Authenticating API Requests with Bearer Tokens

async function callAuthenticatedApi(url, token, method = 'GET', data = null) {
  const headers = {
    'Authorization': `Bearer ${token}` // Include the Bearer token
  };

  const fetchOptions = {
    method: method,
    headers: headers
  };

  if (data && (method === 'POST' || method === 'PUT' || method === 'PATCH')) {
    headers['Content-Type'] = 'application/json';
    fetchOptions.body = JSON.stringify(data);
  }

  try {
    const response = await fetch(url, fetchOptions);

    if (response.status === 401 || response.status === 403) {
      console.warn('Authentication failed or unauthorized access.');
      // Potentially redirect to login or refresh token
    }

    if (!response.ok) {
      const errorBody = await response.text();
      throw new Error(`API error! Status: ${response.status}, Message: ${errorBody}`);
    }

    const jsonResponse = await response.json();
    return jsonResponse;
  } catch (error) {
    console.error('Authenticated API call failed:', error);
    throw error; // Re-throw for caller handling
  }
}

// Example usage:
// const userToken = 'YOUR_JWT_OR_OAUTH_TOKEN'; // Get this from login/session
// callAuthenticatedApi('https://api.example.com/profile', userToken)
//   .then(profileData => console.log('User Profile:', profileData))
//   .catch(err => console.error('Failed to get profile:', err));

// const newPost = { title: 'Auth Post', content: 'Secured content' };
// callAuthenticatedApi('https://api.example.com/posts', userToken, 'POST', newPost)
//   .then(createdPost => console.log('Post created:', createdPost))
//   .catch(err => console.error('Failed to create post:', err));