EventController.php

<?php
namespace TracToGitlab;

abstract class EventController extends Controller
{
    private $payload = null;

    protected function verifySecret(string $secret): bool
    {
        return $_SERVER['HTTP_X_GITLAB_TOKEN'] === $secret;
    }

    protected function verifyEventType(string $type): bool
    {
        return $_SERVER['HTTP_X_GITLAB_EVENT'] === $type;
    }

    protected function getFromPayload(...$keys)
    {
        if ($this->payload === null) {
            $this->payload = $this->getPayloadFromRequest() ?? false;
        }
        if ($this->payload === false) {
            throw new \Exception('No payload detected');
        }

        $result = $this->payload;
        foreach ($keys as $key) {
            if (!isset($result[$key])) {
                throw new \Exception("Invalid payload key {$key}");
            }

            $result = $result[$key];
        }

        return $result;
    }

    private function getPayloadFromRequest(): ?array
    {
        $input =file_get_contents('php://input');
        if (!$input) {
            return null;
        }

        $payload = json_decode($input, true);
        if (!$payload || !is_array($payload)) {
            return null;
        }

        return $payload;
    }
}