Fetch pairs from entity object.

Doctrine entity pairs

	public function getPairs(array $source, string $key, string $value): array
	{
		$result = [];
		$methodPrefixes = ['get', 'is'];

		$methodName = function (string $prefix, string $column) {
			return $prefix . Strings::firstUpper($column);
		};

		$getAllProperties = function ($class) {
			$properties = [];
			try {
				$rc = new \ReflectionClass($class);
				do {
					$rp = [];
					/* @var $p \ReflectionProperty */
					foreach ($rc->getProperties() as $p) {
						$p->setAccessible(true);
						$rp[$p->getName()] = $p->getValue($class);
					}
					/** @noinspection SlowArrayOperationsInLoopInspection */
					$properties = array_merge($rp, $properties);
				} while ($rc = $rc->getParentClass());
			} catch (\ReflectionException $e) {
			}

			return $properties;
		};

		foreach ($source as $entity) {
			$entityProperties = $getAllProperties($entity);

			if (isset($entityProperties[$key], $entityProperties[$value])) {
				$keyMethodName = null;
				$valueMethodName = null;

				foreach ($methodPrefixes as $prefix) {
					!method_exists($entity, $methodName($prefix, $key)) ?: $keyMethodName = $methodName($prefix, $key);
					!method_exists($entity, $methodName($prefix, $value)) ?: $valueMethodName = $methodName($prefix, $value);
				}

				$result[$entity->{$keyMethodName}()] = $entity->{$valueMethodName}();
			}
		}

		return $result;
	}