BaseStrategy.php

<?php

/**
 * This file is part of response-cache, a Matchory library.
 *
 * @author Moritz Friedrich <moritz@matchory.com>
 */

declare(strict_types=1);

namespace Matchory\ResponseCache\Support;

use Illuminate\Auth\AuthManager;
use Illuminate\Http\Request;
use Matchory\ResponseCache\Contracts\CacheStrategy;
use Symfony\Component\HttpFoundation\Response;

use function md5;

/**
 * Base Strategy
 *
 * @bundle Matchory\ResponseCache
 */
class BaseStrategy implements CacheStrategy
{
    public function __construct(protected readonly AuthManager $auth) {}

    /**
     * {@inheritDoc}
     */
    public function key(Request $request): string
    {
        $identifier = $this->extractRequestIdentifier($request);
        $suffix = $this->buildSuffix($request);

        return $this->hash($identifier . $suffix);
    }

    /**
     * {@inheritDoc}
     */
    public function shouldCache(Request $request, Response $response): bool
    {
        if (! $this->isMethodCachable($request)) {
            return false;
        }

        return $this->isSuccessful($response);
    }

    /**
     * {@inheritDoc}
     */
    public function tags(Request $request, Response|null $response = null): array
    {
        return [];
    }

    /**
     * Retrieves a suffix to append to the key before it is hashed. This allows
     * to constrain the cache key to the authenticated user, for example.
     *
     * @noinspection PhpUnusedParameterInspection
     */
    protected function buildSuffix(Request $request): string
    {
        return $this->auth->check()
            ? (string) $this->auth->id()
            : '';
    }

    /**
     * Extracts a unique identifier from a request. The default implementation
     * will use the full URL as provided by Laravel.
     *
     * @param  Request  $request  Current request instance.
     * @return string Unique request identifier.
     */
    protected function extractRequestIdentifier(Request $request): string
    {
        return $request->method() . $request->fullUrl();
    }

    /**
     * Hashes the cache key. The default implementation will return an MD5 hash
     * of the given key.
     */
    protected function hash(string $key): string
    {
        return md5($key);
    }

    /**
     * Checks whether the request method if a request is safe to cache.
     *
     * @param  Request  $request  Request instance.
     * @return bool Whether the method is safe to cache.
     */
    protected function isMethodCachable(Request $request): bool
    {
        return $request->isMethodCacheable();
    }

    /**
     * Checks whether a response is successful. The default implementation will
     * succeed if the status code is in the 2xx-3xx range.
     *
     * @param  Response  $response  Response instance.
     * @return bool Whether the response is successful
     */
    protected function isSuccessful(Response $response): bool
    {
        return $response->isSuccessful() || $response->isRedirection();
    }
}