proposal-system/web/src/lib/api/client.ts

import axios from 'axios';
import { API_URL, STORAGE_KEY_TOKEN } from '../../constants';

const apiClient = axios.create({
  baseURL: API_URL,
  headers: {
    'Content-Type': 'application/json',
    Accept: 'application/json',
  },
});

apiClient.interceptors.request.use(
  (config) => {
    const tokenData = window.localStorage.getItem(STORAGE_KEY_TOKEN);
    if (tokenData) {
      try {
        const parsed = JSON.parse(tokenData);
        if (parsed?.token) {
          config.headers.Authorization = `Bearer ${parsed.token}`;
        }
      } catch {
        // Invalid token data
      }
    }
    return config;
  },
  (error) => Promise.reject(error)
);

apiClient.interceptors.response.use(
  (response) => response,
  (error) => {
    if (error.response) {
      const { status, data } = error.response;

      if (status === 401) {
        window.localStorage.removeItem(STORAGE_KEY_TOKEN);
        window.location.href = '/login';
        return Promise.reject(new Error('Session expired. Please log in again.'));
      }

      if (status === 403) {
        return Promise.reject(new Error('You do not have permission to perform this action.'));
      }

      if (status === 404) {
        return Promise.reject(new Error('The requested resource was not found.'));
      }

      const message = data?.detail || data?.title || data?.message || 'An error occurred';
      return Promise.reject(new Error(message));
    }

    if (error.request) {
      return Promise.reject(new Error('No response from server. Please check your connection.'));
    }

    return Promise.reject(error);
  }
);

export default apiClient;