const themeMod = require('../../utils/theme')
const iconsMod = require('../../utils/icons')
const util = require('../../utils/util')
const storage = require('../../utils/storage')
const config = require('../../config')

Page({
  data: {
    theme: { primary: '#FF6B35', primaryLight: '#FF8C5A', primaryBg: '#FFF3ED', primaryRgb: '255,107,53' },
    themeStyle: themeMod.BASE_VARS,
    periods: [
      { key: 'day', label: '日榜' },
      { key: 'month', label: '月榜' },
      { key: 'year', label: '年榜' }
    ],
    activePeriod: 'day',
    rankedList: [],
    myEntry: null,
    loading: false,
    empty: false,
    icons: iconsMod.build()
  },

  onLoad() {
    themeMod.applyThemeToPage(this)
    this._firstShow = true
  },

  onShow() {
    themeMod.applyThemeToPage(this)
    const theme = themeMod.getCurrentTheme()
    this.setData({ theme, icons: iconsMod.build(theme) })
    try {
      const tb = this.getTabBar()
      if (tb) tb.setData({ selected: 2 })
    } catch (e) {}
    if (this._firstShow) {
      this._firstShow = false
      this.fetchRank()
      return
    }
    this.fetchRank()
  },

  onPullDownRefresh() {
    this.fetchRank(() => wx.stopPullDownRefresh())
  },

  switchPeriod(e) {
    const period = e.currentTarget.dataset.period
    if (period === this.data.activePeriod) return
    this.setData({ activePeriod: period, rankedList: [], myEntry: null })
    this.fetchRank()
  },

  fetchRank(cb) {
    this.setData({ loading: true, empty: false })
    wx.cloud.callFunction({
      name: 'leaderboard',
      data: {
        period: this.data.activePeriod,
        maxRank: config.leaderboardMaxRank
      }
    }).then(res => {
      this._applyResult(res.result || {})
      if (cb) cb()
    }).catch((err) => {
      // Cloud function not deployed or network error — fall back to
      // local data but let the user know the leaderboard is degraded.
      console.warn('[leaderboard] cloud function failed, using local fallback:', err)
      wx.showToast({ title: '云端榜单暂不可用', icon: 'none', duration: 2000 })
      this._applyLocal()
      if (cb) cb()
    })
  },

  _applyResult(result) {
    const list = (result.ranked || []).map(item => ({
      ...item,
      durationText: util.formatDuration(item.duration)
    }))
    const myEntry = result.myEntry ? {
      ...result.myEntry,
      durationText: util.formatDuration(result.myEntry.duration),
      isMe: true
    } : null
    this.setData({
      rankedList: list,
      myEntry,
      loading: false,
      empty: list.length === 0 && !myEntry
    })
  },

  /** Local fallback: use local storage when cloud function isn't deployed */
  _applyLocal() {
    const period = this.data.activePeriod
    const allRecords = Object.values(storage.getRecords()).flat()
    const today = storage.getToday()
    const thisMonth = today.substring(0, 7)
    const thisYear = String(new Date().getFullYear())
    const profile = storage.getProfile()
    const localName = profile.nickname || '我'

    let duration = 0
    let sessions = 0
    allRecords.forEach(r => {
      if (period === 'day' && util.dateOnly(r.date) === util.dateOnly(today)) { duration += r.duration; sessions++ }
      if (period === 'month' && r.date.startsWith(thisMonth)) { duration += r.duration; sessions++ }
      if (period === 'year' && r.date.startsWith(thisYear)) { duration += r.duration; sessions++ }
    })

    if (duration > 0) {
      const entry = {
        rank: 1, openid: 'local', name: localName, nickname: profile.nickname || '',
        duration, durationText: util.formatDuration(duration), sessions
      }
      this.setData({ rankedList: [entry], myEntry: { ...entry, isMe: true }, loading: false, empty: false })
    } else {
      this.setData({ loading: false, empty: true })
    }
  }
})