export const GUANGHU_THEME_STORAGE_KEY = 'guanghu-theme'

export const GUANGHU_THEMES = ['native', 'lake-light', 'lake-dark'] as const
export type GuanghuTheme = typeof GUANGHU_THEMES[number]

export const GUANGHU_THEME_LABELS: Record<GuanghuTheme, string> = {
  native: '原生',
  'lake-light': '湖光浅色',
  'lake-dark': '湖心深色',
}

export function normalizeGuanghuTheme(value: unknown): GuanghuTheme {
  return typeof value === 'string' && (GUANGHU_THEMES as readonly string[]).includes(value)
    ? value as GuanghuTheme
    : 'native'
}

export function readGuanghuTheme(storage: Pick<Storage, 'getItem'>): GuanghuTheme {
  try {
    return normalizeGuanghuTheme(storage.getItem(GUANGHU_THEME_STORAGE_KEY))
  } catch {
    return 'native'
  }
}

export function writeGuanghuTheme(storage: Pick<Storage, 'setItem'>, theme: GuanghuTheme): void {
  try {
    storage.setItem(GUANGHU_THEME_STORAGE_KEY, theme)
  } catch {
    // Storage may be unavailable in restricted browser contexts.
  }
}