/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.jss.asn1;

import java.io.IOException;
import java.io.InputStream;

/**
 * Represents an ASN.1 <code>ENUMERATED</code> value. This has the same
 * interface as <code>INTEGER</code>
 */
public class ENUMERATED extends INTEGER {

    private static final long serialVersionUID = 1L;
    public static final Tag TAG = new Tag(Tag.Class.UNIVERSAL, 10);

    @Override
    public Tag getTag() {
        return TAG;
    }

    /**
     * Creates a new ENUMERATED value from a long int.
     *
     * @param val Input value.
     */
    public ENUMERATED(long val) {
        super(val);
    }

    ENUMERATED(byte[] valBytes) {
        super(valBytes);
    }

    /**
     * @return The value as a long int.
     */
    public long getValue() {
        return longValue();
    }

    private static final ENUMERATED.Template templateInstance = new ENUMERATED.Template();

    public static ASN1Template getTemplate() {
        return templateInstance;
    }

    /**
     * A template for decoding ENUMERATED values from their BER encodings.
     * The template reads the value as an INTEGER. It does not check that it
     * is a valid value for the ENUMERATED type.
     */
    public static class Template
            extends INTEGER.Template {
        @Override
        Tag getTag() {
            return ENUMERATED.TAG;
        }

        @Override
        public boolean tagMatch(Tag tag) {
            return (tag.equals(ENUMERATED.TAG));
        }

        @Override
        public ASN1Value decode(Tag tag, InputStream derStream)
                throws InvalidBERException, IOException {
            try {
                ASN1Header wrapper = new ASN1Header(derStream);

                wrapper.validate(tag, FORM);

                // Is length < 1 ?
                if (wrapper.getContentLength() < 1) {
                    throw new InvalidBERException("Invalid 0 length for ENUMERATED");
                }

                byte[] valBytes = new byte[(int) wrapper.getContentLength()];
                ASN1Util.readFully(valBytes, derStream);
                return new ENUMERATED(valBytes);

            } catch (InvalidBERException e) {
                throw new InvalidBERException(e, "ENUMERATED");
            }
        }

    } // end of Template

}
