# QualifiedIdentity.java

    /*
     * Copyright (c) 2007, Rickard Öberg. All Rights Reserved.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     *
     */

    package org.qi4j.spi.entity;

    import java.io.Serializable;
    import org.qi4j.api.Qi4j;
    import org.qi4j.api.entity.EntityComposite;
    import org.qi4j.api.util.Classes;

    import static org.qi4j.functional.Iterables.first;

    /**
     * A Qualified Identity is the combination of the Composite type name and the identity of a specific
     * Entity instance. When stringified, these two are separated by the ":" character. Example:
     * <pre>
     * com.mycompany.mydomain.SomeEntity:123456
     * </pre>
     * where "com.mycompany.mydomain.SomeEntity" is the Composite type, and "123456" is the identity.
     */
    public final class QualifiedIdentity
        implements Serializable
    {
        public static QualifiedIdentity parseURI( String uri )
        {
            String str = uri.substring( "urn:qi4j:entity:".length() );
            int idx = str.indexOf( "/" );
            String type = str.substring( 0, idx ).replace( "-", "$" );
            String identity = str.substring( idx + 1 );
            return new QualifiedIdentity( identity, type );
        }

        public static QualifiedIdentity parseQualifiedIdentity( String id )
        {
            return new QualifiedIdentity( id );
        }

        public static QualifiedIdentity qualifiedIdentityOf( Object o )
        {
            return new QualifiedIdentity( (EntityComposite) o );
        }

        private static final long serialVersionUID = 1L;

        // Associations who have been set to "null" should use this as the representation in the EntityState
        public static final QualifiedIdentity NULL = new QualifiedIdentity( "null", "none" );

        private String identity;
        private String compositeType;

        public QualifiedIdentity( EntityComposite entityComposite )
        {
            this( entityComposite.identity().get(), first( Qi4j.FUNCTION_DESCRIPTOR_FOR
                                                               .map( entityComposite )
                                                               .types() ).getName() );
        }

        public QualifiedIdentity( String identity, Class<?> clazz )
        {
            this.identity = identity;
            this.compositeType = clazz.getName();
        }

        public QualifiedIdentity( String identity, String clazz )
        {
            this.identity = identity;
            this.compositeType = clazz;
        }

        protected QualifiedIdentity( String qualifiedIdentity )
        {
            int separatorIndex = qualifiedIdentity.indexOf( ":" );
            if( separatorIndex == -1 )
            {
                throw new IllegalArgumentException( "Supplied string is not a qualified identity: " + qualifiedIdentity );
            }
            this.compositeType = qualifiedIdentity.substring( 0, separatorIndex );
            this.identity = qualifiedIdentity.substring( separatorIndex + 1 );
        }

        public final String identity()
        {
            return identity;
        }

        public final String type()
        {
            return compositeType;
        }

        public final String toURI()
        {
            return "urn:qi4j:entity:" + Classes.normalizeClassToURI( compositeType ) + "/" + identity;
        }

        @Override
        @SuppressWarnings( "AccessingNonPublicFieldOfAnotherObject" )
        public boolean equals( Object o )
        {
            if( this == o )
            {
                return true;
            }
            if( o == null || getClass() != o.getClass() )
            {
                return false;
            }
            QualifiedIdentity that = (QualifiedIdentity) o;
            return compositeType.equals( that.compositeType ) && identity.equals( that.identity );
        }

        @Override
        public int hashCode()
        {
            int result;
            result = identity.hashCode();
            result = 31 * result + compositeType.hashCode();
            return result;
        }

        @Override
        public String toString()
        {
            return compositeType + ":" + identity;
        }
    }