import type { 
  LoginRequest, 
  LoginResponse, 
  RefreshTokenResponse, 
  AuthError,
  UserData 
} from '@/types/auth';

import { API_CONFIG, AUTH_ENDPOINTS, DEFAULT_HEADERS, buildApiUrl } from '@/lib/config';
import { debugRequest } from '@/lib/debug-utils';
import { ENV_CONFIG } from '@/lib/env-config';

/**
 * Classe de erro customizada para autenticação
 */
export class AuthenticationError extends Error {
  constructor(
    message: string,
    public code: string,
    public details?: any
  ) {
    super(message);
    this.name = 'AuthenticationError';
  }
}

/**
 * Headers para requisições autenticadas (COM Bearer token)
 */
function getAuthHeaders(token: string): Record<string, string> {
  return {
    "Content-Type": "application/json",
    "Accept": "application/json",
    "apikey": ENV_CONFIG.SUPABASE_ANON_KEY,
    "Authorization": `Bearer ${token}`,
  };
}

/**
 * Headers APENAS para login (SEM Authorization Bearer)
 */
function getLoginHeaders(): Record<string, string> {
  return {
    "Content-Type": "application/json",
    "Accept": "application/json",
    "apikey": ENV_CONFIG.SUPABASE_ANON_KEY,
  };
}

/**
 * Utilitário para processar resposta da API
 */
async function processResponse<T>(response: Response): Promise<T> {
  console.log(`[AUTH] Response status: ${response.status} ${response.statusText}`);
  
  let data: any = null;
  
  try {
    const text = await response.text();
    if (text) {
      data = JSON.parse(text);
    }
  } catch (error) {
    console.log('[AUTH] Response sem JSON ou vazia (normal para alguns endpoints)');
  }

  if (!response.ok) {
    const errorMessage = data?.message || data?.error || response.statusText || 'Erro na autenticação';
    const errorCode = data?.code || String(response.status);
    
    console.error('[AUTH ERROR]', {
      url: response.url,
      status: response.status,
      data,
    });

    throw new AuthenticationError(errorMessage, errorCode, data);
  }

  console.log('[AUTH] Response data:', data);
  return data as T;
}

/**
 * Serviço para fazer login e obter token JWT
 * POST /auth/v1/token?grant_type=password
 */
export async function loginUser(
  email: string, 
  password: string
): Promise<LoginResponse> {
  const url = `${AUTH_ENDPOINTS.LOGIN}?grant_type=password`;
  const headers = getLoginHeaders();
  
  const body = JSON.stringify({ email, password });
  
  console.log('[AUTH] Login request:', { url, email });
  
  const response = await fetch(url, {
    method: 'POST',
    headers,
    body,
  });

  return processResponse<LoginResponse>(response);
}

/**
 * Serviço para fazer logout do usuário
 * POST /auth/v1/logout
 */
export async function logoutUser(token: string): Promise<void> {
  const url = AUTH_ENDPOINTS.LOGOUT;
  const headers = getAuthHeaders(token);
  
  console.log('[AUTH] Logout request');
  
  const response = await fetch(url, {
    method: 'POST',
    headers,
  });

  if (!response.ok && response.status !== 204) {
    await processResponse(response);
  }
}

/**
 * Serviço para renovar token JWT
 * POST /auth/v1/token?grant_type=refresh_token
 */
export async function refreshAuthToken(refreshToken: string): Promise<RefreshTokenResponse> {
  const url = `${AUTH_ENDPOINTS.LOGIN}?grant_type=refresh_token`;
  const headers = getLoginHeaders();
  
  const body = JSON.stringify({ refresh_token: refreshToken });
  
  console.log('[AUTH] Refresh token request');
  
  const response = await fetch(url, {
    method: 'POST',
    headers,
    body,
  });

  return processResponse<RefreshTokenResponse>(response);
}

/**
 * Serviço para obter dados do usuário atual
 * GET /auth/v1/user
 */
export async function getCurrentUser(token: string): Promise<UserData> {
  const url = AUTH_ENDPOINTS.USER;
  const headers = getAuthHeaders(token);
  
  console.log('[AUTH] Get current user request');
  
  const response = await fetch(url, {
    method: 'GET',
    headers,
  });

  return processResponse<UserData>(response);
}

/**
 * Utilitário para validar se um token está expirado
 */
export function isTokenExpired(expiryTimestamp: number): boolean {
  const now = Date.now();
  const expiry = expiryTimestamp * 1000; // Converter para milliseconds
  const buffer = 5 * 60 * 1000; // Buffer de 5 minutos
  
  return now >= (expiry - buffer);
}

/**
 * Utilitário para interceptar requests e adicionar token automaticamente
 */
export function createAuthenticatedFetch(getToken: () => string | null) {
  return async (url: string, options: RequestInit = {}): Promise<Response> => {
    const token = getToken();
    
    if (token) {
      const headers = {
        ...options.headers,
        ...getAuthHeaders(token),
      };
      
      options = {
        ...options,
        headers,
      };
    }

    return fetch(url, options);
  };
}