/*
Copyright (C) 2023-2026 QuantumNous

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.

For commercial licensing, please contact support@quantumnous.com
*/
import { useCallback } from 'react'
import { Languages, Check } from 'lucide-react'
import { useTranslation } from 'react-i18next'
import { useAuthStore } from '@/stores/auth-store'
import { api } from '@/lib/api'
import { cn } from '@/lib/utils'
import { Button } from '@/components/ui/button'
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from '@/components/ui/dropdown-menu'

const languages = [
  { code: 'en', label: 'English' },
  { code: 'zh', label: '中文' },
  { code: 'fr', label: 'Français' },
  { code: 'ru', label: 'Русский' },
  { code: 'ja', label: '日本語' },
  { code: 'vi', label: 'Tiếng Việt' },
]

export function LanguageSwitcher() {
  const { i18n, t } = useTranslation()
  const user = useAuthStore((s) => s.auth.user)

  const handleChangeLanguage = useCallback(
    async (code: string) => {
      await i18n.changeLanguage(code)
      if (user) {
        try {
          await api.put('/api/user/self', { language: code })
        } catch {
          // Best-effort persistence; don't block the UI on failure
        }
      }
    },
    [i18n, user]
  )

  return (
    <DropdownMenu modal={false}>
      <DropdownMenuTrigger
        render={<Button variant='ghost' size='icon' className='h-9 w-9' />}
      >
        <Languages className='size-[1.2rem]' />
        <span className='sr-only'>{t('Change language')}</span>
      </DropdownMenuTrigger>
      <DropdownMenuContent align='end'>
        {languages.map((lang) => (
          <DropdownMenuItem
            key={lang.code}
            onClick={() => handleChangeLanguage(lang.code)}
          >
            {lang.label}
            <Check
              size={14}
              className={cn('ms-auto', i18n.language !== lang.code && 'hidden')}
            />
          </DropdownMenuItem>
        ))}
      </DropdownMenuContent>
    </DropdownMenu>
  )
}