package model.pki.crl;

import model.asn1.ASN1Object;
import model.asn1.BitString;
import model.asn1.Tag;
import model.pki.AlgorithmIdentifier;

import java.util.Arrays;
import java.util.Collection;
import java.util.stream.Stream;

/**
 * Represents a signed X.509 CRL.
 * <pre>
 *      CertificateList ::= SIGNED{CertificateListContent}
 * </pre>
 */
public class CertificateList extends ASN1Object {
    /**
     * All info of that CRL, excluding the signature.
     * It will be signed, and the signature is in <pre>signature</pre>.
     */
    private final CertificateListContent crl;

    /**
     * The algorithm used for <pre>signature</pre>.
     */
    private final AlgorithmIdentifier signatureAlgorithm;

    /**
     * The signature.
     */
    private final BitString signature;

    /**
     * EFFECTS: Initialize the object with the given tag and parentTag, and list, signatureAlgorithm, and signature.
     * REQUIRES: The algorithm must match the signature. The fields must have correct tags as described in the class
     * specification (SEQUENCE, SEQUENCE, BIT STRING).
     */
    public CertificateList(Tag tag, Tag parentTag,
                           final CertificateListContent crl,
                           final AlgorithmIdentifier signatureAlgorithm,
                           final BitString signature) {
        super(tag, parentTag);
        this.crl = crl;
        this.signatureAlgorithm = signatureAlgorithm;
        this.signature = signature;
    }

    /**
     * EFFECT: Encode that sequence into an ordered array of bytes, following the class specification.
     */
    @Override
    public Byte[] encodeValueDER() {
        return Stream.of(Arrays.asList(crl.encodeDER()),
                        Arrays.asList(signatureAlgorithm.encodeDER()),
                        Arrays.asList(signature.encodeDER()))
                .flatMap(Collection::stream)
                .toArray(Byte[]::new);
    }

    public CertificateListContent getCrl() {
        return crl;
    }

    public AlgorithmIdentifier getSignatureAlgorithm() {
        return signatureAlgorithm;
    }

    public BitString getSignature() {
        return signature;
    }
}