"use client";

import { useTheme } from "next-themes";
import { Moon, Sun } from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
} from "@/components/ui/tooltip";
import { useSyncExternalStore } from "react";

const emptySubscribe = () => () => {};

function useMounted() {
  return useSyncExternalStore(
    emptySubscribe,
    () => true,
    () => false,
  );
}

export function ThemeToggle() {
  const { resolvedTheme, setTheme } = useTheme();
  const mounted = useMounted();

  // Avoid hydration mismatch — on the server and during hydration, render a placeholder
  if (!mounted) {
    return (
      <Button variant="ghost" size="icon-sm" aria-label="Toggle theme">
        <Sun className="size-4" />
      </Button>
    );
  }

  const isDark = resolvedTheme === "dark";

  return (
    <Tooltip>
      <TooltipTrigger
        render={
          <Button
            variant="ghost"
            size="icon-sm"
            onClick={() => setTheme(isDark ? "light" : "dark")}
            aria-label={isDark ? "Switch to light mode" : "Switch to dark mode"}
          />
        }
      >
        {isDark ? <Sun className="size-4" /> : <Moon className="size-4" />}
      </TooltipTrigger>
      <TooltipContent side="bottom">
        {isDark ? "Light mode" : "Dark mode"}
      </TooltipContent>
    </Tooltip>
  );
}