import { computed, ref } from 'vue'

const THEME_SKIN_STORAGE_KEY = 'x-financial-theme-skin'
const DEFAULT_THEME_SKIN_ID = 'enterprise'

const DEFAULT_SEMANTIC_COLORS = {
  success: '#2f855a',
  successHover: '#276749',
  successActive: '#22543d',
  successSoft: '#f0f7f2',
  successLine: '#cde6d5',
  warning: '#b7791f',
  warningHover: '#975a16',
  warningActive: '#7b4514',
  warningSoft: '#fff8eb',
  warningLine: '#efd9af',
  danger: '#dc2626',
  dangerHover: '#b91c1c',
  dangerActive: '#991b1b',
  dangerSoft: '#fef2f2',
  dangerLine: '#fecaca',
  info: '#475569',
  infoHover: '#334155',
  infoActive: '#1e293b',
  infoSoft: '#f1f5f9',
  infoLine: '#cbd5e1'
}

export const THEME_SKIN_OPTIONS = [
  {
    id: 'vivid',
    label: '动感活泼',
    desc: '保留当前 AI 助手的明快节奏，适合演示、培训和轻量工作台。',
    keywords: ['明快', '渐变', '助手感'],
    primary: '#2f7cff',
    primaryHover: '#2563eb',
    primaryActive: '#1d4ed8',
    primarySoft: '#eef6ff',
    primarySoftStrong: '#dbeafe',
    secondary: '#7c5cff',
    chartBlue: '#2f7cff',
    chartPurple: '#7c5cff',
    chartAmber: '#f59e0b'
  },
  {
    id: 'enterprise',
    label: '企业沉稳',
    desc: '低饱和、轻描边、少渲染，适合正式生产环境和企业级财务 SaaS。',
    keywords: ['克制', '结构化', '低噪声'],
    primary: '#475569',
    primaryHover: '#3f4a5a',
    primaryActive: '#334155',
    primarySoft: '#f1f5f9',
    primarySoftStrong: '#e2e8f0',
    secondary: '#64748b',
    chartBlue: '#5d7590',
    chartPurple: '#6b7280',
    chartAmber: '#9a7a45'
  },
  {
    id: 'intelligent',
    label: '专业智能',
    desc: '保留少量智能识别感，同时控制饱和度，适合稳定办公和 AI 辅助并重的团队。',
    keywords: ['智能', '专业', '轻点缀'],
    primary: '#5f6f9f',
    primaryHover: '#53618b',
    primaryActive: '#465275',
    primarySoft: '#f3f4fb',
    primarySoftStrong: '#e2e5f4',
    secondary: '#477c9e',
    chartBlue: '#4f7495',
    chartPurple: '#6d6a9f',
    chartAmber: '#a98857'
  }
]

const activeThemeSkinId = ref(DEFAULT_THEME_SKIN_ID)
const THEME_MODE_IDS = new Set(THEME_SKIN_OPTIONS.map((skin) => skin.id))
const LEGACY_THEME_MODE_MAP = {
  sky: 'vivid',
  blue: 'vivid',
  emerald: 'vivid',
  teal: 'vivid',
  'legacy-green': 'vivid',
  navy: 'enterprise',
  slate: 'enterprise',
  sage: 'enterprise',
  gray: 'enterprise',
  grey: 'enterprise',
  purple: 'intelligent',
  violet: 'intelligent',
  'soft-violet': 'intelligent'
}

export function normalizeThemeMode(value) {
  const normalized = String(value ?? '').trim()

  if (THEME_MODE_IDS.has(normalized)) {
    return normalized
  }

  return LEGACY_THEME_MODE_MAP[normalized] || DEFAULT_THEME_SKIN_ID
}

function findThemeSkin(id) {
  const themeMode = normalizeThemeMode(id)
  return THEME_SKIN_OPTIONS.find((skin) => skin.id === themeMode) || THEME_SKIN_OPTIONS[0]
}

function hexToRgb(hex) {
  const normalized = String(hex || '').replace('#', '')
  const value = normalized.length === 3
    ? normalized.split('').map((item) => item + item).join('')
    : normalized
  const numberValue = Number.parseInt(value, 16)

  if (!Number.isFinite(numberValue) || value.length !== 6) {
    return '58, 124, 165'
  }

  return [
    (numberValue >> 16) & 255,
    (numberValue >> 8) & 255,
    numberValue & 255
  ].join(', ')
}

function setVariables(root, variables) {
  Object.entries(variables).forEach(([key, value]) => {
    root.style.setProperty(key, value)
  })
}

function applyThemeSkin(skin) {
  if (typeof document === 'undefined') {
    return
  }

  const root = document.documentElement
  const primaryRgb = hexToRgb(skin.primary)
  const secondaryRgb = hexToRgb(skin.secondary)
  const successRgb = hexToRgb(DEFAULT_SEMANTIC_COLORS.success)
  const warningRgb = hexToRgb(DEFAULT_SEMANTIC_COLORS.warning)
  const dangerRgb = hexToRgb(DEFAULT_SEMANTIC_COLORS.danger)
  const infoRgb = hexToRgb(DEFAULT_SEMANTIC_COLORS.info)

  root.dataset.themeSkin = skin.id
  root.dataset.themeMode = skin.id

  setVariables(root, {
    '--primary': skin.primary,
    '--primary-hover': skin.primaryHover,
    '--primary-active': skin.primaryActive,
    '--primary-soft': skin.primarySoft,
    '--primary-soft-strong': skin.primarySoftStrong,
    '--primary-rgb': primaryRgb,
    '--secondary': skin.secondary,
    '--secondary-rgb': secondaryRgb,
    '--theme-secondary': skin.secondary,
    '--theme-secondary-rgb': secondaryRgb,
    '--theme-primary': skin.primary,
    '--theme-primary-hover': skin.primaryHover,
    '--theme-primary-active': skin.primaryActive,
    '--theme-primary-soft': skin.primarySoft,
    '--theme-primary-soft-strong': skin.primarySoftStrong,
    '--theme-primary-light-5': 'color-mix(in srgb, var(--theme-primary) 46%, white)',
    '--theme-primary-light-9': 'color-mix(in srgb, var(--theme-primary) 8%, white)',
    '--theme-primary-rgb': primaryRgb,
    '--theme-primary-shadow': `rgba(${primaryRgb}, 0.16)`,
    '--theme-focus-ring': `rgba(${primaryRgb}, 0.12)`,
    '--theme-gradient-primary': `linear-gradient(135deg, ${skin.primary}, ${skin.primaryActive})`,
    '--chart-primary': skin.primary,
    '--chart-primary-rgb': primaryRgb,
    '--chart-blue': skin.chartBlue,
    '--chart-purple': skin.chartPurple,
    '--chart-amber': skin.chartAmber,
    '--success': DEFAULT_SEMANTIC_COLORS.success,
    '--success-hover': DEFAULT_SEMANTIC_COLORS.successHover,
    '--success-active': DEFAULT_SEMANTIC_COLORS.successActive,
    '--success-soft': DEFAULT_SEMANTIC_COLORS.successSoft,
    '--success-line': DEFAULT_SEMANTIC_COLORS.successLine,
    '--success-rgb': successRgb,
    '--warning': DEFAULT_SEMANTIC_COLORS.warning,
    '--warning-hover': DEFAULT_SEMANTIC_COLORS.warningHover,
    '--warning-active': DEFAULT_SEMANTIC_COLORS.warningActive,
    '--warning-soft': DEFAULT_SEMANTIC_COLORS.warningSoft,
    '--warning-line': DEFAULT_SEMANTIC_COLORS.warningLine,
    '--warning-rgb': warningRgb,
    '--danger': DEFAULT_SEMANTIC_COLORS.danger,
    '--danger-hover': DEFAULT_SEMANTIC_COLORS.dangerHover,
    '--danger-active': DEFAULT_SEMANTIC_COLORS.dangerActive,
    '--danger-soft': DEFAULT_SEMANTIC_COLORS.dangerSoft,
    '--danger-line': DEFAULT_SEMANTIC_COLORS.dangerLine,
    '--danger-rgb': dangerRgb,
    '--info': DEFAULT_SEMANTIC_COLORS.info,
    '--info-hover': DEFAULT_SEMANTIC_COLORS.infoHover,
    '--info-active': DEFAULT_SEMANTIC_COLORS.infoActive,
    '--info-soft': DEFAULT_SEMANTIC_COLORS.infoSoft,
    '--info-line': DEFAULT_SEMANTIC_COLORS.infoLine,
    '--info-rgb': infoRgb,
    '--el-color-primary': skin.primary,
    '--el-color-primary-dark-2': skin.primaryActive,
    '--el-color-primary-light-3': skin.primaryHover,
    '--el-color-primary-light-5': 'var(--theme-primary-light-5)',
    '--el-color-primary-light-7': skin.primarySoftStrong,
    '--el-color-primary-light-8': skin.primarySoft,
    '--el-color-primary-light-9': 'var(--theme-primary-light-9)'
  })
}

function readStoredThemeSkinId() {
  if (typeof window === 'undefined') {
    return DEFAULT_THEME_SKIN_ID
  }

  const stored = window.localStorage.getItem(THEME_SKIN_STORAGE_KEY)
  return findThemeSkin(stored).id
}

export function installThemeSkin() {
  const skin = findThemeSkin(readStoredThemeSkinId())
  activeThemeSkinId.value = skin.id
  applyThemeSkin(skin)
}

export function setThemeSkin(id) {
  const skin = findThemeSkin(id)
  activeThemeSkinId.value = skin.id
  applyThemeSkin(skin)

  if (typeof window !== 'undefined') {
    window.localStorage.setItem(THEME_SKIN_STORAGE_KEY, skin.id)
  }

  return skin.id
}

export function useThemeSkin() {
  return {
    activeThemeSkin: computed(() => findThemeSkin(activeThemeSkinId.value)),
    activeThemeSkinId,
    setThemeSkin,
    themeSkinOptions: THEME_SKIN_OPTIONS
  }
}