/*
 * ============================================================================
 * GNU Lesser General Public License
 * ============================================================================
 *
 * Beanlet - JSE Application Container.
 * Copyright (C) 2006  Leon van Zantvoort
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
 *
 * Leon van Zantvoort
 * 243 Acalanes Drive #11
 * Sunnyvale, CA 94086
 * USA
 *
 * zantvoort@users.sourceforge.net
 * http://beanlet.org
 */
package org.beanlet.impl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.beanlet.annotation.Element;
import org.beanlet.plugin.DependencyInjection;
import org.beanlet.plugin.DependencyInjectionFactory;

/**
 * @author Leon van Zantvoort
 */
public final class LinkedDependencyInjectionFactory implements
        DependencyInjectionFactory {
    
    private final List<DependencyInjectionFactory> factories;
    
    public LinkedDependencyInjectionFactory(
            List<DependencyInjectionFactory> factories) {
        this.factories = factories;
    }
    
    public List<DependencyInjection> getConstructorDependencyInjections(
            final Class<?> cls) {
        return new DependencyInjectionRetriever() {
            List<DependencyInjection> retrieve(DependencyInjectionFactory 
                    factory) {
                return factory.getConstructorDependencyInjections(cls);
            }
        }.getDependencyInjections();
    }
    
    public List<DependencyInjection> getSetterDependencyInjections(
            final Class<?> cls) {
        return new DependencyInjectionRetriever() {
            List<DependencyInjection> retrieve(DependencyInjectionFactory 
                    factory) {
                return factory.getSetterDependencyInjections(cls);
            }
        }.getDependencyInjections();
    }
    
    public List<DependencyInjection> getFactoryDependencyInjections(
            final Class<?> cls, final String factoryMethod) {
        return new DependencyInjectionRetriever() {
            List<DependencyInjection> retrieve(DependencyInjectionFactory 
                    factory) {
                return factory.getFactoryDependencyInjections(cls, 
                        factoryMethod);
            }
        }.getDependencyInjections();
    }
    
    /**
     * Abstract class that prevents code duplication within the outer class.
     */
    private abstract class DependencyInjectionRetriever {
        
        List<DependencyInjection> getDependencyInjections() {
            Map<Element, List<DependencyInjection>> map = 
                    new LinkedHashMap<Element, List<DependencyInjection>>();
            for (DependencyInjectionFactory factory : factories) {
                for (DependencyInjection i : retrieve(factory)) {
                    List<DependencyInjection> list = map.get(i.getTarget());
                    if (list == null) {
                        list = new ArrayList<DependencyInjection>();
                        map.put(i.getTarget(), list);
                    }
                    list.add(i);
                }
            }
            // Yes I know, this is not a linked list implementation ;-)
            List<DependencyInjection> linkedList = 
                    new ArrayList<DependencyInjection>();
            for (List<DependencyInjection> list : map.values()) {
                linkedList.add(new LinkedDependencyInjection(list));
            }
            return Collections.unmodifiableList(linkedList);
        }
        
        abstract List<DependencyInjection> retrieve(
                DependencyInjectionFactory factory);
    }
}