'use client';

import { createContext, useContext, useEffect, useState, useCallback } from 'react';
import { User } from '@/types';
import { authApi } from '@/lib/api';

interface AuthContextType {
  user: User | null;
  token: string | null;
  loading: boolean;
  login: (username: string, password: string) => Promise<void>;
  logout: () => Promise<void>;
  setUser: (user: User) => void;
}

const AuthContext = createContext<AuthContextType | null>(null);

export function AuthProvider({ children }: { children: React.ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [token, setToken] = useState<string | null>(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    const storedToken = localStorage.getItem('auth_token');
    const storedUser = localStorage.getItem('auth_user');
    if (storedToken && storedUser) {
      setToken(storedToken);
      setUser(JSON.parse(storedUser));
    }
    setLoading(false);
  }, []);

  const login = useCallback(async (username: string, password: string) => {
    const res = await authApi.login(username, password);
    const { token: t, user: u } = res.data;
    localStorage.setItem('auth_token', t);
    localStorage.setItem('auth_user', JSON.stringify(u));
    setToken(t);
    setUser(u);
  }, []);

  const logout = useCallback(async () => {
    try {
      await authApi.logout();
    } catch {}
    localStorage.removeItem('auth_token');
    localStorage.removeItem('auth_user');
    setToken(null);
    setUser(null);
    window.location.href = '/auth';
  }, []);

  const updateUser = useCallback((u: User) => {
    setUser(u);
    localStorage.setItem('auth_user', JSON.stringify(u));
  }, []);

  return (
    <AuthContext.Provider value={{ user, token, loading, login, logout, setUser: updateUser }}>
      {children}
    </AuthContext.Provider>
  );
}

export function useAuth() {
  const ctx = useContext(AuthContext);
  if (!ctx) throw new Error('useAuth must be used within AuthProvider');
  return ctx;
}