/*
* Demoiselle Framework
* Copyright (C) 2010 SERPRO
* ----------------------------------------------------------------------------
* This file is part of Demoiselle Framework.
*
* Demoiselle Framework is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License version 3
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License version 3
* along with this program; if not, see <http://www.gnu.org/licenses/>
* or write to the Free Software Foundation, Inc., 51 Franklin Street,
* Fifth Floor, Boston, MA 02110-1301, USA.
* ----------------------------------------------------------------------------
* Este arquivo é parte do Framework Demoiselle.
*
* O Framework Demoiselle é um software livre; você pode redistribuí-lo e/ou
* modificá-lo dentro dos termos da GNU LGPL versão 3 como publicada pela Fundação
* do Software Livre (FSF).
*
* Este programa é distribuído na esperança que possa ser útil, mas SEM NENHUMA
* GARANTIA; sem uma garantia implícita de ADEQUAÇÃO a qualquer MERCADO ou
* APLICAÇÃO EM PARTICULAR. Veja a Licença Pública Geral GNU/LGPL em português
* para maiores detalhes.
*
* Você deve ter recebido uma cópia da GNU LGPL versão 3, sob o título
* "LICENCA.txt", junto com esse programa. Se não, acesse <http://www.gnu.org/licenses/>
* ou escreva para a Fundação do Software Livre (FSF) Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02111-1301, USA.
*/
package br.gov.frameworkdemoiselle.internal.implementation;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.enterprise.inject.AmbiguousResolutionException;
import javax.enterprise.inject.spi.Bean;
import br.gov.frameworkdemoiselle.DemoiselleException;
import br.gov.frameworkdemoiselle.annotation.Priority;
import br.gov.frameworkdemoiselle.internal.producer.ResourceBundleProducer;
import br.gov.frameworkdemoiselle.util.Beans;
import br.gov.frameworkdemoiselle.util.ResourceBundle;
public final class StrategySelector implements Serializable {
private static final long serialVersionUID = 1L;
private static ResourceBundle bundle;
private StrategySelector() {
}
private static ResourceBundle getBundle() {
if (bundle == null) {
bundle = ResourceBundleProducer.create("demoiselle-core-bundle");
}
return bundle;
}
@SuppressWarnings("unchecked")
public static <T> T selectInstance(Class<T> type, Collection<? extends T> options) {
Map<Class<? extends T>, T> map = new HashMap<Class<? extends T>, T>();
for (T instance : options) {
if (instance != null) {
map.put((Class<T>) instance.getClass(), instance);
}
}
Class<? extends T> elected = selectClass(type, map.keySet());
return map.get(elected);
}
private static <T> Class<? extends T> selectClass(Class<T> type, Collection<Class<? extends T>> options) {
Class<? extends T> selected = null;
for (Class<? extends T> option : options) {
if (selected == null || getPriority(option) < getPriority(selected)) {
selected = option;
}
}
if (selected != null) {
performAmbiguityCheck(type, selected, options);
}
return selected;
}
public static <T> Class<? extends T> selectClass(Class<T> type) {
return selectClass(type, getOptions(type));
}
@SuppressWarnings("unchecked")
private static <T> Collection<Class<? extends T>> getOptions(Class<T> type) {
Set<Class<? extends T>> result = new HashSet<Class<? extends T>>();
for (Bean<?> bean : Beans.getBeanManager().getBeans(type)) {
result.add((Class<? extends T>) bean.getBeanClass());
}
return result;
}
private static <T> void performAmbiguityCheck(Class<T> type, Class<? extends T> selected,
Collection<Class<? extends T>> options) {
int selectedPriority = getPriority(selected);
List<Class<? extends T>> ambiguous = new ArrayList<Class<? extends T>>();
for (Class<? extends T> option : options) {
if (selected != option && selectedPriority == getPriority(option)) {
ambiguous.add(option);
}
}
if (!ambiguous.isEmpty()) {
ambiguous.add(selected);
String message = getExceptionMessage(type, ambiguous);
throw new DemoiselleException(message, new AmbiguousResolutionException());
}
}
private static <T> String getExceptionMessage(Class<T> type, List<Class<? extends T>> ambiguous) {
StringBuffer classes = new StringBuffer();
int i = 0;
for (Class<? extends T> clazz : ambiguous) {
if (i++ != 0) {
classes.append(", ");
}
classes.append(clazz.getCanonicalName());
}
return getBundle().getString("ambiguous-strategy-resolution", type.getCanonicalName(), classes.toString());
}
private static <T> int getPriority(Class<T> type) {
int result = Priority.MAX_PRIORITY;
Priority priority = type.getAnnotation(Priority.class);
if (priority != null) {
result = priority.value();
}
return result;
}
}