app/frontend/src/components/ui/theme-toggle.js

import React from "react";
import { useTheme } from "./theme-provider";
import { Button } from "./button";

export function ThemeToggle({ className }) {
  const { theme, toggleTheme } = useTheme();

  return (
    <Button
      variant="ghost"
      size="icon"
      onClick={toggleTheme}
      className={className}
      aria-label="Toggle theme"
    >
      {theme === "light" ? (
        <svg
          xmlns="http://www.w3.org/2000/svg"
          width="20"
          height="20"
          viewBox="0 0 24 24"
          fill="none"
          stroke="currentColor"
          strokeWidth="2"
          strokeLinecap="round"
          strokeLinejoin="round"
          className="lucide lucide-moon"
        >
          <path d="M12 3a6 6 0 0 0 9 9 9 9 0 1 1-9-9Z" />
        </svg>
      ) : (
        <svg
          xmlns="http://www.w3.org/2000/svg"
          width="20"
          height="20"
          viewBox="0 0 24 24"
          fill="none"
          stroke="currentColor"
          strokeWidth="2"
          strokeLinecap="round"
          strokeLinejoin="round"
          className="lucide lucide-sun"
        >
          <circle cx="12" cy="12" r="4" />
          <path d="M12 2v2" />
          <path d="M12 20v2" />
          <path d="m4.93 4.93 1.41 1.41" />
          <path d="m17.66 17.66 1.41 1.41" />
          <path d="M2 12h2" />
          <path d="M20 12h2" />
          <path d="m6.34 17.66-1.41 1.41" />
          <path d="m19.07 4.93-1.41 1.41" />
        </svg>
      )}
    </Button>
  );
}