/*
* Copyright (c) 2008, Michael Hunger 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.bootstrap;
import org.qi4j.api.common.MetaInfo;
import org.qi4j.api.property.Property;
import java.lang.reflect.*;
import java.util.HashMap;
import java.util.Map;
/**
* Declaration of a Property or Association.
*/
public final class MetaInfoDeclaration
implements StateDeclarations, AssociationDeclarations, ManyAssociationDeclarations
{
Map<Class<?>, InfoHolder<?>> mixinPropertyDeclarations = new HashMap<Class<?>, InfoHolder<?>>();
public MetaInfoDeclaration()
{
}
public <T> MixinDeclaration<T> on( Class<T> mixinType )
{
InfoHolder<T> propertyDeclarationHolder = (InfoHolder<T>) mixinPropertyDeclarations.get( mixinType );
if( propertyDeclarationHolder == null )
{
propertyDeclarationHolder = new InfoHolder<T>( mixinType );
mixinPropertyDeclarations.put( mixinType, propertyDeclarationHolder );
}
return propertyDeclarationHolder;
}
public MetaInfo getMetaInfo( AccessibleObject accessor )
{
for( Map.Entry<Class<?>, InfoHolder<?>> entry : mixinPropertyDeclarations.entrySet() )
{
InfoHolder<?> holder = entry.getValue();
MetaInfo metaInfo = holder.getMetaInfo( accessor );
if( metaInfo != null )
{
Class<?> mixinType = entry.getKey();
return metaInfo.withAnnotations( mixinType )
.withAnnotations( accessor )
.withAnnotations( accessor instanceof Method ? ((Method)accessor).getReturnType() : ((Field)accessor).getType() );
}
}
// TODO is this code reached at all??
Class<?> declaringType = ((Member)accessor).getDeclaringClass();
return new MetaInfo().withAnnotations( declaringType )
.withAnnotations( accessor )
.withAnnotations( accessor instanceof Method ? ((Method)accessor).getReturnType() : ((Field)accessor).getType() );
}
public Object getInitialValue( AccessibleObject accessor )
{
for( InfoHolder<?> propertyDeclarationHolder : mixinPropertyDeclarations.values() )
{
final Object initialValue = propertyDeclarationHolder.getInitialValue( accessor );
if( initialValue != null )
{
return initialValue;
}
}
return null;
}
@Override
public boolean isUseDefaults( AccessibleObject accessor )
{
for( InfoHolder<?> propertyDeclarationHolder : mixinPropertyDeclarations.values() )
{
final boolean useDefaults = propertyDeclarationHolder.isUseDefaults( accessor );
if( useDefaults)
{
return useDefaults;
}
}
return false;
}
private static class InfoHolder<T>
implements InvocationHandler, StateDeclarations, MixinDeclaration<T>
{
private final static class MethodInfo
{
Object initialValue;
boolean useDefaults;
MetaInfo metaInfo;
private MethodInfo( MetaInfo metaInfo )
{
this.metaInfo = metaInfo;
}
}
private final Class<T> mixinType;
private final Map<AccessibleObject, MethodInfo> methodInfos = new HashMap<AccessibleObject, MethodInfo>();
// temporary holder
private MetaInfo metaInfo = null;
public InfoHolder( Class<T> mixinType )
{
this.mixinType = mixinType;
}
public Object invoke( Object o, Method method, Object[] objects )
throws Throwable
{
final MethodInfo methodInfo = new MethodInfo( metaInfo );
methodInfo.useDefaults = true;
methodInfos.put( method, methodInfo );
metaInfo = null; // reset
final Class<?> returnType = method.getReturnType();
try
{
return Proxy.newProxyInstance( returnType.getClassLoader(), new Class[]{ returnType },
new InvocationHandler()
{
public Object invoke( Object o, Method method, Object[] objects )
throws Throwable
{
if( method.getName().equals( "set" ) )
{
methodInfo.initialValue = objects[ 0 ];
}
return null;
}
} );
}
catch( IllegalArgumentException e )
{
throw new IllegalArgumentException(
"Only methods with " + Property.class.getName() + " as return type can have declareDefaults()" );
}
}
public MethodInfo matches( AccessibleObject accessor )
{
return methodInfos.get( accessor );
}
public MetaInfo getMetaInfo( AccessibleObject accessor )
{
final MethodInfo methodInfo = matches( accessor );
if( methodInfo == null )
{
return null;
}
return methodInfo.metaInfo;
}
public Object getInitialValue( AccessibleObject accessor )
{
final MethodInfo methodInfo = matches( accessor );
if( methodInfo == null )
{
return null;
}
return methodInfo.initialValue;
}
@Override
public boolean isUseDefaults( AccessibleObject accessor )
{
final MethodInfo methodInfo = matches( accessor );
if( methodInfo == null )
{
return false;
}
return methodInfo.useDefaults;
}
// DSL Interface
public T declareDefaults()
{
return mixinType.cast(
Proxy.newProxyInstance( mixinType.getClassLoader(), new Class[]{ mixinType }, this ) );
}
public MixinDeclaration<T> setMetaInfo( Object info )
{
if( metaInfo == null )
{
metaInfo = new MetaInfo();
}
metaInfo.set( info );
return this;
}
}
}