<?php
/**
 * This file is part of the FreeDSx ASN1 package.
 *
 * (c) Chad Sikorra <Chad.Sikorra@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace FreeDSx\Asn1\Encoder;

use FreeDSx\Asn1\Exception\EncoderException;
use FreeDSx\Asn1\Type\AbstractStringType;
use FreeDSx\Asn1\Type\AbstractTimeType;
use FreeDSx\Asn1\Type\AbstractType;
use FreeDSx\Asn1\Type\BitStringType;
use FreeDSx\Asn1\Type\OctetStringType;
use FreeDSx\Asn1\Type\SetTrait;
use FreeDSx\Asn1\Type\SetType;

/**
 * Distinguished Encoding Rules (DER) encoder.
 *
 * @author Chad Sikorra <Chad.Sikorra@gmail.com>
 */
class DerEncoder extends BerEncoder
{
    use CerDerTrait,
        SetTrait;

    /**
     * @param array $options
     */
    public function __construct(array $options = [])
    {
        parent::__construct($options);
        $this->setOptions([
            'bitstring_padding' => '0',
        ]);
    }

    public function encode(AbstractType $type): string
    {
        $this->validate($type);

        return parent::encode($type);
    }

    /**
     * {@inheritdoc}
     */
    protected function decodeBytes(bool $isRoot = false, $tagType = null, $length = null, $isConstructed = null, $class = null): AbstractType
    {
        $type = parent::decodeBytes($isRoot, $tagType, $length, $isConstructed, $class);
        $this->validate($type);

        return $type;
    }

    /**
     * {@inheritdoc}
     */
    protected function decodeLongDefiniteLength(int $length) : int
    {
        $length = parent::decodeLongDefiniteLength($length);

        if ($length < 127) {
            throw new EncoderException('DER must be encoded using the shortest possible length form, but it is not.');
        }

        return $length;
    }

    /**
     * {@inheritdoc}
     * @throws EncoderException
     */
    protected function encodeSet(SetType $set)
    {
        return $this->encodeConstructedType(...$this->canonicalize(...$set->getChildren()));
    }

    /**
     * @param AbstractType $type
     * @throws EncoderException
     */
    protected function validate(AbstractType $type) : void
    {
        if ($type instanceof OctetStringType && $type->getIsConstructed()) {
            throw new EncoderException('The octet string must be primitive. It cannot be constructed.');
        }
        if ($type instanceof BitStringType && $type->getIsConstructed()) {
            throw new EncoderException('The bit string must be primitive. It cannot be constructed.');
        }
        if ($type instanceof AbstractStringType && $type->isCharacterRestricted() && $type->getIsConstructed()) {
            throw new EncoderException('Character restricted string types must be primitive.');
        }
        if ($type instanceof AbstractTimeType) {
            $this->validateTimeType($type);
        }
    }
}