"use client";

import {
  createContext,
  useContext,
  useEffect,
  useState,
  ReactNode,
} from "react";

type Theme = "light" | "dark";

interface ThemeContextType {
  theme: Theme;
  setTheme: (theme: Theme) => void;
  toggleTheme: () => void;
}

const ThemeContext = createContext<ThemeContextType | undefined>(undefined);

export function ThemeProvider({ children }: { children: ReactNode }) {
  const [theme, setTheme] = useState<Theme>("light");

  useEffect(() => {
    const savedTheme = localStorage.getItem("theme") as Theme | null;
    if (savedTheme) {
      setTheme(savedTheme);
      document.documentElement.classList.toggle("dark", savedTheme === "dark");
    } else {
      const prefersDark = window.matchMedia(
        "(prefers-color-scheme: dark)",
      ).matches;
      const initialTheme = prefersDark ? "dark" : "light";
      setTheme(initialTheme);
      document.documentElement.classList.toggle("dark", prefersDark);
    }
  }, []);

  const toggleTheme = () => {
    const newTheme = theme === "light" ? "dark" : "light";
    setTheme(newTheme);
    localStorage.setItem("theme", newTheme);
    document.documentElement.classList.toggle("dark", newTheme === "dark");
  };

  const handleSetTheme = (newTheme: Theme) => {
    setTheme(newTheme);
    localStorage.setItem("theme", newTheme);
    document.documentElement.classList.toggle("dark", newTheme === "dark");
  };

  return (
    <ThemeContext.Provider
      value={{ theme, setTheme: handleSetTheme, toggleTheme }}
    >
      <div className={theme}>{children}</div>
    </ThemeContext.Provider>
  );
}

export function useTheme() {
  const context = useContext(ThemeContext);
  if (context === undefined) {
    throw new Error("useTheme must be used within a ThemeProvider");
  }
  return context;
}