'use client';

import { useRouter } from 'next/navigation';
import { useEffect, useState, useCallback } from 'react';
import {
  login as apiLogin,
  getCurrentUser,
  setTokens,
  clearTokens,
  isAuthenticated,
  type UserResponse,
  type ApiError,
} from './api';

export interface AuthState {
  user: UserResponse | null;
  loading: boolean;
  error: string | null;
}

export function useAuth() {
  const [state, setState] = useState<AuthState>({
    user: null,
    loading: true,
    error: null,
  });

  const fetchUser = useCallback(async () => {
    if (!isAuthenticated()) {
      setState({ user: null, loading: false, error: null });
      return;
    }
    try {
      const user = await getCurrentUser();
      setState({ user, loading: false, error: null });
    } catch {
      clearTokens();
      setState({ user: null, loading: false, error: 'Session expired' });
    }
  }, []);

  useEffect(() => {
    fetchUser();
  }, [fetchUser]);

  const login = useCallback(async (email: string, password: string) => {
    setState({ user: null, loading: true, error: null });
    try {
      const tokens = await apiLogin(email, password);
      setTokens(tokens);
      const user = await getCurrentUser();
      setState({ user, loading: false, error: null });
      return user;
    } catch (err) {
      const message = (err as ApiError)?.error?.message || 'Login failed';
      setState({ user: null, loading: false, error: message });
      throw err;
    }
  }, []);

  const logout = useCallback(() => {
    clearTokens();
    setState({ user: null, loading: false, error: null });
  }, []);

  return { ...state, login, logout, refresh: fetchUser };
}

export function useRequireAuth() {
  const auth = useAuth();
  const router = useRouter();

  useEffect(() => {
    if (!auth.loading && !auth.user) {
      router.push('/login');
    }
  }, [auth.loading, auth.user, router]);

  return auth;
}