/*
 * Copyright (C) 2005-2010 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco 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.
 *
 * Alfresco 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 Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.repo.version.common;

import java.io.Serializable;
import java.util.Collection;
import java.util.Map;
import java.util.Set;

import org.alfresco.repo.policy.ClassPolicyDelegate;
import org.alfresco.repo.policy.PolicyComponent;
import org.alfresco.repo.policy.PolicyScope;
import org.alfresco.repo.version.VersionServicePolicies;
import org.alfresco.repo.version.VersionServicePolicies.AfterCreateVersionPolicy;
import org.alfresco.repo.version.VersionServicePolicies.BeforeCreateVersionPolicy;
import org.alfresco.repo.version.VersionServicePolicies.CalculateVersionLabelPolicy;
import org.alfresco.repo.version.VersionServicePolicies.OnCreateVersionPolicy;
import org.alfresco.repo.version.common.versionlabel.SerialVersionLabelPolicy;
import org.alfresco.service.cmr.dictionary.DictionaryService;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.service.cmr.repository.NodeService;
import org.alfresco.service.cmr.repository.StoreRef;
import org.alfresco.service.cmr.version.Version;
import org.alfresco.service.cmr.version.VersionServiceException;
import org.alfresco.service.namespace.QName;

/**
 * Abstract version service implementation.
 * 
 * @author Roy Wetherall
 */
public abstract class AbstractVersionServiceImpl 
{    
	/**
     * The common node service
     */
    protected NodeService nodeService ;
	
    /**
     * Policy component
     */
	protected PolicyComponent policyComponent;
	
	/**
     * The dictionary service
     */
    protected DictionaryService dictionaryService;
	
	/**
	 * Policy delegates
	 */
	private ClassPolicyDelegate<BeforeCreateVersionPolicy> beforeCreateVersionDelegate;
	private ClassPolicyDelegate<AfterCreateVersionPolicy> afterCreateVersionDelegate;
	private ClassPolicyDelegate<OnCreateVersionPolicy> onCreateVersionDelegate;
	private ClassPolicyDelegate<CalculateVersionLabelPolicy> calculateVersionLabelDelegate;
    
	/**
     * Sets the general node service
     * 
     * @param nodeService   the node service
     */
    public void setNodeService(NodeService nodeService)
    {
        this.nodeService = nodeService;
    }
	
	/**
	 * Sets the policy component
	 * 
	 * @param policyComponent  the policy component
	 */
    public void setPolicyComponent(PolicyComponent policyComponent) 
	{
		this.policyComponent = policyComponent;
	}
	    
    /**
     * Sets the dictionary service
     * 
     * @param dictionaryService  the dictionary service
     */
    public void setDictionaryService(DictionaryService dictionaryService)
    {
        this.dictionaryService = dictionaryService;
    }
	
	/**
	 * Initialise method
	 */
	public void initialise()
    {
		// Register the policies
        this.beforeCreateVersionDelegate = this.policyComponent.registerClassPolicy(VersionServicePolicies.BeforeCreateVersionPolicy.class);
        this.afterCreateVersionDelegate = this.policyComponent.registerClassPolicy(VersionServicePolicies.AfterCreateVersionPolicy.class);
		this.onCreateVersionDelegate = this.policyComponent.registerClassPolicy(VersionServicePolicies.OnCreateVersionPolicy.class);
		this.calculateVersionLabelDelegate = this.policyComponent.registerClassPolicy(VersionServicePolicies.CalculateVersionLabelPolicy.class);		
    }	
	
	/**
	 * Invokes the before create version policy behaviour
	 * 
	 * @param nodeRef  the node being versioned
	 */
	protected void invokeBeforeCreateVersion(NodeRef nodeRef)
	{
        // invoke for node type
        QName nodeTypeQName = nodeService.getType(nodeRef);
        this.beforeCreateVersionDelegate.get(nodeTypeQName).beforeCreateVersion(nodeRef);
        // invoke for node aspects
        Set<QName> nodeAspectQNames = nodeService.getAspects(nodeRef);
		this.beforeCreateVersionDelegate.get(nodeAspectQNames).beforeCreateVersion(nodeRef);
	}
	
	/**
	 * Invoke the after create version policy bahaviour
	 * 
	 * @param nodeRef	the nodeRef versioned
	 * @param version 	the created version
	 */
	protected void invokeAfterCreateVersion(NodeRef nodeRef, Version version)
	{
		// invoke for node type
        QName nodeTypeQName = nodeService.getType(nodeRef);
        this.afterCreateVersionDelegate.get(nodeTypeQName).afterCreateVersion(nodeRef, version);
        // invoke for node aspects
        Set<QName> nodeAspectQNames = nodeService.getAspects(nodeRef);
		this.afterCreateVersionDelegate.get(nodeAspectQNames).afterCreateVersion(nodeRef, version);
	}
	
	/**
	 * Invoke the on create version policy behaviour
	 *
	 */
	protected void invokeOnCreateVersion(
			NodeRef nodeRef, 
			Map<String, Serializable> versionProperties, 
			PolicyScope nodeDetails)
	{
		// Sort out the policies for the node type
		QName classRef = this.nodeService.getType(nodeRef);
		invokeOnCreateVersion(classRef, nodeRef, versionProperties, nodeDetails);
		
		// Sort out the policies for the aspects
		Collection<QName> aspects = this.nodeService.getAspects(nodeRef);
		for (QName aspect : aspects) 
		{
			invokeOnCreateVersion(aspect, nodeRef, versionProperties, nodeDetails);
		}
		
	}
	
	/**
	 * Invokes the on create version policy behaviour for a given type 
	 * 
	 * @param classRef
	 * @param nodeDetails
	 * @param nodeRef
	 * @param versionProperties
	 */
	private void invokeOnCreateVersion(
			QName classRef,
			NodeRef nodeRef,
			Map<String, Serializable> versionProperties,
			PolicyScope nodeDetails)
	{
		Collection<OnCreateVersionPolicy> policies = this.onCreateVersionDelegate.getList(classRef);
		if (policies.size() == 0)
		{
			// Call the default implementation
			defaultOnCreateVersion(
					classRef,
					nodeRef,
					versionProperties,
					nodeDetails);
		}
		else
		{
			// Call the policy definitions
			for (VersionServicePolicies.OnCreateVersionPolicy policy : policies) 
			{
				policy.onCreateVersion(
						classRef,
						nodeRef,
						versionProperties,
						nodeDetails);
			}
		}
	}
	
	/**
	 * Default implementation of the on create version policy.  Called if no behaviour is registered for the 
	 * policy for the specified type.
	 * 
	 * @param nodeRef
	 * @param versionProperties
	 * @param nodeDetails
	 */
	abstract protected void defaultOnCreateVersion(
			QName classRef,
			NodeRef nodeRef, 
			Map<String, Serializable> versionProperties, 
			PolicyScope nodeDetails);
	
	/**
	 * Invoke the calculate version label policy behaviour
	 * 
	 * @param classRef
	 * @param preceedingVersion
	 * @param versionNumber
	 * @param versionProperties
	 * @return
	 */
	protected String invokeCalculateVersionLabel(
			QName classRef,
			Version preceedingVersion, 
			int versionNumber, 
			Map<String, Serializable>versionProperties)
	{
		String versionLabel = null;
		
		Collection<CalculateVersionLabelPolicy> behaviours = this.calculateVersionLabelDelegate.getList(classRef);
		if (behaviours.size() == 0)
		{
            // Default the version label to the SerialVersionLabelPolicy
            SerialVersionLabelPolicy defaultVersionLabelPolicy = new SerialVersionLabelPolicy();
            versionLabel = defaultVersionLabelPolicy.calculateVersionLabel(classRef, preceedingVersion, versionNumber, versionProperties);
		}
		else if (behaviours.size() == 1)
		{
			// Call the policy behaviour
			CalculateVersionLabelPolicy[] arr = behaviours.toArray(new CalculateVersionLabelPolicy[]{});
			versionLabel = arr[0].calculateVersionLabel(classRef, preceedingVersion, versionNumber, versionProperties);
		}
		else
		{
			// Error since we can only deal with a single caculate version label policy
			throw new VersionServiceException("More than one CalculateVersionLabelPolicy behaviour has been registered for the type " + classRef.toString());
		}
		
		return versionLabel;
	}
	
    abstract public StoreRef getVersionStoreReference();
}