state.php

<?php
 
namespace Bitrix\Sale\Discount\Preset;
 
 
use Bitrix\Main\HttpRequest;
use Bitrix\Main\Type\Dictionary;
use Bitrix\Main\Security\Sign\Signer;
 
final class State extends Dictionary
{
    private const STATE_NAME_VAR = '__state';
    private const CHAIN_NAME_VAR = '__chain';
    private const STATE_SIGNER_SALT = 'discount.preset.state';
 
    private $signer = null;
 
    public function __construct(array $values = null)
    {
        parent::__construct($values);
 
        $this->setDefaultValues();
        $this->initSigner();
    }
 
    private function setDefaultValues()
    {
        if(empty($this[self::CHAIN_NAME_VAR]))
        {
            $this[self::CHAIN_NAME_VAR] = array();
        }
    }
 
    private function initSigner(): void
    {
        $this->signer = new Signer();
    }
 
    private function sign(string $data): string
    {
        return $this->signer->sign($data, self::STATE_SIGNER_SALT);
    }
 
    public function unSign(string $data): string
    {
        try
        {
            $signedData = $this->signer->unsign($data, self::STATE_SIGNER_SALT);
        }
        catch(\Bitrix\Main\Security\Sign\BadSignatureException $e)
        {
            die('Bad signature.');
        }
        return $signedData;
    }
 
    public function set($name, $value = null)
    {
        parent::set($name, $value);
 
        $this->setDefaultValues();
 
        return $this;
    }
 
    public function append(array $values)
    {
        foreach($values as $name => $value)
        {
            $this[$name] = $value;
        }
 
        return $this;
    }
 
    public function get($name, $defaultValue = null)
    {
        $value = parent::get($name);
        if ($defaultValue && is_callable($defaultValue))
        {
            return $defaultValue($value);
        }
 
        return $value !== null? $value : $defaultValue;
    }
 
    public static function createFromEncodedData($data)
    {
        $state = new State;
 
        if(empty($data))
        {
            return $state;
        }
 
        $data = $state->unSign($data);
 
        $data = base64_decode($data);
        if($data === false)
        {
            return $state;
        }
        $data = unserialize($data, ['allowed_classes' => ['Bitrix\Main\Type\DateTime', 'DateTime']]);
 
        return $state->set($data?: array());
    }
 
    public static function createFromRequest(HttpRequest $request)
    {
        $prevState = self::createFromEncodedData($request->getPost(self::STATE_NAME_VAR));
 
        $postData = array();
        foreach($request->getPostList()->toArray() as $name => $data)
        {
            if(is_array($data) && count($data) === 1 && ($data[0] !== '0' && empty($data[0])))
            {
                //empty array
                unset($prevState[$name]);
                continue;
            }
 
            if(is_array($data) && ($data[0] !== '0' && empty($data[0])))
            {
                unset($data[0]);
            }
            $postData[$name] = $data;
        }
 
        return new State(array_merge($prevState->toArray(), $postData));
    }
 
    public function addStepChain($step)
    {
        $chain = $this[self::CHAIN_NAME_VAR];
        $lastStep = end($chain);
 
        if($lastStep != $step)
        {
            $chain[] = $step;
            $this[self::CHAIN_NAME_VAR] = $chain;
        }
 
        return $this;
    }
 
    public function popStepChain()
    {
        $chain = $this[self::CHAIN_NAME_VAR];
        $step = array_pop($chain);
 
        $this[self::CHAIN_NAME_VAR] = $chain;
 
        return $step;
    }
 
    public function getPrevStep()
    {
        return end($this[self::CHAIN_NAME_VAR]);
    }
 
    private function getStepChain(): array
    {
        return $this->get(self::CHAIN_NAME_VAR, array());
    }
 
    public function __toString()
    {
        $data = $this->toArray();
        $value = $this->sign(base64_encode(serialize($data)));
 
        return '<input type="hidden" name="' . self::STATE_NAME_VAR . '" value="' . $value . '">';
    }
 
    public function toString()
    {
        return $this->__toString();
    }
 
    public function toArray()
    {
        $toArray = parent::toArray();
 
        unset(
            $toArray['sessid'],
            $toArray['lang'],
            $toArray['__next_step']
        );
 
        return $toArray;
    }
 
    public function getStepNumber()
    {
        $countPrevSteps = count($this->getStepChain());
 
        return $countPrevSteps + 1;
    }
}