/******************************************************************************
 * Copyright (c) 2016 Oracle
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Konstantin Komissarchik - initial implementation and ongoing maintenance
 ******************************************************************************/

package org.eclipse.sapphire;

import org.eclipse.sapphire.modeling.annotations.Reference;
import org.eclipse.sapphire.services.ReferenceService;

/**
 * @author <a href="mailto:konstantin.komissarchik@oracle.com">Konstantin Komissarchik</a>
 */

public final class ReferenceValue<R,T> extends Value<R>
{
    private ReferenceService<T> service;
    
    public ReferenceValue( final Element element, final ValueProperty property )
    {
        super( element, property );
    }
    
    /**
     * Returns a reference to ReferenceValue.class that is parameterized with the given types.
     * 
     * <p>Example:</p>
     * 
     * <p><code>Class<ReferenceValue<JavaTypeName,JavaType>> cl = ReferenceValue.of( JavaTypeName.class, JavaType.class );</code></p>
     *  
     * @param referenceType the reference type
     * @param targetType the target type
     * @return a reference to ReferenceValue.class that is parameterized with the given types
     */
    
    @SuppressWarnings( { "unchecked", "rawtypes" } )
    
    public static <RX,TX> Class<ReferenceValue<RX,TX>> of( final Class<RX> referenceType, final Class<TX> targetType )
    {
        return (Class) ReferenceValue.class;
    }
    
    @SuppressWarnings( "unchecked" )
    
    public T target()
    {
        synchronized( root() )
        {
            assertNotDisposed();
            
            if( this.service == null )
            {
                this.service = service( ReferenceService.class );
            }
            
            T result = null;
            
            if( this.service != null )
            {
                result = this.service.target();
            }
            
            return result;
        }
    }

    @Override
    @SuppressWarnings( "unchecked" )
    
    protected String convertToText( final Object content )
    {
        String text;
        
        if( definition().getAnnotation( Reference.class ).target().isInstance( content ) )
        {
            text = service( ReferenceService.class ).reference( content );
        }
        else
        {
            text = super.convertToText( content );
        }
        
        return text;
    }
    
}