package model.x501;

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.Collectors;
import java.util.stream.Stream;

/**
 * Represents a DN item.
 * <pre>
 *      RelativeDistinguishedName ::= SET SIZE (1..MAX) OF AttributeTypeAndValue
 * </pre>
 * For more information on DN, see {@link Name}.
 */
public class RelativeDistinguishedName extends ASN1Object {
    private final AttributeTypeAndValue[] array;

    /**
     * EFFECT: Initialize the list with the given tag, parentTag, and array. For tag and parentTag, consult
     * {@link ASN1Object}.
     * REQUIRES: Array items should have UNIVERSAL SEQUENCE tag.
     */
    public RelativeDistinguishedName(Tag tag, Tag parentTag, AttributeTypeAndValue[] 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 RelativeDistinguishedName(BytesReader encoded, boolean hasParentTag) throws ParseException {
        super(encoded, hasParentTag);
        final List<AttributeTypeAndValue> list = new ArrayList<>();
        for (int i = 0; i < getLength(); ) {
            int index = encoded.getIndex();
            final AttributeTypeAndValue value = new AttributeTypeAndValue(encoded, false);
            value.getTag().enforce(TAG_SEQUENCE);
            list.add(value);
            index = encoded.getIndex() - index;
            i += index;
        }
        this.array = list.toArray(new AttributeTypeAndValue[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);
    }

    /**
     * EFFECT: Encode into multi-valed RDN strings like CN=yuuta+CN=qwq
     */
    @Override
    public String toString() {
        return Stream.of(array)
                .map(AttributeTypeAndValue::toString)
                .collect(Collectors.joining("+"));
    }

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