"use client";

import { useState, useEffect } from "react";

export default function ThemeToggle() {
  const [isDark, setIsDark] = useState(true);

  useEffect(() => {
    const saved = localStorage.getItem("theme");
    if (saved === "light") {
      setIsDark(false);
      document.documentElement.classList.add("light");
      document.documentElement.classList.remove("dark");
    } else {
      setIsDark(true);
      document.documentElement.classList.add("dark");
      document.documentElement.classList.remove("light");
    }
  }, []);

  const toggle = () => {
    const next = !isDark;
    setIsDark(next);
    if (next) {
      document.documentElement.classList.add("dark");
      document.documentElement.classList.remove("light");
      localStorage.setItem("theme", "dark");
    } else {
      document.documentElement.classList.add("light");
      document.documentElement.classList.remove("dark");
      localStorage.setItem("theme", "light");
    }
  };

  return (
    <button
      onClick={toggle}
      className="fixed top-4 right-4 z-50 p-2 rounded-lg bg-zinc-200 dark:bg-zinc-800 hover:bg-zinc-300 dark:hover:bg-zinc-700 transition-colors border border-zinc-300 dark:border-zinc-700"
      aria-label="Toggle theme"
    >
      {isDark ? (
        <svg className="w-5 h-5 text-yellow-400" fill="none" viewBox="0 0 24 24" stroke="currentColor">
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 3v1m0 16v1m9-9h-1M4 12H3m15.364 6.364l-.707-.707M6.343 6.343l-.707-.707m12.728 0l-.707.707M6.343 17.657l-.707.707M16 12a4 4 0 11-8 0 4 4 0 018 0z" />
        </svg>
      ) : (
        <svg className="w-5 h-5 text-zinc-700" fill="none" viewBox="0 0 24 24" stroke="currentColor">
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M20.354 15.354A9 9 0 018.646 3.646 9.003 9.003 0 0012 21a9.003 9.003 0 008.354-5.646z" />
        </svg>
      )}
    </button>
  );
}
