package model.csr;

import annotations.Assoc;
import model.asn1.ASN1Object;
import model.asn1.Encodable;
import model.asn1.Tag;
import model.asn1.exceptions.ParseException;
import model.asn1.parsing.BytesReader;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Stream;

/**
 * Represents a CSR Attributes list.
 * <pre>
 *     Attributes { ATTRIBUTE:IOSet } ::= SET OF Attribute{{ IOSet }}
 * </pre>
 */
public class Attributes extends ASN1Object {
    @Assoc(partOf = true)
    private final Attribute[] array;

    /**
     * EFFECT: Initialize the list with the given tag, parentTag, and array. For tag and parentTag, consult
     * {@link ASN1Object}.
     */
    public Attributes(Tag tag, Tag parentTag, Attribute[] array) {
        super(tag, parentTag);
        this.array = array;
    }

    /**
     * EFFECT: Parse the list from input DER bytes. For details on parsing, refer to {@link ASN1Object}.
     * Throws {@link ParseException} for invalid input.
     * MODIFIES: this, encoded
     */
    public Attributes(BytesReader encoded, boolean hasParentTag) throws ParseException {
        super(encoded, hasParentTag);
        final List<Attribute> list = new ArrayList<>();
        for (int i = 0; i < getLength(); ) {
            int index = encoded.getIndex();
            final Attribute attribute = new Attribute(encoded, false);
            attribute.getTag().enforce(TAG_SEQUENCE);
            list.add(attribute);
            index = encoded.getIndex() - index;
            i += index;
        }
        this.array = list.toArray(new Attribute[0]);
    }

    /**
     * EFFECTS: Encode the SET OF into DER, keep order. Values will be encoded one-by-one.
     */
    @Override
    public Byte[] encodeValueDER() {
        return Stream.of(array)
                .map(Encodable::encodeDER)
                .flatMap(Arrays::stream)
                .toArray(Byte[]::new);
    }

    public Attribute[] getArray() {
        return array;
    }
}