<?php
// composer.json for a hypothetical PHP API Client Library
// This file defines the library's dependencies and autoloading rules.
{
    "name": "vendor/my-api-client",
    "description": "A robust PHP client for the My API service.",
    "type": "library",
    "keywords": ["API", "Client", "PHP", "My API"],
    "license": "MIT",
    "authors": [
        {
            "name": "Your Name",
            "email": "your.email@example.com"
        }
    ],
    "require": {
        "php": ">=7.4",
        "guzzlehttp/guzzle": "^7.0",
        "symfony/serializer": "^5.0 || ^6.0"
    },
    "require-dev": {
        "phpunit/phpunit": "^9.5",
        "phpstan/phpstan": "^1.0"
    },
    "autoload": {
        "psr-4": {
            "Vendor\\MyApiClient\\": "src/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "Vendor\\MyApiClient\\Tests\\": "tests/"
        }
    },
    "config": {
        "sort-packages": true
    },
    "minimum-stability": "stable",
    "prefer-stable": true
}

<?php
// Example of initial setup for a PHP API client.
// This snippet demonstrates how to instantiate the client and configure it.

require 'vendor/autoload.php';

use Vendor\MyApiClient\Client;
use Vendor\MyApiClient\Configuration;

// 1. Define configuration settings
// We recommend using environment variables or a configuration file
// for sensitive data like API keys.
$apiKey = getenv('MY_API_KEY') ?: 'your_actual_api_key'; // Replace with your actual API key or env var
$baseUrl = 'https://api.example.com/v1'; // Base URL for the API

// 2. Create a Configuration object
$config = new Configuration([
    'apiKey' => $apiKey,
    'baseUrl' => $baseUrl,
    'timeout' => 30 // Optional: Set a request timeout in seconds
]);

// 3. Instantiate the API client
try {
    $client = new Client($config);
    
    echo "API Client successfully initialized.\n";
    // You can now proceed to make API requests using the $client object.
    // e.g., $client->users()->get(1);

} catch (\InvalidArgumentException $e) {
    // Handle invalid configuration, e.g., missing API key
    error_log("Configuration error: " . $e->getMessage());
    die("Initialization failed due to configuration issues.");
} catch (\Exception $e) {
    // Catch other potential initialization errors
    error_log("An unexpected error occurred during client initialization: " . $e->getMessage());
    die("Initialization failed.");
}

// Further examples would demonstrate how to use specific API methods.

<?php
// This example builds upon the client initialization from the previous step.
// Ensure 'vendor/autoload.php' is included and $client is instantiated.

require 'vendor/autoload.php';

// Assuming $client is already initialized from 'Architecting Clarity' section
use Vendor\MyApiClient\Client;
use Vendor\MyApiClient\Configuration;
use GuzzleHttp\Exception\ClientException; // For HTTP 4xx errors
use GuzzleHttp\Exception\ServerException; // For HTTP 5xx errors
use GuzzleHttp\Exception\ConnectException; // For network errors

// Placeholder for an initialized client (in a real scenario, this comes from previous setup)
$config = new Configuration(['apiKey' => 'YOUR_API_KEY', 'baseUrl' => 'https://api.example.com/v1']);
$client = new Client($config); 

echo "\n--- Making a GET request ---\n";

try {
    // Example: Fetch a user by ID
    $userId = 123;
    $response = $client->users()->get($userId);

    // Accessing response data
    echo "User fetched successfully!\n";
    echo "User Name: " . $response['name'] . "\n";
    echo "User Email: " . $response['email'] . "\n";
    
} catch (ClientException $e) {
    // Handles 4xx HTTP errors (e.g., 404 Not Found, 401 Unauthorized)
    $statusCode = $e->getResponse()->getStatusCode();
    $responseBody = $e->getResponse()->getBody()->getContents();
    error_log("Client error ($statusCode): " . $responseBody);
    echo "Error: " . json_decode($responseBody)->message . "\n";
    
} catch (ServerException $e) {
    // Handles 5xx HTTP errors (e.g., 500 Internal Server Error)
    $statusCode = $e->getResponse()->getStatusCode();
    $responseBody = $e->getResponse()->getBody()->getContents();
    error_log("Server error ($statusCode): " . $responseBody);
    echo "Server Error: An issue occurred on the API server.\n";
    
} catch (ConnectException $e) {
    // Handles network errors (e.g., host unreachable)
    error_log("Connection error: " . $e->getMessage());
    echo "Network Error: Could not connect to the API.\n";
    
} catch (\Exception $e) {
    // Catch any other unexpected errors
    error_log("An unexpected error occurred: " . $e->getMessage());
    echo "An unexpected error occurred.\n";
}

echo "\n--- Making a POST request ---\n";

try {
    // Example: Create a new user
    $newUserPayload = [
        'name' => 'Jane Doe',
        'email' => 'jane.doe@example.com'
    ];
    $response = $client->users()->create($newUserPayload);

    echo "New user created successfully!\n";
    echo "New User ID: " . $response['id'] . "\n";

} catch (ClientException $e) {
    $statusCode = $e->getResponse()->getStatusCode();
    $responseBody = $e->getResponse()->getBody()->getContents();
    error_log("Client error ($statusCode) during user creation: " . $responseBody);
    echo "Error creating user: " . json_decode($responseBody)->message . "\n";
    
} catch (\Exception $e) {
    error_log("An unexpected error occurred during user creation: " . $e->getMessage());
    echo "An unexpected error occurred during user creation.\n";
}

<?php
// tests/Unit/MyApiClientTest.php
// A basic PHPUnit test file structure for a PHP API client library.

namespace Vendor\MyApiClient\Tests\Unit;

use PHPUnit\Framework\TestCase;
use Vendor\MyApiClient\Client;
use Vendor\MyApiClient\Configuration;

class MyApiClientTest extends TestCase
{
    private ?Client $client;

    protected function setUp(): void
    {
        parent::setUp();
        // Initialize client with mock data or test configuration
        // In a real scenario, consider using a testing API endpoint or mocking HTTP requests.
        $config = new Configuration([
            'apiKey' => 'TEST_API_KEY',
            'baseUrl' => 'http://localhost:8000/mock-api/v1' // Use a mock server or specific test endpoint
        ]);
        $this->client = new Client($config);
    }

    protected function tearDown(): void
    {
        $this->client = null;
        parent::tearDown();
    }

    public function testGetUsersReturnsArray(): void
    {
        // Simulate an API call and assert its outcome
        // For actual API calls, use mocking frameworks like Guzzle Mock Handler
        // This example assumes a simple mock response for illustration.
        $mockResponse = [
            ['id' => 1, 'name' => 'Test User 1'],
            ['id' => 2, 'name' => 'Test User 2']
        ];
        // In a real test, $this->client->users()->getAll() would return this mocked response
        $result = $mockResponse; 

        $this->assertIsArray($result);
        $this->assertCount(2, $result);
        $this->assertEquals('Test User 1', $result[0]['name']);
    }

    public function testCreateUserReturnsNewId(): void
    {
        $newUserData = ['name' => 'New Test User'];
        $mockCreatedResponse = ['id' => 3, 'name' => 'New Test User'];
        // In a real test, $this->client->users()->create($newUserData) would return this mocked response
        $result = $mockCreatedResponse;

        $this->assertIsArray($result);
        $this->assertArrayHasKey('id', $result);
        $this->assertEquals(3, $result['id']);
    }

    // Add more test methods for different API endpoints and scenarios (e.g., error cases)
}