const themeMod = require('./utils/theme')
const cloud = require('./utils/cloud')
const storage = require('./utils/storage')
const darkMod = require('./utils/darkMode')

App({
  async onLaunch() {
    // Init dark mode listener (refreshes all open pages when system theme changes)
    darkMod.watchDarkMode((isDark) => {
      const pages = getCurrentPages()
      pages.forEach(p => {
        if (p && typeof p.applyThemeToPage === 'function') {
          p.applyThemeToPage()
        }
      })
    })

    // Init cloud storage (no-op if not configured)
    cloud.init()

    const settings = wx.getStorageSync('user_settings')
    if (!settings) {
      wx.setStorageSync('user_settings', {
        planId: 'beginner',
        voiceGuide: true,
        vibrate: true,
        planStartDate: storage.getToday()
      })
    } else if (!settings.planStartDate) {
      // Migrate: add planStartDate for existing users
      settings.planStartDate = storage.getToday()
      wx.setStorageSync('user_settings', settings)
    }

    const streak = wx.getStorageSync('current_streak')
    if (!streak) {
      wx.setStorageSync('current_streak', { count: 0, lastDate: '' })
    }

    this.globalData.theme = themeMod.getCurrentTheme()

    // Sync with cloud: always locate our doc first (pullAll caches
    // _openid / _docId), then either restore or push. The previous flow
    // only pulled when local was empty, so on a cold start with non-empty
    // local it pushed without locating — and because the module-level
    // _openid / _docId caches had been reset, pushAll fell through to
    // add() and created a duplicate cloud doc every cold start. The
    // leaderboard then summed duration across N docs for the same user.
    const records = wx.getStorageSync('training_records')
    if (cloud.enabled) {
      try {
        const cloudData = await cloud.pullAll()
        const hasLocal = records && Object.keys(records).length > 0
        const hasCloud = cloudData && cloudData.records
          && Object.keys(cloudData.records).length > 0
          && Object.values(cloudData.records).some(arr => Array.isArray(arr) && arr.length > 0)

        // Parse cloud updatedAt into a comparable timestamp
        let cloudTs = 0
        if (cloudData && cloudData.updatedAt) {
          const d = cloudData.updatedAt instanceof Date
            ? cloudData.updatedAt
            : new Date(cloudData.updatedAt)
          cloudTs = d.getTime() || 0
        }
        const localSyncAt = wx.getStorageSync('_cloud_sync_at') || 0

        if (!hasLocal && hasCloud) {
          // Case 1: Fresh install on a new device — restore from cloud
          this._restoreFromCloud(cloudData)
          wx.setStorageSync('_cloud_sync_at', cloudTs)
        } else if (hasLocal && hasCloud) {
          // Case 2: Both sides have data — compare timestamps
          if (cloudTs > localSyncAt) {
            // Cloud is newer (another device synced after our last push)
            this._restoreFromCloud(cloudData)
            wx.setStorageSync('_cloud_sync_at', cloudTs)
          } else {
            // Local is at least as current — push
            cloud.pushAll()
          }
        } else if (hasLocal && !hasCloud) {
          // Case 3: Only local data (first-ever sync) — push
          cloud.pushAll()
        }
        // else: no data anywhere — nothing to sync
      } catch (e) {
        console.error('Cloud sync on launch failed:', e)
      }
    }
  },

  _restoreFromCloud(cloudData) {
    if (!cloudData) return
    try {
      if (cloudData.records && Object.keys(cloudData.records).length > 0) {
        // Guard: only restore if at least one month has actual records.
        // Pre-6d19928 duplicates could leave docs with month keys but
        // empty arrays, which would wipe local data on restore.
        const hasAny = Object.values(cloudData.records).some(
          arr => Array.isArray(arr) && arr.length > 0
        )
        if (hasAny) {
          wx.setStorageSync('training_records', cloudData.records)
        }
      }
      if (cloudData.settings) {
        wx.setStorageSync('user_settings', cloudData.settings)
      }
      if (cloudData.streak) {
        wx.setStorageSync('current_streak', cloudData.streak)
      }
      if (cloudData.customPlans && typeof cloudData.customPlans === 'object') {
        wx.setStorageSync('custom_plans', cloudData.customPlans)
      }
      if (cloudData.profile && typeof cloudData.profile === 'object') {
        wx.setStorageSync('user_profile', cloudData.profile)
      }
      if (cloudData.themeId) {
        themeMod.setTheme(cloudData.themeId)
      }
    } catch (e) {
      console.error('Cloud restore failed:', e)
    }
  },

  globalData: {
    planId: 'beginner',
    theme: null
  }
})