/*
 * Copyright (C) 2005-2007 Alfresco Software Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */
package org.alfresco.repo.jscript;

import java.util.Collection;
import java.util.List;

import org.alfresco.service.ServiceRegistry;
import org.alfresco.service.cmr.repository.ChildAssociationRef;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.service.cmr.repository.StoreRef;
import org.alfresco.service.cmr.search.CategoryService;
import org.alfresco.service.namespace.QName;
import org.alfresco.util.Pair;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Scriptable;

/**
 * Support class for finding categories, finding root nodes for categories and creating root categories. 
 * 
 * @author Andy Hind
 */
public final class Classification extends BaseScopableProcessorExtension
{
    private ServiceRegistry services;

    private StoreRef storeRef;
    
    /**
     * Set the default store reference
     * 
     * @param   storeRef the default store reference
     */
    public void setStoreUrl(String storeRef)
    {
        this.storeRef = new StoreRef(storeRef);
    }
    
    /**
     * Set the service registry
     * 
     * @param services  the service registry
     */
    public void setServiceRegistry(ServiceRegistry services)
    {
        this.services = services;
    }

    /**
     * Find all the category nodes in a given classification.
     * 
     * @param aspect
     * @return
     */
    public Scriptable getAllCategoryNodes(String aspect)
    {
        Object[] cats = buildCategoryNodes(services.getCategoryService().getCategories(
                            storeRef, createQName(aspect), CategoryService.Depth.ANY));
        return Context.getCurrentContext().newArray(getScope(), cats);
    }

    /**
     * Get all the aspects that define a classification.
     * 
     * @return
     */
    public String[] getAllClassificationAspects()
    {
        Collection<QName> aspects = services.getCategoryService().getClassificationAspects();
        String[] answer = new String[aspects.size()];
        int i = 0;
        for (QName qname : aspects)
        {
            answer[i++] = qname.toPrefixString(this.services.getNamespaceService());
        }
        return answer;
    }
    
    /**
     * Create a root category in a classification.
     * 
     * @param aspect
     * @param name
     */
    public CategoryNode createRootCategory(String aspect, String name)
    {
        NodeRef categoryNodeRef = services.getCategoryService().createRootCategory(storeRef, createQName(aspect), name);
        CategoryNode categoryNode = new CategoryNode(categoryNodeRef, this.services, getScope());

        return categoryNode;
    }

    /**
     * Get the root categories in a classification.
     * 
     * @param aspect
     * @return
     */
    public Scriptable getRootCategories(String aspect)
    {
        Object[] cats = buildCategoryNodes(services.getCategoryService().getRootCategories(
                            storeRef, createQName(aspect)));
        return Context.getCurrentContext().newArray(getScope(), cats);
    }

    /**
     * Get the category usage count.
     * 
     * @param aspect
     * @param maxCount
     * @return
     */
    public Scriptable getCategoryUsage(String aspect, int maxCount)
    {
        List<Pair<NodeRef, Integer>> topCats = services.getCategoryService().getTopCategories(storeRef, createQName(aspect), maxCount);
        Object[] tags = new Object[topCats.size()];
        int i = 0;
        for (Pair<NodeRef, Integer> topCat : topCats)
        {
           tags[i++] = new Tag(new CategoryNode(topCat.getFirst(), this.services, getScope()), topCat.getSecond());
        }
        
        return Context.getCurrentContext().newArray(getScope(), tags);
    }

    private Object[] buildCategoryNodes(Collection<ChildAssociationRef> cars)
    {
        Object[] categoryNodes = new Object[cars.size()];
        int i = 0;
        for (ChildAssociationRef car : cars)
        {
            categoryNodes[i++] = new CategoryNode(car.getChildRef(), this.services, getScope());
        }
        return categoryNodes;
    }

    private QName createQName(String s)
    {
        QName qname;
        if (s.indexOf(QName.NAMESPACE_BEGIN) != -1)
        {
            qname = QName.createQName(s);
        }
        else
        {
            qname = QName.createQName(s, this.services.getNamespaceService());
        }
        return qname;
    }
    
    /**
     * Tag class returned from getCategoryUsage().
     * 
     * @param CategoryNode
     * @param frequency
     * @return
     */
    public final class Tag
    {
        private CategoryNode categoryNode;
        private int frequency = 0;
       
        public Tag(CategoryNode categoryNode, int frequency)
        {
            this.categoryNode = categoryNode;
            this.frequency = frequency;
        }
       
        public CategoryNode getCategory()
        {
            return categoryNode;
        }
       
        public int getFrequency()
        {
            return frequency;
        }
     }
}