import { useState, useEffect, createContext, useContext } from 'react';
import { api } from '../services/api';
import toast from 'react-hot-toast';

const AuthContext = createContext();

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

export const AuthProvider = ({ children }) => {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    const token = localStorage.getItem('token');
    if (token) {
      api.defaults.headers.common['Authorization'] = `Bearer ${token}`;
      getCurrentUser();
    } else {
      setLoading(false);
    }
  }, []);

  const getCurrentUser = async () => {
    try {
      const response = await api.get('/auth/me');
      setUser(response.data.user);
    } catch (error) {
      localStorage.removeItem('token');
      delete api.defaults.headers.common['Authorization'];
    } finally {
      setLoading(false);
    }
  };

  const login = async (email, password) => {
    try {
      const response = await api.post('/auth/login', { email, password });
      const { token, user } = response.data;
      
      localStorage.setItem('token', token);
      api.defaults.headers.common['Authorization'] = `Bearer ${token}`;
      setUser(user);
      
      toast.success('Welcome back!');
      return { success: true };
    } catch (error) {
      const message = error.response?.data?.error || 'Login failed';
      toast.error(message);
      return { success: false, error: message };
    }
  };

  const register = async (username, email, password) => {
    try {
      const response = await api.post('/auth/register', { username, email, password });
      const { token, user } = response.data;
      
      localStorage.setItem('token', token);
      api.defaults.headers.common['Authorization'] = `Bearer ${token}`;
      setUser(user);
      
      toast.success('Account created successfully!');
      return { success: true };
    } catch (error) {
      const message = error.response?.data?.error || 'Registration failed';
      toast.error(message);
      return { success: false, error: message };
    }
  };

  const logout = () => {
    localStorage.removeItem('token');
    delete api.defaults.headers.common['Authorization'];
    setUser(null);
    toast.success('Logged out successfully');
  };

  const updateProfile = async (updates) => {
    try {
      const response = await api.put('/auth/profile', updates);
      setUser(response.data.user);
      toast.success('Profile updated successfully');
      return { success: true };
    } catch (error) {
      const message = error.response?.data?.error || 'Update failed';
      toast.error(message);
      return { success: false, error: message };
    }
  };

  const value = {
    user,
    loading,
    login,
    register,
    logout,
    updateProfile
  };

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