frontend/src/components/ui/ThemeToggle.tsx

import { Button } from "@/components/ui/button";
import { DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuTrigger } from "@/components/ui/dropdown-menu";
import { Laptop, Moon, Sun } from "lucide-react";
import { useTheme } from "next-themes";

export function ThemeToggle() {
  const { setTheme } = useTheme();

  return (
    <DropdownMenu>
      <DropdownMenuTrigger asChild>
        <Button variant="ghost" size="icon">
          <Sun className="h-[1.2rem] w-[1.2rem] rotate-0 transition-all dark:-rotate-90 dark:hidden" />
          <Moon className="absolute h-[1.2rem] w-[1.2rem] hidden rotate-90 transition-all dark:rotate-0 dark:block" />
          <span className="sr-only">Toggle theme</span>
        </Button>
      </DropdownMenuTrigger>
      <DropdownMenuContent align="end">
        <DropdownMenuItem onClick={() => setTheme("light")}>
          <Sun className="mr-2 h-4 w-4" />
          <span>Light</span>
        </DropdownMenuItem>
        <DropdownMenuItem onClick={() => setTheme("dark")}>
          <Moon className="mr-2 h-4 w-4" />
          <span>Dark</span>
        </DropdownMenuItem>
        <DropdownMenuItem onClick={() => setTheme("system")}>
          <Laptop className="mr-2 h-4 w-4" />
          <span>System</span>
        </DropdownMenuItem>
      </DropdownMenuContent>
    </DropdownMenu>
  );
}