"use client";

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

type Theme = "light" | "dark" | "senior";

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

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

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

  useEffect(() => {
    // Load theme from localStorage on mount
    const savedTheme = localStorage.getItem("theme") as Theme;
    if (savedTheme) {
      setThemeState(savedTheme);
      applyTheme(savedTheme);
    }
  }, []);

  const setTheme = (newTheme: Theme) => {
    setThemeState(newTheme);
    localStorage.setItem("theme", newTheme);
    applyTheme(newTheme);
  };

  const applyTheme = (theme: Theme) => {
    const root = document.documentElement;

    // Remove all theme classes
    root.classList.remove("light", "dark", "senior");

    // Add new theme class
    root.classList.add(theme);
  };

  return (
    <ThemeContext.Provider value={{ theme, setTheme }}>
      {children}
    </ThemeContext.Provider>
  );
}

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