Page({
  data: {
    // 专家信息
    expertInfo: {
      id: 1,
      name: '张明专家',
      title: '资深畜牧兽医',
      expertise: '牛羊疾病防治',
      avatar: '/images/avatars/expert1.png',
      online: true,
      phone: '13800138000'
    },
    
    // 用户信息
    userInfo: {
      id: 1001,
      name: '养殖户',
      avatar: '/images/avatars/user.png'
    },
    
    // 消息列表
    messageList: [],
    scrollTop: 0,
    scrollAnimate: false,
    
    // 输入相关 - 优化
    inputValue: '',
    inputFocus: false,
    
    // 多媒体
    showMediaSheet: false,
    
    // 页面状态
    showDateDivider: true,
    todayDate: '',
    loading: false,
    loadingMore: false,
    
    // 滚动相关
    isScrolling: false,
    lastScrollTop: 0,
    
    // 当前专家ID
    currentExpertId: 1,
    
    // 分页相关
    page: 1,
    pageSize: 20,
    hasMore: true,
    
    // 时间显示间隔
    timeInterval: 5,
    lastShowTimeStamp: 0,
    
    // 键盘高度
    keyboardHeight: 0
  },

  onLoad: function(options) {
    this.setTodayDate();
    this.loadUserInfo();
    
    if (options.expertId) {
      this.setData({ currentExpertId: options.expertId });
      this.loadExpertInfo(options.expertId);
    } else {
      this.loadChatHistory();
    }
    
    wx.onKeyboardHeightChange(this.onKeyboardHeightChange.bind(this));
  },

  onUnload: function() {
    wx.offKeyboardHeightChange();
  },

  // ========== 输入框相关方法 ==========
  
  // 输入处理
  onInput: function(e) {
    this.setData({
      inputValue: e.detail.value
    });
  },

  // 输入框获得焦点
  onInputFocus: function() {
    this.setData({
      inputFocus: true
    }, () => {
      setTimeout(() => {
        this.scrollToBottom();
      }, 200);
    });
  },

  // 输入框失去焦点
  onInputBlur: function() {
    this.setData({
      inputFocus: false
    });
  },

  // 清除输入
  clearInput: function() {
    this.setData({
      inputValue: '',
      inputFocus: true
    });
  },

  // 发送文本消息
  sendTextMessage: function() {
    const content = this.data.inputValue.trim();
    if (!content) return;
    
    const newMessage = {
      id: 'msg-' + Date.now(),
      sender: 'user',
      type: 'text',
      content: content,
      timestamp: Date.now(),
      status: 'sending'
    };
    
    this.addMessageToList(newMessage);
    
    // 清空输入框
    this.setData({
      inputValue: '',
      inputFocus: false
    });
    
    // 模拟发送成功
    setTimeout(() => {
      this.updateMessageStatus(newMessage.id, 'success');
      
      setTimeout(() => {
        this.receiveExpertReply();
      }, 1000);
    }, 500);
  },

  // 添加消息到列表
  addMessageToList: function(message) {
    const { messageList } = this.data;
    const processedMessage = this.processSingleMessageTime(message, messageList);
    
    messageList.push(processedMessage);
    
    this.setData({ messageList }, () => {
      this.scrollToBottom();
    });
  },

  // 更新消息状态
  updateMessageStatus: function(messageId, status) {
    const { messageList } = this.data;
    const index = messageList.findIndex(msg => msg.id === messageId);
    
    if (index !== -1) {
      messageList[index].status = status;
      this.setData({ messageList });
    }
  },

  // 接收专家回复
  receiveExpertReply: function() {
    const replies = [
      '收到您的消息，让我分析一下您说的情况。',
      '建议您提供更多细节，比如发病时间、具体症状等。',
      '根据描述，可能是饲料问题引起的，建议调整饲料配方。',
      '可以考虑添加一些维生素补充剂，改善食欲问题。',
      '最好能提供照片，这样我可以更准确地判断情况。'
    ];
    
    const randomReply = replies[Math.floor(Math.random() * replies.length)];
    
    const newMessage = {
      id: 'exp-' + Date.now(),
      sender: 'expert',
      type: 'text',
      content: randomReply,
      timestamp: Date.now(),
      status: 'success'
    };
    
    this.addMessageToList(newMessage);
  },

  // ========== 滚动相关 ==========
  
  // 滚动事件
  onScroll: function(e) {
    const scrollTop = e.detail.scrollTop;
    this.setData({
      lastScrollTop: scrollTop,
      isScrolling: true
    });
    
    clearTimeout(this.scrollTimer);
    this.scrollTimer = setTimeout(() => {
      this.setData({ isScrolling: false });
    }, 200);
    
    if (scrollTop <= 100 && !this.data.loadingMore && this.data.hasMore) {
      this.loadMoreMessages();
    }
  },

  // 加载更多消息
  loadMoreMessages: function() {
    if (this.data.loadingMore || !this.data.hasMore) return;
    
    this.setData({ 
      loadingMore: true,
      page: this.data.page + 1
    }, () => {
      this.loadChatHistory();
    });
  },

  // 滚动到底部
  scrollToBottom: function(animate = true) {
    if (this.data.isScrolling) return;
    
    this.setData({
      scrollAnimate: animate
    }, () => {
      setTimeout(() => {
        this.setData({
          scrollTop: 999999
        });
      }, 50);
    });
  },

  // 键盘高度变化
  onKeyboardHeightChange: function(res) {
    this.setData({
      keyboardHeight: res.height
    });
    
    if (res.height > 0) {
      this.setData({ showMediaSheet: false });
      
      setTimeout(() => {
        this.scrollToBottom();
      }, 100);
    }
  },

  // ========== 多媒体相关 ==========
  
  // 显示多媒体选择面板
  showMediaActionSheet: function() {
    this.setData({
      showMediaSheet: true,
      inputFocus: false
    });
  },

  // 隐藏多媒体选择面板
  hideMediaActionSheet: function() {
    this.setData({
      showMediaSheet: false
    });
  },

  // 选择图片
  chooseImage: function() {
    this.hideMediaActionSheet();
    
    wx.chooseImage({
      count: 9,
      sizeType: ['compressed'],
      sourceType: ['album'],
      success: (res) => {
        this.uploadImages(res.tempFilePaths);
      },
      fail: (err) => {
        wx.showToast({
          title: '选择图片失败',
          icon: 'none'
        });
      }
    });
  },

  // 选择视频
  chooseVideo: function() {
    this.hideMediaActionSheet();
    
    wx.chooseVideo({
      sourceType: ['album'],
      compressed: true,
      maxDuration: 60,
      success: (res) => {
        this.uploadVideo(res.tempFilePath, res.thumbTempFilePath);
      },
      fail: (err) => {
        wx.showToast({
          title: '选择视频失败',
          icon: 'none'
        });
      }
    });
  },

  // 选择文件
  chooseFile: function() {
    this.hideMediaActionSheet();
    
    wx.chooseMessageFile({
      count: 1,
      type: 'all',
      success: (res) => {
        const file = res.tempFiles[0];
        this.uploadFile(file.path, file.name, file.size);
      },
      fail: (err) => {
        wx.showToast({
          title: '选择文件失败',
          icon: 'none'
        });
      }
    });
  },

  // 上传图片
  uploadImages: function(tempFilePaths) {
    tempFilePaths.forEach((tempFilePath, index) => {
      const fileName = `image_${Date.now()}_${index}.jpg`;
      this.uploadFile(tempFilePath, fileName, 0, 'image');
    });
  },

  // 上传视频
  uploadVideo: function(tempFilePath, thumbPath) {
    const fileName = `video_${Date.now()}.mp4`;
    this.uploadFile(tempFilePath, fileName, 0, 'video', thumbPath);
  },

  // 通用文件上传
  uploadFile: function(tempFilePath, fileName, fileSize = 0, type = 'file', thumbPath = '') {
    const messageId = 'file-' + Date.now();
    const message = {
      id: messageId,
      sender: 'user',
      type: type,
      content: tempFilePath,
      thumb: thumbPath,
      fileName: fileName,
      fileSize: fileSize,
      extension: fileName.split('.').pop().toLowerCase(),
      timestamp: Date.now(),
      status: 'uploading',
      progress: 0
    };
    
    this.addMessageToList(message);
    this.simulateUpload(messageId, type);
  },

  // 模拟上传过程
  simulateUpload: function(messageId, type) {
    let progress = 0;
    const uploadInterval = setInterval(() => {
      progress += Math.random() * 20 + 10;
      
      if (progress >= 100) {
        progress = 100;
        clearInterval(uploadInterval);
        
        setTimeout(() => {
          this.updateMessageStatus(messageId, 'success');
          
          const { messageList } = this.data;
          const index = messageList.findIndex(msg => msg.id === messageId);
          if (index !== -1) {
            delete messageList[index].progress;
            this.setData({ messageList });
            
            if (type === 'image' || type === 'video') {
              setTimeout(() => {
                this.receiveMediaReply(type);
              }, 800);
            }
          }
        }, 200);
      }
      
      const { messageList } = this.data;
      const index = messageList.findIndex(msg => msg.id === messageId);
      if (index !== -1) {
        messageList[index].progress = Math.min(progress, 100);
        this.setData({ messageList });
      }
    }, 100);
  },

  // 接收媒体回复
  receiveMediaReply: function(type) {
    const imageReplies = [
      '照片收到了，牛的状况看起来确实不太理想。',
      '从照片看，饲养环境需要改善一下。',
      '图片清晰，我可以更准确地判断问题了。'
    ];
    
    const videoReplies = [
      '视频看到了，动物的精神状态需要关注。',
      '从视频可以观察到更多细节，这很有帮助。',
      '视频内容很有价值，让我了解了具体情况。'
    ];
    
    const replies = type === 'image' ? imageReplies : videoReplies;
    const randomReply = replies[Math.floor(Math.random() * replies.length)];
    
    const newMessage = {
      id: 'exp-media-' + Date.now(),
      sender: 'expert',
      type: 'text',
      content: randomReply,
      timestamp: Date.now(),
      status: 'success'
    };
    
    this.addMessageToList(newMessage);
  },

  // 预览图片
  previewImage: function(e) {
    const url = e.currentTarget.dataset.url;
    wx.previewImage({
      current: url,
      urls: [url]
    });
  },

  // ========== 数据初始化 ==========
  
  // 设置今天日期
  setTodayDate: function() {
    const now = new Date();
    const month = now.getMonth() + 1;
    const date = now.getDate();
    const week = ['日', '一', '二', '三', '四', '五', '六'][now.getDay()];
    this.setData({
      todayDate: `${month}月${date}日 星期${week}`
    });
  },

  // 加载用户信息
  loadUserInfo: function() {
    try {
      const userInfo = wx.getStorageSync('userInfo');
      if (userInfo) {
        this.setData({ userInfo });
      }
    } catch (e) {
      console.error('加载用户信息失败:', e);
    }
  },

  // 加载专家信息
  loadExpertInfo: function(expertId) {
    wx.showLoading({ title: '加载中...' });
    
    // 模拟网络请求
    setTimeout(() => {
      this.setData({
        expertInfo: {
          id: Number(expertId),
          name: '张明专家',
          title: '资深畜牧兽医',
          expertise: '牛羊疾病防治',
          avatar: '/images/avatars/expert1.png',
          online: true,
          phone: '13800138000'
        },
        loading: false
      });
      
      wx.hideLoading();
      this.loadChatHistory();
    }, 500);
  },

  // 加载聊天记录
  loadChatHistory: function() {
    this.setData({ loading: true });
    
    // 模拟历史消息
    setTimeout(() => {
      const now = Date.now();
      const mockMessages = [
        {
          id: 'msg-1',
          sender: 'expert',
          type: 'text',
          content: '您好，我是张明专家，有什么可以帮您？',
          timestamp: now - 10 * 60 * 1000,
          status: 'success'
        },
        {
          id: 'msg-2',
          sender: 'user',
          type: 'text',
          content: '您好，我养的牛最近食欲不振，请问是什么原因？',
          timestamp: now - 9 * 60 * 1000,
          status: 'success'
        },
        {
          id: 'msg-3',
          sender: 'expert',
          type: 'text',
          content: '可能是饲料问题或环境变化引起的，请描述一下具体情况。',
          timestamp: now - 7 * 60 * 1000,
          status: 'success'
        },
        {
          id: 'msg-4',
          sender: 'user',
          type: 'text',
          content: '具体症状是拉稀，体温偏高，精神状态不好。',
          timestamp: now - 2 * 60 * 1000,
          status: 'success'
        },
        {
          id: 'msg-5',
          sender: 'expert',
          type: 'text',
          content: '明白了，建议您调整饲料配方，添加一些益生菌。',
          timestamp: now - 1 * 60 * 1000,
          status: 'success'
        }
      ];
      
      const processedMessages = this.processMessageTimes(mockMessages);
      
      this.setData({
        messageList: processedMessages,
        loading: false,
        hasMore: false
      }, () => {
        this.scrollToBottom(true);
      });
    }, 800);
  },

  // 处理消息时间显示
  processMessageTimes: function(messages) {
    if (!messages || messages.length === 0) return [];
    
    const sortedMessages = [...messages].sort((a, b) => a.timestamp - b.timestamp);
    const processedMessages = [];
    let lastShowTime = null;
    
    for (let i = 0; i < sortedMessages.length; i++) {
      const msg = { ...sortedMessages[i] };
      
      if (!msg.timestamp || isNaN(msg.timestamp) || msg.timestamp <= 0) {
        msg.timestamp = Date.now() - (sortedMessages.length - i) * 60000;
      }
      
      if (i === 0) {
        msg.showTime = true;
        lastShowTime = msg.timestamp;
      } else {
        const timeDiffMinutes = (msg.timestamp - lastShowTime) / (1000 * 60);
        msg.showTime = timeDiffMinutes >= this.data.timeInterval;
        if (msg.showTime) lastShowTime = msg.timestamp;
      }
      
      processedMessages.push(msg);
    }
    
    if (lastShowTime) {
      this.setData({ lastShowTimeStamp: lastShowTime });
    }
    
    return processedMessages;
  },

  // 处理单条消息时间
  processSingleMessageTime: function(message, messageList) {
    const msg = { ...message };
    
    if (!msg.timestamp || isNaN(msg.timestamp) || msg.timestamp <= 0) {
      msg.timestamp = Date.now();
    }
    
    if (messageList.length === 0) {
      msg.showTime = true;
      this.setData({ lastShowTimeStamp: msg.timestamp });
      return msg;
    }
    
    const lastShowTime = this.data.lastShowTimeStamp;
    const timeDiffMinutes = (msg.timestamp - lastShowTime) / (1000 * 60);
    
    msg.showTime = timeDiffMinutes >= this.data.timeInterval;
    if (msg.showTime) {
      this.setData({ lastShowTimeStamp: msg.timestamp });
    }
    
    return msg;
  },

  // ========== 工具方法 ==========
  
  // 格式化时间
  formatTime: function(timestamp) {
    if (!timestamp || timestamp <= 0) return '未知时间';
    
    const date = new Date(Number(timestamp));
    if (isNaN(date.getTime())) return '未知时间';
    
    const hours = date.getHours().toString().padStart(2, '0');
    const minutes = date.getMinutes().toString().padStart(2, '0');
    return `${hours}:${minutes}`;
  },

  // 格式化文件大小
  formatFileSize: function(bytes) {
    if (!bytes || bytes === 0) return '0B';
    
    const units = ['B', 'KB', 'MB', 'GB'];
    let size = bytes;
    let unitIndex = 0;
    
    while (size >= 1024 && unitIndex < units.length - 1) {
      size /= 1024;
      unitIndex++;
    }
    
    return size.toFixed(1) + units[unitIndex];
  },

  // 阻止事件冒泡
  stopPropagation: function() {}
});