package org.drools.workflow.core.node;



/*

 * Copyright 2005 JBoss Inc

 * 

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 * 

 *      http://www.apache.org/licenses/LICENSE-2.0

 * 

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



import java.util.List;



import org.drools.definition.process.Connection;

import org.drools.workflow.core.impl.NodeImpl;



/**

 * Default implementation of a join.

 * 

 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>

 */

public class Join extends NodeImpl {



    public static final int TYPE_UNDEFINED     = 0;

    /**

     * The outgoing connection of a join of this type is triggered

     * when all its incoming connections have been triggered.

     */

    public static final int TYPE_AND           = 1;

    /**

     * The outgoing connection of a join of this type is triggered

     * when one of its incoming connections has been triggered.

     */

    public static final int TYPE_XOR           = 2;

    /**

     * The outgoing connection of a join of this type is triggered

     * when one of its incoming connections has been triggered. It then

     * waits until all other incoming connections have been triggered

     * before allowing 

     */

    public static final int TYPE_DISCRIMINATOR = 3;

    

    private static final long serialVersionUID = 400L;



    private int               type;



    public Join() {

        this.type = TYPE_UNDEFINED;

    }



    public void setType(final int type) {

        this.type = type;

    }



    public int getType() {

        return this.type;

    }



    public Connection getTo() {

        final List<Connection> list =

            getOutgoingConnections(org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE);

        if (list.size() > 0) {

            return (Connection) list.get(0);

        }

        return null;

    }

    

    public List<Connection> getDefaultIncomingConnections() {

        return getIncomingConnections(org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE);

    }



    public void validateAddIncomingConnection(final String type,

            final Connection connection) {

        super.validateAddIncomingConnection(type, connection);

        if (!org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE.equals(type)) {

            throw new IllegalArgumentException(

                "This type of node only accepts default incoming connection type!");

        }

    }



    public void validateAddOutgoingConnection(final String type, final Connection connection) {

        super.validateAddOutgoingConnection(type, connection);

        if (!org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE.equals(type)) {

            throw new IllegalArgumentException(

                "This type of node only accepts default outgoing connection type!");

        }

        if (!getOutgoingConnections(org.drools.workflow.core.Node.CONNECTION_DEFAULT_TYPE).isEmpty()) {

            throw new IllegalArgumentException(

                "This type of node cannot have more than one outgoing connection");

        }

    }

    

}