/*************************************************************************
 *                                                                       *
 *  CERT-CVC: EAC 1.11 Card Verifiable Certificate Library               * 
 *                                                                       *
 *  This software is free software; you can redistribute it and/or       *
 *  modify it under the terms of the GNU Lesser General Public           *
 *  License as published by the Free Software Foundation; either         *
 *  version 2.1 of the License, or any later version.                    *
 *                                                                       *
 *  See terms of license at gnu.org.                                     *
 *                                                                       *
 *************************************************************************/
package org.ejbca.cvc;

import java.io.IOException;

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERTaggedObject;

/**
 * Represents Object Identifier
 * 
 * @author Keijo Kurkinen, Swedish National Police Board
 * @version $Id: OIDField.java 20720 2015-02-19 16:56:59Z mikekushner $
 * 
 */
public class OIDField extends AbstractDataField {

    private static final long serialVersionUID = 5212215839749666908L;
    private String id;

    OIDField() {
	super(CVCTagEnum.OID);
    }

    /**
     * Constructs a new instance from a String (the oid value)
     * 
     * @param id
     */
    OIDField(String id) {
	this();
	this.id = id;
    }

    /**
     * Constructs a new instance by parsing DER-encoded data
     * 
     * @param data
     */
    OIDField(byte[] data) {
	this();
	// For BC 1.46/1.47
	// this.id = ASN1ObjectIdentifier.getInstance(new DERTaggedObject(true,
	// 0, new DEROctetString(data)), false).getId();
	// For BC 1.45
	// this.id = DERObjectIdentifier.getInstance(new
	// DEROctetString(data)).getId();

	// For all BC versions
	// Create an octet string, generate it's encoding and replace the tag at
	// the start with the object identifier tag. You could then recover the
	// OID
	// using ASN1Object.fromByteArray().
	// BC 1.47 changed to ASN1Primitive though, so no reason to keep BC 1.45
	// compatibility, since it will not work anyway.
	this.id = ASN1ObjectIdentifier.getInstance(new DERTaggedObject(true, 0, new DEROctetString(data)), false)
		.getId();
    }

    public String getValue() {
	return id;
    }

    @Override
    protected byte[] getEncoded() {
	byte[] encoding = null;
	try {
	    // This will give the entire field in encoded format (starting with
	    // tag and length)
	    byte[] derField = new ASN1ObjectIdentifier(id).getEncoded();

	    // Skip the first two bytes, they will be added later. Note: In
	    // theory, Length could
	    // involve more than one byte, but for an OID it seems highly
	    // unlikely.
	    encoding = new byte[derField.length - 2];
	    System.arraycopy(derField, 2, encoding, 0, encoding.length);
	    return encoding;
	} catch (IOException e) {
	    throw new RuntimeException(e.getMessage());
	}
    }

    @Override
    protected String valueAsText() {
	return id;
    }

    public String toString() {
	return getValue();
    }

    @Override
    public boolean equals(Object other) {
	if (other instanceof OIDField) {
	    return id.equals(((OIDField) other).getValue());
	} else {
	    return false;
	}
    }

}