const { request, uploadFile, streamRequest } = require('../../utils/request')
const { splitMarkdownImages } = require('../../utils/parse-image')

const app = getApp()

// 语音识别插件（微信同声传译 WechatSI）
let speechPlugin = null
try {
  speechPlugin = requirePlugin('WechatSI')
} catch (e) {
  speechPlugin = null
}

Page({
  data: {
    userName: '',
    messages: [],           // [{ key, role, text, attachments?, references?, streaming? }]
    question: '',
    pendingImages: [],      // [{ id, file_type, data_url }]
    conversationId: null,
    streaming: false,
    scrollAnchor: '',
    voiceMode: false,
    recording: false,
    drawerOpen: false,
    sessions: [],
    sessionsLoading: false,
    avatarChar: '?',
    userSub: ''
  },

  _msgSeq: 0,
  _recorderManager: null,
  _recognizeManager: null,
  _recognizedText: '',
  _currentTask: null,

  onLoad(options) {
    const token = app.globalData.token || wx.getStorageSync('token')
    if (!token) {
      wx.redirectTo({ url: '/pages/login/login' })
      return
    }
    const user = app.globalData.user || wx.getStorageSync('user') || {}
    const userName = user.name || user.phone || ''
    const userSub = user.name && user.phone ? user.phone : ''
    const avatarChar = (userName || '?').trim().charAt(0).toUpperCase() || '?'
    this.setData({ userName, userSub, avatarChar })

    this._recorderManager = wx.getRecorderManager()
    this._setupSpeech()

    // 消费 home 页跳转带来的 pending 意图
    const pending = app.globalData.chatPending || {}
    app.globalData.chatPending = null
    const sid = (options && options.sid) || pending.sid
    if (sid) {
      this._loadSessionMessages(Number(sid))
    } else if (pending.question) {
      this.setData({ question: pending.question })
      setTimeout(() => this.submit(), 0)
    } else if (pending.attach) {
      setTimeout(() => this.chooseImage(), 0)
    } else if (pending.voice) {
      this.setData({ voiceMode: true })
    }
  },

  onUnload() {
    if (this._currentTask && this._currentTask.abort) {
      try { this._currentTask.abort() } catch (e) {}
    }
  },

  _nextKey() {
    this._msgSeq += 1
    return 'k' + this._msgSeq
  },

  _appendMessage(msg) {
    const list = this.data.messages.slice()
    const key = this._nextKey()
    list.push(Object.assign({ key }, msg))
    this.setData({ messages: list, scrollAnchor: 'anchor-end' })
    return key
  },

  _updateAssistant(key, patch) {
    const list = this.data.messages.slice()
    const i = list.findIndex((m) => m.key === key)
    if (i === -1) return
    const merged = Object.assign({}, list[i], patch)
    if (patch && typeof patch.text === 'string') {
      merged.contentSegments = splitMarkdownImages(merged.text)
    }
    list[i] = merged
    this.setData({ messages: list, scrollAnchor: 'anchor-end' })
  },

  _appendAssistantDelta(key, delta) {
    const list = this.data.messages.slice()
    const i = list.findIndex((m) => m.key === key)
    if (i === -1) return
    const newText = (list[i].text || '') + delta
    list[i] = Object.assign({}, list[i], {
      text: newText,
      contentSegments: splitMarkdownImages(newText)
    })
    this.setData({ messages: list, scrollAnchor: 'anchor-end' })
  },

  onQuestionInput(e) {
    this.setData({ question: e.detail.value })
  },

  goBack() {
    const pages = getCurrentPages()
    if (pages && pages.length > 1) {
      wx.navigateBack()
    } else {
      wx.redirectTo({ url: '/pages/home/home' })
    }
  },

  // ---------------- 抽屉 ----------------
  openDrawer() {
    this.setData({ drawerOpen: true })
    this._loadSessions()
  },

  closeDrawer() {
    this.setData({ drawerOpen: false })
  },

  async _loadSessions() {
    this.setData({ sessionsLoading: true })
    try {
      const list = await request('/api/chat/sessions')
      const items = (list || []).map((s) => Object.assign({}, s, { _time: this._formatTime(s.last_message_at || s.created_at) }))
      this.setData({ sessions: items })
    } catch (e) {
      wx.showToast({ title: '历史加载失败：' + e.message, icon: 'none' })
    } finally {
      this.setData({ sessionsLoading: false })
    }
  },

  _formatTime(iso) {
    if (!iso) return ''
    const d = new Date(iso)
    if (isNaN(d.getTime())) return ''
    const pad = (n) => (n < 10 ? '0' + n : '' + n)
    const now = new Date()
    if (d.getFullYear() === now.getFullYear() && d.getMonth() === now.getMonth() && d.getDate() === now.getDate()) {
      return `${pad(d.getHours())}:${pad(d.getMinutes())}`
    }
    return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}`
  },

  newConversation() {
    if (this.data.streaming) {
      wx.showToast({ title: '当前对话生成中', icon: 'none' })
      return
    }
    this.setData({ drawerOpen: false })
    wx.redirectTo({ url: '/pages/home/home' })
  },

  onSelectSession(e) {
    if (this.data.streaming) {
      wx.showToast({ title: '当前对话生成中', icon: 'none' })
      return
    }
    const id = e.detail && e.detail.id
    if (!id || id === this.data.conversationId) {
      this.setData({ drawerOpen: false })
      return
    }
    this.setData({ drawerOpen: false })
    this._loadSessionMessages(Number(id))
  },

  async _loadSessionMessages(id) {
    wx.showLoading({ title: '加载中...', mask: true })
    try {
      const list = await request(`/api/chat/sessions/${id}/messages`)
      const msgs = []
      ;(list || []).forEach((m) => {
        if (m.question) {
          this._msgSeq += 1
          msgs.push({
            key: 'k' + this._msgSeq,
            role: 'user',
            text: m.question,
            attachments: m.attachments || []
          })
        }
        if (m.answer || (m.references && m.references.length)) {
          this._msgSeq += 1
          const ansText = m.answer || ''
          msgs.push({
            key: 'k' + this._msgSeq,
            role: 'assistant',
            text: ansText,
            contentSegments: splitMarkdownImages(ansText),
            references: m.references || [],
            streaming: false
          })
        }
      })
      this.setData({
        messages: msgs,
        conversationId: id,
        scrollAnchor: 'anchor-end'
      })
    } catch (err) {
      wx.showToast({ title: '加载失败：' + err.message, icon: 'none' })
    } finally {
      wx.hideLoading()
    }
  },

  // ---------------- 图片 ----------------
  chooseImage() {
    if (this.data.streaming) return
    wx.chooseMedia({
      count: 4 - this.data.pendingImages.length,
      mediaType: ['image'],
      sourceType: ['album', 'camera'],
      sizeType: ['compressed'],
      success: (res) => {
        res.tempFiles.forEach((tf) => this._uploadTempImage(tf))
      }
    })
  },

  async _uploadTempImage(tempFile) {
    wx.showLoading({ title: '上传中...', mask: true })
    try {
      const result = await uploadFile('/api/chat/upload-image', tempFile.tempFilePath, 'file')
      // 使用本地路径作为预览
      const list = this.data.pendingImages.slice()
      list.push({
        id: result.id,
        file_type: 'image/jpeg',
        data_url: tempFile.tempFilePath
      })
      this.setData({ pendingImages: list })
    } catch (e) {
      wx.showToast({ title: '上传失败：' + e.message, icon: 'none' })
    } finally {
      wx.hideLoading()
    }
  },

  removePending(e) {
    const idx = e.currentTarget.dataset.index
    const list = this.data.pendingImages.slice()
    list.splice(idx, 1)
    this.setData({ pendingImages: list })
  },

  previewImage(e) {
    const src = e.currentTarget.dataset.src
    if (src) {
      wx.previewImage({ current: src, urls: [src] })
    }
  },

  // 点击参考来源标题, 折叠/展开链接和摘要
  toggleRef(e) {
    const mkey = e.currentTarget.dataset.mkey
    const idx = Number(e.currentTarget.dataset.idx)
    const list = this.data.messages.slice()
    const i = list.findIndex((m) => m.key === mkey)
    if (i === -1) return
    const refs = (list[i].references || []).slice()
    if (!refs[idx]) return
    refs[idx] = Object.assign({}, refs[idx], { expanded: !refs[idx].expanded })
    list[i] = Object.assign({}, list[i], { references: refs })
    this.setData({ messages: list })
  },

  // 参考文档带 source_url 时(共享文档)点击复制链接到剪贴板。
  // 小程序无法直接打开任意外链, 复制后由用户粘贴到浏览器。
  onRefLinkTap(e) {
    const url = e.currentTarget.dataset.url
    if (!url) return
    wx.setClipboardData({
      data: url,
      success: () => wx.showToast({ title: '链接已复制', icon: 'success' }),
      fail: () => wx.showToast({ title: '复制失败', icon: 'none' })
    })
  },

  // 长按聊天记录里的图片 (自己发的 or AI 回答里的 markdown 图片) -> 弹菜单
  onImageLongPress(e) {
    const src = e.currentTarget.dataset.src
    if (!src) return
    wx.showActionSheet({
      itemList: ['预览大图', '引用此图追问', '保存到相册'],
      success: (r) => {
        if (r.tapIndex === 0) wx.previewImage({ current: src, urls: [src] })
        else if (r.tapIndex === 1) this._quoteImage(src)
        else if (r.tapIndex === 2) this._saveImageToAlbum(src)
      }
    })
  },

  async _quoteImage(src) {
    if (this.data.streaming) {
      wx.showToast({ title: '当前对话生成中', icon: 'none' })
      return
    }
    if (this.data.pendingImages.length >= 4) {
      wx.showToast({ title: '最多 4 张图', icon: 'none' })
      return
    }
    const localPath = await this._materializeToLocal(src)
    if (!localPath) return
    await this._uploadTempImage({ tempFilePath: localPath })
  },

  async _saveImageToAlbum(src) {
    const path = await this._materializeToLocal(src)
    if (!path) return
    wx.saveImageToPhotosAlbum({
      filePath: path,
      success: () => wx.showToast({ title: '已保存到相册' }),
      fail: (err) => wx.showToast({ title: '保存失败：' + (err.errMsg || ''), icon: 'none' })
    })
  },

  // 把任意来源 (远端 URL / data URL / 本地临时路径) 归一化成本地文件路径,
  // 后续能直接喂给 wx.uploadFile / wx.saveImageToPhotosAlbum。失败时返回 null 并已给用户提示。
  _materializeToLocal(src) {
    if (!src) return Promise.resolve(null)
    if (src.indexOf('data:') === 0) return this._dataUrlToTempFile(src)
    if (/^https?:\/\//.test(src)) return this._downloadRemote(src)
    return Promise.resolve(src)
  },

  _dataUrlToTempFile(dataUrl) {
    return new Promise((resolve) => {
      const m = /^data:([^;]+);base64,(.+)$/.exec(dataUrl)
      if (!m) {
        wx.showToast({ title: '图片格式无法识别', icon: 'none' })
        resolve(null)
        return
      }
      const ext = (m[1].split('/')[1] || 'png').replace(/[^a-z0-9]/gi, '') || 'png'
      const path = `${wx.env.USER_DATA_PATH}/quote_${Date.now()}.${ext}`
      wx.getFileSystemManager().writeFile({
        filePath: path,
        data: m[2],
        encoding: 'base64',
        success: () => resolve(path),
        fail: (err) => {
          wx.showToast({ title: '写临时文件失败: ' + (err.errMsg || ''), icon: 'none' })
          resolve(null)
        }
      })
    })
  },

  _downloadRemote(url) {
    wx.showLoading({ title: '拉取图片...', mask: true })
    return new Promise((resolve) => {
      wx.downloadFile({
        url,
        success: (r) => {
          wx.hideLoading()
          if (r.statusCode === 200) {
            resolve(r.tempFilePath)
          } else {
            wx.showToast({ title: '下载失败 HTTP ' + r.statusCode, icon: 'none' })
            resolve(null)
          }
        },
        fail: (err) => {
          wx.hideLoading()
          wx.showModal({
            title: '拉图失败',
            content: (err.errMsg || '') + '\n\n若提示"域名不在合法列表"，请在微信公众平台 -> 开发 -> 服务器域名 里把该图片来源域名加进 downloadFile 合法域名。',
            showCancel: false
          })
          resolve(null)
        }
      })
    })
  },

  // ---------------- 语音 ----------------
  toggleVoiceMode() {
    this.setData({ voiceMode: !this.data.voiceMode })
  },

  _setupSpeech() {
    if (!speechPlugin) return
    // 复用插件的 recognizer 通道；直接使用 speechPlugin.getRecordRecognitionManager
    this._recognizeManager = speechPlugin.getRecordRecognitionManager()
    this._recognizeManager.onStart = () => {
      this.setData({ recording: true })
    }
    this._recognizeManager.onRecognize = (res) => {
      this._recognizedText = res.result || ''
    }
    this._recognizeManager.onStop = (res) => {
      this.setData({ recording: false })
      const text = (res && res.result) || this._recognizedText || ''
      this._recognizedText = ''
      if (text) {
        // 识别到文本，直接作为问题发送
        this.setData({ question: text })
        this.submit()
      } else {
        wx.showToast({ title: '未识别到语音', icon: 'none' })
      }
    }
    this._recognizeManager.onError = (err) => {
      this.setData({ recording: false })
      wx.showToast({ title: '语音识别失败：' + (err.msg || err.errMsg || ''), icon: 'none' })
    }
  },

  startRecord() {
    if (this.data.streaming) return
    if (!speechPlugin || !this._recognizeManager) {
      wx.showModal({
        title: '语音功能未启用',
        content: '请在开发者工具或后台为小程序添加「微信同声传译」插件（WechatSI）。',
        showCancel: false
      })
      return
    }
    this._recognizedText = ''
    this._recognizeManager.start({ duration: 30000, lang: 'zh_CN' })
  },

  stopRecord() {
    if (!this._recognizeManager) return
    this._recognizeManager.stop()
  },

  cancelRecord() {
    if (!this._recognizeManager) return
    this._recognizeManager.stop()
    this._recognizedText = ''
  },

  // ---------------- 发送问题 ----------------
  async submit() {
    if (this.data.streaming) return
    const text = (this.data.question || '').trim()
    const attachments = this.data.pendingImages.slice()
    if (!text && attachments.length === 0) return

    const attachmentIds = attachments.map((a) => a.id)

    // 追加用户消息
    this._appendMessage({
      role: 'user',
      text: text,
      attachments: attachments
    })
    // 追加占位的 assistant 消息
    const assistantKey = this._appendMessage({
      role: 'assistant',
      text: '',
      references: [],
      streaming: true
    })

    this.setData({
      question: '',
      pendingImages: [],
      streaming: true
    })

    const references = []
    const seenRefs = {}

    this._currentTask = streamRequest(
      '/api/chat/stream',
      {
        question: text,
        conversation_id: this.data.conversationId,
        attachment_ids: attachmentIds
      },
      (evt) => {
        const name = evt.event
        const data = evt.data
        if (name === 'answer.delta' && typeof data === 'string') {
          this._appendAssistantDelta(assistantKey, data)
        } else if (name === 'answer.reference') {
          const title = (data.source_title || '').trim()
          if (!title) return
          const k = title + '|' + ((data.snippet || '').trim())
          if (seenRefs[k]) return
          seenRefs[k] = true
          references.push(data)
          this._updateAssistant(assistantKey, { references: references.slice() })
        } else if (name === 'answer.error') {
          this._updateAssistant(assistantKey, {
            text: '出错了：' + (data && (data.message || data)),
            streaming: false
          })
        }
      },
      () => {
        this._updateAssistant(assistantKey, { streaming: false })
        this.setData({ streaming: false })
        this._currentTask = null
      },
      (err) => {
        this._updateAssistant(assistantKey, {
          text: '请求失败：' + err.message,
          streaming: false
        })
        this.setData({ streaming: false })
        this._currentTask = null
      }
    )
  },

  // ---------------- 退出 ----------------
  logout() {
    wx.showModal({
      title: '提示',
      content: '确定退出登录？',
      success: (res) => {
        if (!res.confirm) return
        app.globalData.token = ''
        app.globalData.user = null
        wx.removeStorageSync('token')
        wx.removeStorageSync('user')
        wx.redirectTo({ url: '/pages/login/login' })
      }
    })
  }
})