import { mockChatHistory } from '../../utils/mock-data'
import { sortByTimestamp } from '../../utils/sort'
import { formatRelativeTime } from '../../utils/time'

/** VI 规范 §6.2：AI 图标配色系统（6种） */
const ICON_GRADIENTS = [
  'linear-gradient(135deg, #667eea 0%, #4a5fc7 100%)', // indigo
  'linear-gradient(135deg, #764ba2 0%, #5b3080 100%)', // purple
  'linear-gradient(135deg, #e74c3c 0%, #c0392b 100%)', // red
  'linear-gradient(135deg, #e67e22 0%, #ca6c17 100%)', // orange
  'linear-gradient(135deg, #d4a017 0%, #b8860b 100%)', // yellow
  'linear-gradient(135deg, #2980b9 0%, #1a5276 100%)', // blue
]

/** 带展示标签的对话历史项 */
interface ChatHistoryDisplay {
  id: string
  title: string
  lastMessage: string
  timestamp: string
  customerName?: string
  /** 格式化后的时间标签 */
  timeLabel: string
  /** 图标背景渐变（VI §6.2 AI 图标配色，每条随机） */
  iconGradient: string
}

Page({
  data: {
    /** 页面状态：loading / empty / normal / error */
    pageState: 'loading' as 'loading' | 'empty' | 'normal' | 'error',
    /** 状态栏高度 */
    statusBarHeight: 0,
    /** 对话历史列表 */
    list: [] as ChatHistoryDisplay[],
  },

  onLoad() {
    const sysInfo = wx.getWindowInfo()
    this.setData({ statusBarHeight: sysInfo.statusBarHeight || 44 })
    this.loadData()
  },

  /** 加载数据 */
  loadData() {
    this.setData({ pageState: 'loading' })

    try {
      setTimeout(() => {
        // TODO: 替换为真实 API 调用
        const sorted = sortByTimestamp(mockChatHistory)
        const list: ChatHistoryDisplay[] = sorted.map((item) => ({
          ...item,
          timeLabel: formatRelativeTime(item.timestamp),
          iconGradient: ICON_GRADIENTS[Math.floor(Math.random() * ICON_GRADIENTS.length)],
        }))

        this.setData({
          list,
          pageState: list.length === 0 ? 'empty' : 'normal',
        })
      }, 400)
    } catch {
      this.setData({ pageState: 'error' })
    }
  },

  /** 返回上一页 */
  onBack() {
    wx.navigateBack()
  },

  /** 重试加载 */
  onRetry() {
    this.loadData()
  },

  /** 点击对话记录 → 跳转 chat 页面 */
  onItemTap(e: WechatMiniprogram.TouchEvent) {
    const id = e.currentTarget.dataset.id
    wx.navigateTo({ url: '/pages/chat/chat?historyId=' + id })
  },

  /** 下拉刷新 */
  onPullDownRefresh() {
    this.loadData()
    setTimeout(() => wx.stopPullDownRefresh(), 600)
  },
})