster: true,
      posterNameChars: nameChars
    });
    
    // 触觉反馈
    wx.vibrateShort({ type: 'light' });
  },

  // 关闭海报弹窗
  closePoster() {
    this.setData({ showPoster: false });
  },

  // 保存海报到相册
  savePoster() {
    wx.showLoading({ title: '绘笔收录中...', mask: true });
    
    // 使用 snapshot 组件截图
    wx.nextTick(() => {
      const query = wx.createSelectorQuery().in(this);
      query.select('#posterArea')
        .node()
        .exec((res) => {
          const node = res[0].node;
          
          // 使用 snapshot 截图
          wx.canvasToTempFilePath({
            x: 0,
            y: 0,
            width: node.width,
            height: node.height,
            destWidth: node.width * 2,
            destHeight: node.height * 2,
            canvasId: 'posterCanvas',
            success: (res) => {
              wx.hideLoading();
              wx.saveImageToPhotosAlbum({
                filePath: res.tempFilePath,
                success: () => {
                  wx.showToast({ title: '已保存到相册', icon: 'success' });
                },
                fail: () => {
                  wx.showToast({ title: '保存失败', icon: 'none' });
                }
              });
            },
            fail: () => {
              wx.hideLoading();
              wx.showToast({ title: '绘笔受阻', icon: 'none' });
            }
          });
        });
    });
  },

  // 分享海报
  sharePoster() {
    wx.showShareImageMenu({
      path: '/images/share.png'
    });
  },

  // 阻止事件冒泡
  preventBubble() {
    // 什么都不做，只是阻止事件冒泡
  }
});