const THEMES = [
  {
    id: 'orange',
    name: '活力橙',
    primary: '#FF6B35',
    primaryLight: '#FF8C5A',
    primaryBg: '#FFF3ED',
    primaryRgb: '255,107,53'
  },
  {
    id: 'blue',
    name: '深海蓝',
    primary: '#2979FF',
    primaryLight: '#5C9CFF',
    primaryBg: '#EDF4FF',
    primaryRgb: '41,121,255'
  },
  {
    id: 'green',
    name: '森林绿',
    primary: '#43A047',
    primaryLight: '#6EC072',
    primaryBg: '#EDF7EE',
    primaryRgb: '67,160,71'
  },
  {
    id: 'purple',
    name: '优雅紫',
    primary: '#7E57C2',
    primaryLight: '#A08AD6',
    primaryBg: '#F5F0FA',
    primaryRgb: '126,87,194'
  },
  {
    id: 'pink',
    name: '樱花粉',
    primary: '#EC407A',
    primaryLight: '#F06A9A',
    primaryBg: '#FDEEF3',
    primaryRgb: '236,64,122'
  }
]

// Light-mode base CSS custom properties shared between the cold-start export
// (used by every page as initial data) and getThemeStyle(isDark=false).
// Update here ONLY — getThemeStyle picks it up for the light branch.
const BASE_VARS = '--text:#333333;--text-secondary:#999999;--bg:#F5F5F5;--bg-gradient-start:#F5F5F5;--bg-gradient-end:#FAFAFA;--card-bg:#FFFFFF;--bg-soft:#F0F0F0;--border:#EEEEEE;--success:#4CAF50;--success-rgb:76,175,80;--danger:#E53935;--danger-rgb:229,57,53;'
const DEFAULT_THEME_ID = 'orange'
const THEME_KEY = 'app_theme'

const getThemeById = (id) => THEMES.find(t => t.id === id) || THEMES[0]

const getCurrentTheme = () => {
  let id = wx.getStorageSync(THEME_KEY)
  if (!id) {
    // fallback: try recovering from user_settings backup
    try {
      const s = wx.getStorageSync('user_settings')
      if (s && s.themeId) id = s.themeId
    } catch (e) {}
  }
  return getThemeById(id || DEFAULT_THEME_ID)
}

const _setNavBarColor = (primary) => {
  try {
    wx.setNavigationBarColor({
      frontColor: '#ffffff',
      backgroundColor: primary
    })
  } catch (e) {}
}

const setTheme = (id) => {
  try {
    wx.setStorageSync(THEME_KEY, id)
    // redundant backup in user_settings
    try {
      const s = wx.getStorageSync('user_settings') || {}
      s.themeId = id
      wx.setStorageSync('user_settings', s)
    } catch (e) {}
  } catch (e) {
    console.error('Failed to save theme:', e)
  }
  const theme = getThemeById(id)
  _setNavBarColor(theme.primary)
  const app = getApp()
  if (app && app.globalData) app.globalData.theme = theme

  // sync to cloud (lazy-require to avoid circular deps)
  try { require('./cloud').pushAll() } catch (e) {}
  return theme
}

const getThemeStyle = (theme, isDark = false) => {
  const t = theme || getCurrentTheme()
  const baseVars = isDark
    ? '--text:#E5E5E7;--text-secondary:#98989F;--bg:#2C2C2E;--bg-gradient-start:#2C2C2E;--bg-gradient-end:#38383A;--card-bg:#3A3A3C;--bg-soft:#48484A;--border:#48484A;--success:#30D158;--success-rgb:48,209,88;--danger:#FF6B6B;--danger-rgb:255,107,107;'
    : BASE_VARS
  return `${baseVars}--primary:${t.primary};--primary-light:${t.primaryLight};--primary-bg:${t.primaryBg};--primary-rgb:${t.primaryRgb};`
}

const applyThemeToPage = (self) => {
  const darkMod = require('./darkMode')
  const theme = getCurrentTheme()
  const isDark = darkMod.getInitialDarkMode()
  const nextStyle = getThemeStyle(theme, isDark)
  // Skip setData if nothing changed — avoid unnecessary re-renders on every onShow
  if (self.data && self.data.themeStyle === nextStyle) {
    return
  }
  self.setData({ theme, themeStyle: nextStyle, isDark })
  _setNavBarColor(theme.primary)

  // theme.json 的 dark section 只响应系统暗黑模式。用户手动选择暗黑
  // 但系统是明亮时,窗口背景仍为浅色,切 tab 会闪白。这里用 API 强制设置
  // 窗口背景,让 tab 切换时的瞬间底色与当前模式一致。
  const bg = isDark ? '#0F0F12' : '#F5F5F5'
  try { wx.setBackgroundColor({ backgroundColor: bg, backgroundColorTop: bg, backgroundColorBottom: bg }) } catch (e) {}
}

/** 仅设置窗口背景色,不触发页面 setData — 供 app.js 冷启动使用 */
const applyWindowBg = () => {
  try {
    const darkMod = require('./darkMode')
    const isDark = darkMod.getInitialDarkMode()
    const bg = isDark ? '#0F0F12' : '#F5F5F5'
    wx.setBackgroundColor({ backgroundColor: bg, backgroundColorTop: bg, backgroundColorBottom: bg })
  } catch (e) {}
}

module.exports = {
  THEMES,
  DEFAULT_THEME_ID,
  BASE_VARS,
  applyWindowBg,
  getThemeById,
  getCurrentTheme,
  setTheme,
  applyThemeToPage,
  getThemeStyle
}