import axios from 'axios';
import { tokenStorage } from '@/lib/utils/tokenStorage';

const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000';

export const apiClient = axios.create({
  baseURL: API_BASE_URL,
  headers: {
    'Content-Type': 'application/json',
  },
  withCredentials: true,
});

// Request interceptor to add auth token
apiClient.interceptors.request.use(
  (config) => {
    const token = tokenStorage.getAccessToken();
    if (token) {
      config.headers.Authorization = `Bearer ${token}`;
    }
    return config;
  },
  (error) => {
    return Promise.reject(error);
  }
);

// Response interceptor to handle token refresh
apiClient.interceptors.response.use(
  (response) => response,
  async (error) => {
    const originalRequest = error.config;

    // Only handle token refresh on client side
    if (typeof window === 'undefined') {
      return Promise.reject(error);
    }

    // If error is 401 and we haven't tried to refresh yet
    if (error.response?.status === 401 && !originalRequest._retry) {
      originalRequest._retry = true;

      try {
        const refreshToken = tokenStorage.getRefreshToken();
        if (!refreshToken) {
          throw new Error('No refresh token');
        }

        const response = await axios.post(
          `${API_BASE_URL}/api/v1/auth/refresh`,
          { refreshToken },
          {
            headers: { 'Content-Type': 'application/json' },
            withCredentials: true
          }
        );

        // Handle different response structures
        let newAccessToken;
        let newRefreshToken;

        if (response.data?.data?.tokens?.accessToken) {
          newAccessToken = response.data.data.tokens.accessToken;
          newRefreshToken = response.data.data.tokens.refreshToken;
        } else if (response.data?.tokens?.accessToken) {
          newAccessToken = response.data.tokens.accessToken;
          newRefreshToken = response.data.tokens.refreshToken;
        } else if (response.data?.accessToken) {
          newAccessToken = response.data.accessToken;
          newRefreshToken = response.data.refreshToken;
        } else {
          throw new Error('Invalid token refresh response');
        }

        // Update tokens in storage
        tokenStorage.setAccessToken(newAccessToken);
        if (newRefreshToken) {
          tokenStorage.setRefreshToken(newRefreshToken);
        }

        // Retry original request with new token
        originalRequest.headers.Authorization = `Bearer ${newAccessToken}`;
        return apiClient(originalRequest);
      } catch (refreshError) {
        console.error('Token refresh failed:', refreshError);
        // Refresh failed, clear tokens and redirect to login
        tokenStorage.clearTokens();

        // Avoid redirect loop - only redirect if not already on login page
        if (!window.location.pathname.includes('/login')) {
          window.location.href = '/login';
        }
        return Promise.reject(refreshError);
      }
    }

    return Promise.reject(error);
  }
);

export default apiClient;