//   Copyright 2012 Georg-August-Universität Göttingen, Germany
//
//   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.

package de.ugoe.cs.autoquest.tasktrees.treeifc;

/**
 * <p>
 * Default implementation for a task instance visitor performing a traversal of the instances
 * </p>
 * 
 * @author Patrick Harms
 */
public class DefaultTaskInstanceTraversingVisitor implements ITaskInstanceVisitor {

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(IEventTaskInstance)
     */
    @Override
    public void visit(IEventTaskInstance eventTaskInstance) {
        // do nothing
    }

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(IIterationInstance)
     */
    @Override
    public void visit(IIterationInstance iterationInstance) {
        visit((ITaskInstanceList) iterationInstance);
    }

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(IOptionalInstance)
     */
    @Override
    public void visit(IOptionalInstance optionalInstance) {
        if (optionalInstance.getChild() != null) {
            optionalInstance.getChild().accept(this);
        }
    }

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(ISelectionInstance)
     */
    @Override
    public void visit(ISelectionInstance selectionInstance) {
        selectionInstance.getChild().accept(this);
    }

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(ISequenceInstance)
     */
    @Override
    public void visit(ISequenceInstance sequenceInstance) {
        visit((ITaskInstanceList) sequenceInstance);
    }

    /* (non-Javadoc)
     * @see de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstanceVisitor#visit(ITaskInstance)
     */
    @Override
    public void visit(ITaskInstance taskInstance) {
        if (taskInstance instanceof IEventTaskInstance) {
            visit((IEventTaskInstance) taskInstance);
        }
        else if (taskInstance instanceof IIterationInstance) {
            visit((IIterationInstance) taskInstance);
        }
        else if (taskInstance instanceof IOptionalInstance) {
            visit((IOptionalInstance) taskInstance);
        }
        else if (taskInstance instanceof ISelectionInstance) {
            visit((ISelectionInstance) taskInstance);
        }
        else if (taskInstance instanceof ISequenceInstance) {
            visit((ISequenceInstance) taskInstance);
        }
    }


    /**
     * <p>
     * common implementation for traversing task instance lists.
     * </p>
     * 
     * @param taskInstanceList the task instance list to be traversed
     */
    public void visit(ITaskInstanceList taskInstanceList) {
        for (ITaskInstance child : taskInstanceList) {
            child.accept(this);
        }
    }
}