import { createContext, useContext, useEffect, useMemo, useState, type ReactNode } from "react";
import type { Session, User } from "@supabase/supabase-js";
import { supabase } from "@/integrations/supabase/client";

type AuthValue = {
  user: User | null;
  session: Session | null;
  loading: boolean;
};

const AuthContext = createContext<AuthValue>({ user: null, session: null, loading: true });

export function AuthProvider({ children }: { children: ReactNode }) {
  const [session, setSession] = useState<Session | null>(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    const { data: sub } = supabase.auth.onAuthStateChange((_event, next) => {
      setSession(next);
      setLoading(false);
    });
    supabase.auth.getSession().then(({ data }) => {
      setSession(data.session);
      setLoading(false);
    });
    return () => sub.subscription.unsubscribe();
  }, []);

  const value = useMemo<AuthValue>(
    () => ({ session, user: session?.user ?? null, loading }),
    [session, loading],
  );

  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
}

export function useAuth(): AuthValue {
  return useContext(AuthContext);
}