<?php

/**
 * This file is part of CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace CodeIgniter\Config;

use CodeIgniter\Autoloader\Autoloader;
use CodeIgniter\Autoloader\FileLocator;
use CodeIgniter\Cache\CacheInterface;
use CodeIgniter\CLI\Commands;
use CodeIgniter\CodeIgniter;
use CodeIgniter\Database\ConnectionInterface;
use CodeIgniter\Database\MigrationRunner;
use CodeIgniter\Debug\Exceptions;
use CodeIgniter\Debug\Iterator;
use CodeIgniter\Debug\Timer;
use CodeIgniter\Debug\Toolbar;
use CodeIgniter\Email\Email;
use CodeIgniter\Encryption\EncrypterInterface;
use CodeIgniter\Filters\Filters;
use CodeIgniter\Format\Format;
use CodeIgniter\Honeypot\Honeypot;
use CodeIgniter\HTTP\CLIRequest;
use CodeIgniter\HTTP\CURLRequest;
use CodeIgniter\HTTP\IncomingRequest;
use CodeIgniter\HTTP\Negotiate;
use CodeIgniter\HTTP\RedirectResponse;
use CodeIgniter\HTTP\Request;
use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\Response;
use CodeIgniter\HTTP\ResponseInterface;
use CodeIgniter\HTTP\URI;
use CodeIgniter\Images\Handlers\BaseHandler;
use CodeIgniter\Language\Language;
use CodeIgniter\Log\Logger;
use CodeIgniter\Pager\Pager;
use CodeIgniter\Router\RouteCollection;
use CodeIgniter\Router\RouteCollectionInterface;
use CodeIgniter\Router\Router;
use CodeIgniter\Security\Security;
use CodeIgniter\Session\Session;
use CodeIgniter\Throttle\Throttler;
use CodeIgniter\Typography\Typography;
use CodeIgniter\Validation\Validation;
use CodeIgniter\View\Cell;
use CodeIgniter\View\Parser;
use CodeIgniter\View\RendererInterface;
use CodeIgniter\View\View;
use Config\App;
use Config\Autoload;
use Config\Cache;
use Config\Encryption;
use Config\Exceptions as ConfigExceptions;
use Config\Filters as ConfigFilters;
use Config\Format as ConfigFormat;
use Config\Honeypot as ConfigHoneyPot;
use Config\Images;
use Config\Migrations;
use Config\Modules;
use Config\Pager as ConfigPager;
use Config\Services as AppServices;
use Config\Toolbar as ConfigToolbar;
use Config\Validation as ConfigValidation;
use Config\View as ConfigView;

/**
 * Services Configuration file.
 *
 * Services are simply other classes/libraries that the system uses
 * to do its job. This is used by CodeIgniter to allow the core of the
 * framework to be swapped out easily without affecting the usage within
 * the rest of your application.
 *
 * This is used in place of a Dependency Injection container primarily
 * due to its simplicity, which allows a better long-term maintenance
 * of the applications built on top of CodeIgniter. A bonus side-effect
 * is that IDEs are able to determine what class you are calling
 * whereas with DI Containers there usually isn't a way for them to do this.
 *
 * Warning: To allow overrides by service providers do not use static calls,
 * instead call out to \Config\Services (imported as AppServices).
 *
 * @see http://blog.ircmaxell.com/2015/11/simple-easy-risk-and-change.html
 * @see http://www.infoq.com/presentations/Simple-Made-Easy
 *
 * @method static CacheInterface cache(Cache $config = null, $getShared = true)
 * @method static CLIRequest clirequest(App $config = null, $getShared = true)
 * @method static CodeIgniter codeigniter(App $config = null, $getShared = true)
 * @method static Commands commands($getShared = true)
 * @method static CURLRequest curlrequest($options = [], ResponseInterface $response = null, App $config = null, $getShared = true)
 * @method static Email email($config = null, $getShared = true)
 * @method static EncrypterInterface encrypter(Encryption $config = null, $getShared = false)
 * @method static Exceptions exceptions(ConfigExceptions $config = null, IncomingRequest $request = null, Response $response = null, $getShared = true)
 * @method static Filters filters(ConfigFilters $config = null, $getShared = true)
 * @method static Format format(ConfigFormat $config = null, $getShared = true)
 * @method static Honeypot honeypot(ConfigHoneyPot $config = null, $getShared = true)
 * @method static BaseHandler image($handler = null, Images $config = null, $getShared = true)
 * @method static Iterator iterator($getShared = true)
 * @method static Language language($locale = null, $getShared = true)
 * @method static Logger logger($getShared = true)
 * @method static MigrationRunner migrations(Migrations $config = null, ConnectionInterface $db = null, $getShared = true)
 * @method static Negotiate negotiator(RequestInterface $request = null, $getShared = true)
 * @method static Pager pager(ConfigPager $config = null, RendererInterface $view = null, $getShared = true)
 * @method static Parser parser($viewPath = null, ConfigView $config = null, $getShared = true)
 * @method static RedirectResponse redirectresponse(App $config = null, $getShared = true)
 * @method static View renderer($viewPath = null, ConfigView $config = null, $getShared = true)
 * @method static IncomingRequest request(App $config = null, $getShared = true)
 * @method static Response response(App $config = null, $getShared = true)
 * @method static Router router(RouteCollectionInterface $routes = null, Request $request = null, $getShared = true)
 * @method static RouteCollection routes($getShared = true)
 * @method static Security security(App $config = null, $getShared = true)
 * @method static Session session(App $config = null, $getShared = true)
 * @method static Throttler throttler($getShared = true)
 * @method static Timer timer($getShared = true)
 * @method static Toolbar toolbar(ConfigToolbar $config = null, $getShared = true)
 * @method static Typography typography($getShared = true)
 * @method static URI uri($uri = null, $getShared = true)
 * @method static Validation validation(ConfigValidation $config = null, $getShared = true)
 * @method static Cell viewcell($getShared = true)
 */
class BaseService
{
    /**
     * Cache for instance of any services that
     * have been requested as a "shared" instance.
     * Keys should be lowercase service names.
     *
     * @var array
     */
    protected static $instances = [];

    /**
     * Mock objects for testing which are returned if exist.
     *
     * @var array
     */
    protected static $mocks = [];

    /**
     * Have we already discovered other Services?
     *
     * @var bool
     */
    protected static $discovered = false;

    /**
     * A cache of other service classes we've found.
     *
     * @var array
     */
    protected static $services = [];

    /**
     * A cache of the names of services classes found.
     *
     * @var array<string>
     */
    private static $serviceNames = [];

    /**
     * Returns a shared instance of any of the class' services.
     *
     * $key must be a name matching a service.
     *
     * @param mixed ...$params
     *
     * @return mixed
     */
    protected static function getSharedInstance(string $key, ...$params)
    {
        $key = strtolower($key);

        // Returns mock if exists
        if (isset(static::$mocks[$key])) {
            return static::$mocks[$key];
        }

        if (! isset(static::$instances[$key])) {
            // Make sure $getShared is false
            $params[] = false;

            static::$instances[$key] = AppServices::$key(...$params);
        }

        return static::$instances[$key];
    }

    /**
     * The Autoloader class is the central class that handles our
     * spl_autoload_register method, and helper methods.
     *
     * @return Autoloader
     */
    public static function autoloader(bool $getShared = true)
    {
        if ($getShared) {
            if (empty(static::$instances['autoloader'])) {
                static::$instances['autoloader'] = new Autoloader();
            }

            return static::$instances['autoloader'];
        }

        return new Autoloader();
    }

    /**
     * The file locator provides utility methods for looking for non-classes
     * within namespaced folders, as well as convenience methods for
     * loading 'helpers', and 'libraries'.
     *
     * @return FileLocator
     */
    public static function locator(bool $getShared = true)
    {
        if ($getShared) {
            if (empty(static::$instances['locator'])) {
                static::$instances['locator'] = new FileLocator(static::autoloader());
            }

            return static::$mocks['locator'] ?? static::$instances['locator'];
        }

        return new FileLocator(static::autoloader());
    }

    /**
     * Provides the ability to perform case-insensitive calling of service
     * names.
     *
     * @return mixed
     */
    public static function __callStatic(string $name, array $arguments)
    {
        $service = static::serviceExists($name);

        if ($service === null) {
            return null;
        }

        return $service::$name(...$arguments);
    }

    /**
     * Check if the requested service is defined and return the declaring
     * class. Return null if not found.
     */
    public static function serviceExists(string $name): ?string
    {
        static::buildServicesCache();
        $services = array_merge(self::$serviceNames, [Services::class]);
        $name     = strtolower($name);

        foreach ($services as $service) {
            if (method_exists($service, $name)) {
                return $service;
            }
        }

        return null;
    }

    /**
     * Reset shared instances and mocks for testing.
     */
    public static function reset(bool $initAutoloader = false)
    {
        static::$mocks     = [];
        static::$instances = [];

        if ($initAutoloader) {
            static::autoloader()->initialize(new Autoload(), new Modules());
        }
    }

    /**
     * Resets any mock and shared instances for a single service.
     */
    public static function resetSingle(string $name)
    {
        unset(static::$mocks[$name], static::$instances[$name]);
    }

    /**
     * Inject mock object for testing.
     *
     * @param mixed $mock
     */
    public static function injectMock(string $name, $mock)
    {
        static::$mocks[strtolower($name)] = $mock;
    }

    /**
     * Will scan all psr4 namespaces registered with system to look
     * for new Config\Services files. Caches a copy of each one, then
     * looks for the service method in each, returning an instance of
     * the service, if available.
     *
     * @return mixed
     *
     * @deprecated
     *
     * @codeCoverageIgnore
     */
    protected static function discoverServices(string $name, array $arguments)
    {
        if (! static::$discovered) {
            $config = config('Modules');

            if ($config->shouldDiscover('services')) {
                $locator = static::locator();
                $files   = $locator->search('Config/Services');

                if (empty($files)) {
                    // no files at all found - this would be really, really bad
                    return null;
                }

                // Get instances of all service classes and cache them locally.
                foreach ($files as $file) {
                    $classname = $locator->getClassname($file);

                    if (! in_array($classname, ['CodeIgniter\\Config\\Services'], true)) {
                        static::$services[] = new $classname();
                    }
                }
            }

            static::$discovered = true;
        }

        if (! static::$services) {
            // we found stuff, but no services - this would be really bad
            return null;
        }

        // Try to find the desired service method
        foreach (static::$services as $class) {
            if (method_exists($class, $name)) {
                return $class::$name(...$arguments);
            }
        }

        return null;
    }

    protected static function buildServicesCache(): void
    {
        if (! static::$discovered) {
            $config = config('Modules');

            if ($config->shouldDiscover('services')) {
                $locator = static::locator();
                $files   = $locator->search('Config/Services');

                // Get instances of all service classes and cache them locally.
                foreach ($files as $file) {
                    $classname = $locator->getClassname($file);

                    if ($classname !== 'CodeIgniter\\Config\\Services') {
                        self::$serviceNames[] = $classname;
                        static::$services[]   = new $classname();
                    }
                }
            }

            static::$discovered = true;
        }
    }
}
