/**
 * The MIT License
 *
 * Copyright (c) 2010-2011 Sonatype, Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package org.hudsonci.utils.id;

import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamAsAttribute;

import java.util.UUID;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Globally Unique IDentifier; backed by {@link UUID}.
 *
 * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
 * @since 2.1.0
 */
@XStreamAlias("guid")
public class GUID
    implements ID
{
    @XStreamAsAttribute
    private final UUID value;

    public GUID(final UUID value) {
        this.value = checkNotNull(value);
    }

    public GUID(final String value) {
        this(UUID.fromString(value));
    }

    public GUID() {
        this(UUID.randomUUID());
    }

    public UUID getValue() {
        return value;
    }

    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof GUID)) {
            return false;
        }

        GUID that = (GUID) obj;

        return !(value != null ? !value.equals(that.value) : that.value != null);
    }

    @Override
    public int hashCode() {
        return value != null ? value.hashCode() : 0;
    }

    @Override
    public String toString() {
        return value.toString();
    }
}