/**
 * This file is part of the CRISTAL-iSE kernel.
 * Copyright (c) 2001-2014 The CRISTAL Consortium. All rights reserved.
 *
 * 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 3 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; with out 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.
 *
 * http://www.fsf.org/licensing/licenses/lgpl.html
 */
package com.c2kernel.collection;

import java.util.Iterator;

import com.c2kernel.common.InvalidCollectionModification;
import com.c2kernel.common.ObjectAlreadyExists;
import com.c2kernel.common.ObjectNotFound;
import com.c2kernel.entity.C2KLocalObject;
import com.c2kernel.graph.model.GraphModel;
import com.c2kernel.lookup.ItemPath;
import com.c2kernel.persistency.ClusterStorage;
import com.c2kernel.utils.CastorHashMap;

/**
 * Collections are Item local objects that reference other Items.
 * 
 * <p>In parallel with the OO meta-model, Items can be linked to other Items in
 * different ways. These links are modelled with Collections, which are local
 * objects stored in an Item which reference a number of other Items in the same
 * server. The Collections holds a CollectionMember, sometimes known as a slot,
 * to reference each Item and store additional information about the link.
 * 
 * <p>Features:
 * <ul>
 * <li><b>Typing</b> - Collections can restrict membership of based on type 
 * information derived from Item, Property and Collection descriptions. This
 * restriction may be per-slot or apply to the whole Collection.
 * 
 * <li><b>Fixed or flexible slots</b> - The CollectionMember objects of a
 * Collection may be empty, individually typed, or created and removed as
 * required, simulating either array, structures or lists.
 * 
 * <li><b>Layout</b> - Collections can include a {@link GraphModel} to lay out
 * its slots on a two-dimensional canvas, for modelling real world compositions.
 * </ul>
 * 
 * <p>Collections are managed through predefined steps.
 */
abstract public class Collection<E extends CollectionMember> implements C2KLocalObject
{

	public static final short EMPTY = -1;
    private int mCounter = -1;      // Contains next available Member ID
    protected CollectionMemberList<E> mMembers = new CollectionMemberList<E>();
    protected int mID = -1;
    protected String mName = "";     // Not checked for uniqueness
    protected Integer mVersion = null;

	public int getCounter()
    {
        if (mCounter == -1)
			for (E element : mMembers.list) {
            if (mCounter < element.getID())
                mCounter = element.getID();
        }
        return ++mCounter;
    }

	public void setCounter(int count)
    {
        mCounter = count;
    }


	public int size()
    {
        return mMembers.list.size();
    }

    public void setID(int id)
    {
        mID = id;
    }

    public int getID()
    {
        return mID;
    }

	@Override
	public void setName(String name)
    {
        mName = name;
    }

	@Override
	public String getName()
    {
        return mName;
    }
	
	public Integer getVersion() {
		return mVersion;
	}

	public void setVersion(Integer mVersion) {
		this.mVersion = mVersion;
	}

	public String getVersionName() {
		return mVersion==null?"last":String.valueOf(mVersion);
	}
	@Override
	public String getClusterType()
    {
        return ClusterStorage.COLLECTION;
    }

	public void setMembers(CollectionMemberList<E> newMembers)
    {
    	mMembers = newMembers;
    }

    public boolean contains(ItemPath itemPath) {
        for (E element : mMembers.list) {
            if (element.getItemPath().equals(itemPath))
                return true;
        }
        return false;
    }
    
    public String getDescVer(E mem) {
    	String descVer = "last";
    	Object descVerObj = mem.getProperties().get("Version");
    	if (descVerObj != null) descVer = descVerObj.toString();
    	return descVer;
    }

    public boolean isFull()
    {
    	for (E element : mMembers.list) {
            if (element.getItemPath() == null)
                return false;
    	}
    	return true;
    }

	public E getMember(int memberId) throws ObjectNotFound {
        for (E element : mMembers.list) {
            if (element.getID() == memberId)
                return element;
        }
        throw new ObjectNotFound("Member "+memberId+" not found in "+mName);
    }

	public CollectionMemberList<E> getMembers()
    {
        return mMembers;
    }

	public abstract E addMember(ItemPath itemPath, CastorHashMap props, String classProps) throws InvalidCollectionModification, ObjectAlreadyExists;
	
	public abstract void removeMember(int memberId) throws ObjectNotFound;

	@Override
    public boolean equals(Object other) {
		if (!(other instanceof Collection<?>)) return false;
		Collection<?> otherColl = (Collection<?>)other;
    	boolean same = mName.equals(otherColl.getName()) && size() == otherColl.size();
    	if (!same) return false;
		for (Iterator<E> i = getMembers().list.iterator(); i.hasNext();) {
			try {
				E thisMem = i.next();
				CollectionMember otherMem = otherColl.getMember(thisMem.getID());
				if (!thisMem.equals(otherMem)) return false;
			} catch (ObjectNotFound ex) {
				return false;
			}
		}
		return true;
    }

	
}