import React, { createContext, useContext, useState, useEffect } from 'react';
import { User, AuthContextType } from '../types';

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

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

interface AuthProviderProps {
  children: React.ReactNode;
}

export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
  const [user, setUser] = useState<User | null>(null);

  useEffect(() => {
    const token = localStorage.getItem('token');
    if (token) {
      // Verificar se o token ainda é válido
      fetch('/api/verify', {
        headers: {
          'Authorization': `Bearer ${token}`
        }
      })
      .then(response => response.json())
      .then(data => {
        if (data.valid) {
          setUser(data.user);
        } else {
          localStorage.removeItem('token');
        }
      })
      .catch(() => {
        localStorage.removeItem('token');
      });
    }
  }, []);

  const login = async (username: string, password: string): Promise<boolean> => {
    try {
      const response = await fetch('/api/login', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ username, password }),
      });

      if (response.ok) {
        const data = await response.json();
        localStorage.setItem('token', data.token);
        setUser(data.user);
        return true;
      }
      return false;
    } catch (error) {
      console.error('Erro no login:', error);
      return false;
    }
  };

  const logout = () => {
    localStorage.removeItem('token');
    setUser(null);
  };

  const value: AuthContextType = {
    user,
    login,
    logout,
    isAuthenticated: !!user,
  };

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