Centralized Axios API Client with Interceptors

import axios from 'axios';

// Create a custom Axios instance
const apiClient = axios.create({
  baseURL: 'https://api.example.com/v1',
  timeout: 10000, // Request timeout in ms
  headers: {
    'Content-Type': 'application/json',
  },
});

// Request Interceptor: Add authorization token
apiClient.interceptors.request.use(
  config => {
    const token = localStorage.getItem('authToken'); // Or from a state management store
    if (token) {
      config.headers.Authorization = `Bearer ${token}`;
    }
    // Optional: Log request details
    // console.log('Request:', config.method?.toUpperCase(), config.url, config.data || config.params);
    return config;
  },
  error => {
    // Handle request errors (e.g., network issues before sending)
    console.error('Request error:', error);
    return Promise.reject(error);
  }
);

// Response Interceptor: Handle global errors, refresh tokens, etc.
apiClient.interceptors.response.use(
  response => {
    // Optional: Log response data
    // console.log('Response:', response.config.url, response.status, response.data);
    return response;
  },
  async error => {
    const originalRequest = error.config;

    // Example: Handle 401 Unauthorized globally (e.g., for token refresh)
    if (error.response?.status === 401 && !originalRequest._retry) {
      originalRequest._retry = true;
      // Implement token refresh logic here
      // try {
      //   const refreshToken = localStorage.getItem('refreshToken');
      //   const { data } = await axios.post('/auth/refresh-token', { refreshToken });
      //   localStorage.setItem('authToken', data.newToken);
      //   apiClient.defaults.headers.common['Authorization'] = `Bearer ${data.newToken}`;
      //   return apiClient(originalRequest); // Retry the original request with new token
      // } catch (refreshError) {
      //   console.error('Token refresh failed:', refreshError);
      //   // Redirect to login or clear auth data
      //   // window.location.href = '/login';
      //   return Promise.reject(refreshError);
      // }
      console.warn('401 Unauthorized - token refresh logic would go here.');
    }

    // Handle other errors
    console.error('Response error:', error.response?.status, error.response?.data || error.message);
    return Promise.reject(error);
  }
);

export default apiClient;

// Example Usage (in another file):
// import apiClient from './apiClient';
//
// async function getUserData() {
//   try {
//     const response = await apiClient.get('/users/me');
//     console.log('User data:', response.data);
//   } catch (error) {
//     console.error('Failed to get user data:', error);
//   }
// }
//
// async function createPost(postData) {
//   try {
//     const response = await apiClient.post('/posts', postData);
//     console.log('Post created:', response.data);
//   } catch (error) {
//     console.error('Failed to create post:', error);
//   }
// }