public function push(OperationInterface $newOperation)
{
$lastOperation = ($index = count($this->operations)) > 0 ? $this->operations[$index - 1] : null;
if ($lastOperation instanceof OperationInterface) {
if ($lastOperation->getType() === OperationInterface::TYPE_DELETE && $newOperation->getType() === OperationInterface::TYPE_DELETE) {
$this->operations->set($index - 1, new DeleteOperation($lastOperation->getValue() + $newOperation->getValue()));
return $this;
}
if ($lastOperation->getType() === OperationInterface::TYPE_DELETE && $newOperation->getType() === OperationInterface::TYPE_INSERT) {
$index -= 1;
if (!isset($this->operations[$index - 1])) {
$this->operations->unshift($newOperation);
return $this;
}
$lastOperation = $this->operations[$index - 1];
}
if ($lastOperation->getAttributes() === $newOperation->getAttributes()) {
if ($newOperation->getType() === OperationInterface::TYPE_INSERT && is_string($newOperation->getValue()) && $lastOperation->getType() === OperationInterface::TYPE_INSERT && is_string($lastOperation->getValue())) {
$this->operations[$index - 1] = new InsertOperation($lastOperation->getValue() . $newOperation->getValue(), $newOperation->getAttributes());
return $this;
} elseif ($newOperation->getType() === OperationInterface::TYPE_RETAIN && $lastOperation->getType() === OperationInterface::TYPE_RETAIN) {
$this->operations[$index - 1] = new RetainOperation($lastOperation->getValue() + $newOperation->getValue(), $newOperation->getAttributes());
return $this;
}
}
}
if ($index === count($this->operations)) {
$this->operations->add($newOperation);
} else {
$this->operations->splice($index, 0, $newOperation);
}
return $this;
}
private function calculateLength(OperationInterface $operation)
{
if ($operation->getType() === OperationInterface::TYPE_DELETE || $operation->getType() === OperationInterface::TYPE_RETAIN) {
return $operation->getValue();
}
return $operation->getType() == OperationInterface::TYPE_INSERT && is_string($operation->getValue()) ? mb_strlen($operation->getValue()) : 1;
}