Building a Generic API Wrapper Class (PHP)

<?php

class ApiClient {
    private $baseUrl;
    private $headers = [];
    private $lastError = null;

    public function __construct($baseUrl, $defaultHeaders = []) {
        $this->baseUrl = rtrim($baseUrl, '/');
        $this->headers = array_merge([
            'Content-Type: application/json',
            'Accept: application/json'
        ], $defaultHeaders);
    }

    public function setHeader($name, $value) {
        // Remove existing header with the same name before adding
        $this->headers = array_filter($this->headers, function($header) use ($name) {
            return strpos($header, $name . ':') !== 0;
        });
        $this->headers[] = "$name: $value";
        return $this;
    }

    public function setAuthToken($token) {
        return $this->setHeader('Authorization', 'Bearer ' . $token);
    }

    private function makeRequest($method, $path, $data = null) {
        $url = $this->baseUrl . '/' . ltrim($path, '/');
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $this->headers);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30); // 30 second timeout

        switch (strtoupper($method)) {
            case 'POST':
                curl_setopt($ch, CURLOPT_POST, true);
                if ($data !== null) {
                    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
                }
                break;
            case 'PUT':
                curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
                if ($data !== null) {
                    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
                }
                break;
            case 'DELETE':
                curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE');
                break;
            // GET is default
        }

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($response === false) {
            $this->lastError = "cURL Error: " . $error;
            return false;
        }

        $decodedResponse = json_decode($response, true);
        if (json_last_error() !== JSON_ERROR_NONE) {
            $this->lastError = "JSON Decode Error: " . json_last_error_msg() . " - Raw: " . $response;
            return false;
        }

        if ($httpCode >= 400) {
            $this->lastError = "API Error (HTTP $httpCode): " . ($decodedResponse['message'] ?? 'Unknown error');
            return false;
        }

        $this->lastError = null; // Clear error on success
        return $decodedResponse;
    }

    public function get($path) {
        return $this->makeRequest('GET', $path);
    }

    public function post($path, $data) {
        return $this->makeRequest('POST', $path, $data);
    }

    public function put($path, $data) {
        return $this->makeRequest('PUT', $path, $data);
    }

    public function delete($path) {
        return $this->makeRequest('DELETE', $path);
    }

    public function getLastError() {
        return $this->lastError;
    }
}

// Example Usage:
/*
// require_once 'ApiClient.php'; // If in a separate file

$apiClient = new ApiClient('https://jsonplaceholder.typicode.com');

// Set a custom header or auth token
$apiClient->setAuthToken('YOUR_SUPER_SECRET_TOKEN');

// GET request
$posts = $apiClient->get('/posts');
if ($posts) {
    // print_r($posts);
    // echo "Fetched " . count($posts) . " posts.
";
} else {
    // echo "Error fetching posts: " . $apiClient->getLastError() . "
";
}

// POST request
$newPost = [
    'title' => 'foo',
    'body' => 'bar',
    'userId' => 1,
];
$createdPost = $apiClient->post('/posts', $newPost);
if ($createdPost) {
    // echo "Created post with ID: " . $createdPost['id'] . "
";
    // print_r($createdPost);
} else {
    // echo "Error creating post: " . $apiClient->getLastError() . "
";
}
*/