/*
 *                 Sun Public License Notice
 *
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 *
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */
package org.netbeans.modules.refactoring.api;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import org.netbeans.modules.javacore.internalapi.JavaMetamodel;
import org.netbeans.modules.refactoring.classpath.RefactoringClassPathImplementation;
import org.netbeans.spi.java.classpath.ClassPathFactory;
import org.openide.ErrorManager;
import org.netbeans.modules.javacore.*;
import org.netbeans.modules.javacore.internalapi.ProgressListener;
import org.netbeans.modules.javacore.internalapi.ProgressSupport;
import org.openide.loaders.DataObject;
import org.openide.nodes.Node;
import org.openide.windows.TopComponent;

/** Abstract superclass for API for particular refactorings.
 * Subclasses of this class will typically be stateful classes
 * enforcing the following order of method calls:
 * 

 *  
preCheck
 *  
setParameters (this method will typically be added by the subclass
 *  to allow parametrization of the implemented refactoring)
 *  
prepare
 * 
 *
 * @author Martin Matula
 */
public abstract class AbstractRefactoring {
    /** Pre-check state. */
    public static final int PRE_CHECK = 1;
    /** Parameters check state. */
    public static final int PARAMETERS_CHECK = 2;
    /** Prepare state. */
    public static final int PREPARE = 3;
    
    private ProgressSupport progressSupport;
    /** Perform checks to ensure that the preconditions are met for the implemented
     * refactoring.
     * @return Chain of problems encountered or null if no problems
     * were found.
     */
    public abstract Problem preCheck();
    
    /** Collects and returns a set of refactoring elements - objects that 
     * will be affected by the refactoring.
     * @param elements Collection that the operation will use to return
     * instances of {@link org.netbeans.modules.refactoring.api.RefactoringElement} class representing objects that
     * will be affected by the refactoring.
     * @return Chain of problems encountered or null in no problems
     * were found.
     */
    public abstract Problem prepare(Collection elements);
    
    /** Registers ProgressListener to receive events.
     * @param listener The listener to register.
     *
     */
    public synchronized void addProgressListener(ProgressListener listener) {
        if (progressSupport == null ) {
            progressSupport = new ProgressSupport();
        }
        progressSupport.addProgressListener(listener);
    }
    
    /** Removes ProgressListener from the list of listeners.
     * @param listener The listener to remove.
     *
     */
    public synchronized void removeProgressListener(ProgressListener listener) {
        if (progressSupport != null ) {
            progressSupport.removeProgressListener(listener); 
        }
    }
    
    /** Notifies all registered listeners about the event.
     *
     * @param type Type of operation that is starting.
     * @param count Number of steps the operation consists of.
     *
     */
    protected void fireProgressListenerStart(int type, int count) {
        if (progressSupport != null) 
            progressSupport.fireProgressListenerStart(type, count);
    }
    
    /** Notifies all registered listeners about the event.
     */
    protected void fireProgressListenerStep() {
        if (progressSupport != null)
            progressSupport.fireProgressListenerStep();
    }
    
    /** Notifies all registered listeners about the event.
     */
    protected void fireProgressListenerStop() {
        if (progressSupport != null)
            progressSupport.fireProgressListenerStop();
    }
    
    public abstract void setClassPath();
    
    public abstract void cancelPrepare();
}