EDIT

/**

* Copyright (C) 2009 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.model.common;

import java.io.Serializable;

import java.util.NoSuchElementException;

import java.util.StringTokenizer;

import javax.persistence.Embeddable;

import javax.persistence.Transient;

import com.ibm.lsid.MalformedLSIDException;

/**

 * This class is copied from com.ibm.lsid.LSID, I needed to re-implement this since

 * the domain objects are required to be Serializable

 *

 *

 * @author Ben Szekely (<a href="mailto:bhszekel@us.ibm.com">bhszekel@us.ibm.com</a>)

 * @author ben.clark

 * @see com.ibm.lsid.client.LSID

 */

@Embeddable

public class LSID implements Serializable {

	private static final long serialVersionUID = -3568951541851092269L;

	private String lsid;

	private String authority;

	private String namespace;

	private String object;

	private String revision;

	private LSID() { }

	/**

	 * Construct a new LSID with the String representation.

	 * @param String The lsid String respresentation

	 */

	public LSID(String lsid) throws MalformedLSIDException {

		if (lsid.endsWith(":")) {

			lsid = lsid.substring(0, lsid.length() - 1);

		}

		StringTokenizer st = new StringTokenizer(lsid, ":");

		// check for urn and lsid

		try {

			String urn = st.nextToken().toLowerCase();

			String l = st.nextToken().toLowerCase();

			if (!urn.equals("urn") || !l.equals("lsid")) {

				throw new MalformedLSIDException("urn:lsid: not found: [" + lsid + "]");

			}

		}

		catch (NoSuchElementException e) {

			throw new MalformedLSIDException(e, "urn:lsid: not found: [" + lsid + "]");

		}

		try {

			authority = st.nextToken().toLowerCase();

		}

		catch (NoSuchElementException e) {

			throw new MalformedLSIDException(e, "authority not found: [" + lsid + "]");

		}

		try {

			namespace = st.nextToken();

		}

		catch (NoSuchElementException e) {

			throw new MalformedLSIDException(e, "namespace not found: [" + lsid + "]");

		}

		try {

			object = st.nextToken();

		}

		catch (NoSuchElementException e) {

			throw new MalformedLSIDException(e, "object not found: [" + lsid + "]");

		}

		if (st.hasMoreTokens()) {

			revision = st.nextToken();

		}

		this.lsid = "urn:lsid:" + this.authority + ":" + this.namespace + ":" + this.object + (this.revision != null ? ":" + this.revision : "");

	}

	/**

	 * Construct a new LSID with the given components

	 * @param String the authority

	 * @param String the namespace

	 * @param String the object

	 * @param String the revision, can be null

	 */

	public LSID(String authority, String namespace, String object, String revision) throws MalformedLSIDException {

		this.authority = authority.toLowerCase();

		this.namespace = namespace;//.toLowerCase();

		this.object = object;//.toLowerCase();

		if (revision != null)

         {

            this.revision = revision;//.toLowerCase();

        }

		lsid = "urn:lsid:" + this.authority + ":" + this.namespace + ":" + this.object + (this.revision != null ? ":" + this.revision : "");

	}

	/**

	 * Returns the lsid

	 * @return String The lsid String representation

	 */

	public String getLsid() {

		return lsid;

	}

	/**

	 * Returns the authority component of the LSID

	 * @return LSIDAuthority the authority

	 */

	public String getAuthority() {

		return authority;

	}

	/**

	 * Returns the namespace component of the LSID

	 * @return String

	 */

	public String getNamespace() {

		return namespace;

	}

	/**

	 * Returns the object component of the LSID

	 * @return String

	 */

	public String getObject() {

		return object;

	}

	/**

	 * Returns the revision component of the LSID if it exists

	 * @return String

	 */

	public String getRevision() {

		return revision;

	}

	public static boolean isLsid(String strLsid){

		try {

			//TODO use algorithm rather than exceptions

			new LSID(strLsid);

			return true;

		} catch (MalformedLSIDException e) {

			return false;

		}

	}

    /**

     * <code>true</code>, if all of the LSID parts are

     * empty or <code>null</code>.

     */

    @Transient

    public boolean isEmpty(){

        if (isEmpty(authority) && isEmpty(lsid) &&

                isEmpty(namespace) && isEmpty(object) &&

                isEmpty(revision)){

            return true;

        }else{

            return false;

        }

    }

    private boolean isEmpty(String str) {

        return str == null || str.isEmpty();

    }

	/**

	 * return the string representation

	 * @return String

	 */

	@Override

    public String toString() {

		return lsid;

	}

	/**

	 * Two LSIDs are equal their string representations are equal disregarding case.

	 */

	@Override

    public boolean equals(Object lsid) {

		if(this == lsid) {

			return true;

		} else if (lsid != null && lsid instanceof LSID) {

			LSID theLSID = (LSID)lsid;

			return theLSID.toString().equals(toString());

		} else {

			return false;

		}

	}

}