'use client'

import * as React from 'react'
import { Moon, Sun } from 'lucide-react'
import { useTheme } from 'next-themes'
import { Button } from '@/components/ui/button'

export function ThemeToggle() {
  const { resolvedTheme, setTheme } = useTheme()
  const [mounted, setMounted] = React.useState(false)

  React.useEffect(() => {
    setMounted(true)
  }, [])

  if (!mounted) {
    return null
  }

  const isDark = resolvedTheme === 'dark'

  return (
    <Button
      type="button"
      variant="outline"
      size="icon"
      onClick={() => setTheme(isDark ? 'light' : 'dark')}
      className="fixed top-4 right-4 z-50"
      aria-label="Toggle theme"
      title={isDark ? '切换到浅色模式' : '切换到深色模式'}
    >
      {isDark ? <Sun /> : <Moon />}
    </Button>
  )
}