import axios from 'axios';

// Einheitliche Basis-URL:
// - immer relativ zur aktuellen Origin
// - kein absoluter http/https-Host → verhindert Mixed-Content-Probleme
axios.defaults.baseURL = '/api';
console.log('Axios baseURL:', axios.defaults.baseURL);

function clearStoredLogin() {
  localStorage.removeItem('isLoggedIn');
  localStorage.removeItem('user');
  localStorage.removeItem('token');
  delete axios.defaults.headers.common.Authorization;
}

function getTokenPayload(token) {
  try {
    const payload = token.split('.')[1];
    const normalized = payload.replace(/-/g, '+').replace(/_/g, '/');
    const padded = normalized.padEnd(normalized.length + (4 - normalized.length % 4) % 4, '=');
    return JSON.parse(atob(padded));
  } catch (error) {
    return null;
  }
}

function isTokenUsable(token) {
  if (!token || token === 'undefined' || token === 'null') {
    return false;
  }
  const payload = getTokenPayload(token);
  if (!payload || !payload.exp) {
    return true;
  }
  return payload.exp * 1000 > Date.now();
}

axios.interceptors.request.use(
  config => {
    const token = localStorage.getItem('token');
    config.headers = config.headers || {};
    if (token) {
      if (isTokenUsable(token)) {
        config.headers.Authorization = `Bearer ${token}`;
      } else {
        clearStoredLogin();
        delete config.headers.Authorization;
      }
    }
    return config;
  },
  error => {
    return Promise.reject(error);
  }
);

axios.interceptors.response.use(
  response => {
    return response;
  },
  error => {
    const requestUrl = error.config?.url || '';
    const isLoginRequest = requestUrl.includes('/auth/login');
    const isLogoutRequest = requestUrl.includes('/auth/logout');
    const hasStoredToken = isTokenUsable(localStorage.getItem('token'));
    const hadAuthHeader = !!error.config?.headers?.Authorization;

    if (
      error.response &&
      error.response.status === 401 &&
      !isLoginRequest &&
      !isLogoutRequest &&
      (hasStoredToken || hadAuthHeader)
    ) {
      clearStoredLogin();
      if (window.location.pathname !== '/auth/login') {
        window.location.replace('/auth/login');
      }
    }
    return Promise.reject(error);
  }
);

export default axios;