Super basic magic method for creating REST API clients in PHP

rest-client.php

<?php
use Requests;

/**
 * Instances of this class can be invoked with any of the HTTP request 
 * method names (get, post, put, delete, head, etc.), and doing so builds
 * and invokes a request using the Requests library.
 * @see https://github.com/rmccue/Requests
 */
abstract RestClient {

  protected $apiKey;
  
  protected $baseUrl;

  function __call($name, $args)
  {
    $method = strtolower($name);

    $headers = [];

    $data = null;

    $path = '';

    $options = [ 'auth' => [ $this->apiKey, '' ] ];

    $url = $this->baseUrl;

    if (!empty($args[0])) {
      $url .= '/' . ltrim($args[0], '/');
    }

    if (!empty($args[2])) {
      $headers = $args[2];
    }

    if (!empty($args[1])) {
      $data = $args[1];
    }

    if (!empty($args[3])) {
      $options = array_merge($options, $args[3]);
    }

    $args = [ $url, $headers ];

    if ($method === 'post' || $method === 'put') {
      $args[] = $data;
    } else if (!empty($data)) {
      $url .= '?' . http_build_query($data);
    }

    $args[] = $options;

    $response = call_user_func_array("Requests::{$method}", $args);

    if ($response->status_code >= 300) {
      if ($errorData = json_decode($response->body)) {
        $error = $errorData->error;
        if (is_array($error)) {
          $error = $error[0];
        }

        throw new \Exception($error, $response->status_code);
      } else {
        throw new \Exception($response->body, $response->status_code);
      }
    }
  
    return json_decode($response->body);
  }
 
}