michaelschiemer/src/Framework/Http/MiddlewareCircuitBreaker.php

<?php

declare(strict_types=1);

namespace App\Framework\Http;

use App\Framework\CircuitBreaker\CircuitBreaker;
use App\Framework\CircuitBreaker\CircuitBreakerConfig;
use App\Framework\CircuitBreaker\CircuitState;
use App\Framework\Core\ValueObjects\Duration;
use RuntimeException;
use Throwable;

/**
 * Circuit breaker for middlewares to prevent repeatedly failing middlewares from being executed
 *
 * This class is a wrapper around the CircuitBreaker module that provides middleware-specific functionality.
 */
final class MiddlewareCircuitBreaker
{
    /**
     * Default configuration for middleware circuit breakers
     */
    private CircuitBreakerConfig $defaultConfig;

    /**
     * @param CircuitBreaker $circuitBreaker The circuit breaker instance
     * @param int $failureThreshold Number of failures before opening the circuit
     * @param int $recoveryTimeoutSeconds Time in seconds to keep the circuit open
     */
    public function __construct(
        private readonly CircuitBreaker $circuitBreaker,
        int $failureThreshold = 5,
        int $recoveryTimeoutSeconds = 60
    ) {
        $this->defaultConfig = new CircuitBreakerConfig(
            failureThreshold: $failureThreshold,
            recoveryTimeout: Duration::fromSeconds($recoveryTimeoutSeconds),
            halfOpenMaxAttempts: 3,
            successThreshold: 2
        );
    }

    /**
     * Check if a middleware is allowed to execute
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     * @return bool True if the middleware is allowed to execute, false otherwise
     */
    public function isAllowed(string $middlewareName): bool
    {
        try {
            // Use the CircuitBreaker to check if the middleware is allowed to execute
            $this->circuitBreaker->check($this->getServiceName($middlewareName), $this->defaultConfig);

            return true;
        } catch (Throwable $e) {
            // If the circuit is open, the check method will throw an exception
            return false;
        }
    }

    /**
     * Record a successful middleware execution
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     */
    public function recordSuccess(string $middlewareName): void
    {
        // Delegate to the CircuitBreaker
        $this->circuitBreaker->recordSuccess($this->getServiceName($middlewareName), $this->defaultConfig);
    }

    /**
     * Record a middleware failure
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     * @param int|null $failureThreshold Custom failure threshold for this middleware
     * @param int|null $openTime Custom open time for this middleware
     */
    public function recordFailure(string $middlewareName, ?int $failureThreshold = null, ?int $openTime = null): void
    {
        // Create a custom config if custom thresholds are provided
        $config = $this->defaultConfig;
        if ($failureThreshold !== null || $openTime !== null) {
            $config = new CircuitBreakerConfig(
                failureThreshold: $failureThreshold ?? $this->defaultConfig->failureThreshold,
                recoveryTimeout: $openTime ? Duration::fromSeconds($openTime) : $this->defaultConfig->recoveryTimeout,
                halfOpenMaxAttempts: $this->defaultConfig->halfOpenMaxAttempts,
                successThreshold: $this->defaultConfig->successThreshold
            );
        }

        // Create a RuntimeException to pass to the CircuitBreaker
        $exception = new RuntimeException("Middleware {$middlewareName} failed");

        // Delegate to the CircuitBreaker
        $this->circuitBreaker->recordFailure($this->getServiceName($middlewareName), $exception, $config);
    }

    /**
     * Get the state of the circuit for a middleware
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     * @return CircuitState The current state of the circuit
     */
    public function getState(string $middlewareName): CircuitState
    {
        return $this->circuitBreaker->getState($this->getServiceName($middlewareName), $this->defaultConfig);
    }

    /**
     * Reset the circuit for a middleware
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     */
    public function reset(string $middlewareName): void
    {
        $this->circuitBreaker->reset($this->getServiceName($middlewareName));
    }

    /**
     * Get metrics for a middleware
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     * @return array Metrics for the middleware
     */
    public function getMetrics(string $middlewareName): array
    {
        return $this->circuitBreaker->getMetrics($this->getServiceName($middlewareName));
    }

    /**
     * Convert a middleware name to a service name for the CircuitBreaker
     *
     * @param string $middlewareName The fully qualified class name of the middleware
     * @return string The service name for the CircuitBreaker
     */
    private function getServiceName(string $middlewareName): string
    {
        return 'middleware:' . $middlewareName;
    }
}