/*******************************************************************************
 * Copyright (c) 2003, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.j2ee.internal.actions;


import java.util.Iterator;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.wizard.Wizard;
import org.eclipse.jface.wizard.WizardDialog;
import org.eclipse.jst.j2ee.internal.plugin.J2EEUIMessages;
import org.eclipse.jst.j2ee.internal.plugin.J2EEUIPlugin;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.IWorkbenchWizard;
import org.eclipse.ui.activities.WorkbenchActivityHelper;


public abstract class AbstractOpenWizardAction extends org.eclipse.jface.action.Action {
	// //$NON-NLS-1$

	private IWorkbench fWorkbench;

	private Class[] fActivatedOnTypes;

	private boolean fAcceptEmptySelection;

	protected AbstractOpenWizardAction() {
		//Default constructor
	}

	public AbstractOpenWizardAction(IWorkbench workbench, String label, Class[] activatedOnTypes, boolean acceptEmptySelection) {
		super(label);
		fWorkbench = workbench;
		fActivatedOnTypes = activatedOnTypes;
		fAcceptEmptySelection = acceptEmptySelection;
	}

	public AbstractOpenWizardAction(IWorkbench workbench, String label, boolean acceptEmptySelection) {
		this(workbench, label, null, acceptEmptySelection);
	}

	public boolean canActionBeAdded() {
		ISelection selection = getCurrentSelection();
		if (selection == null || selection.isEmpty()) {
			return fAcceptEmptySelection;
		}
		if (fActivatedOnTypes != null) {
			if (selection instanceof IStructuredSelection) {
				return isEnabled(((IStructuredSelection) selection).iterator());
			}
			return false;
		}
		return true;
	}

	/**
	 * Create the specific Wizard (to be implemented by a subclass)
	 */
	abstract protected Wizard createWizard();

	protected IStructuredSelection getCurrentSelection() {
		IWorkbenchWindow window = J2EEUIPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow();
		if (window != null) {
			ISelection selection = window.getSelectionService().getSelection();
			if (selection instanceof IStructuredSelection) {
				return (IStructuredSelection) selection;
			}

		}
		return null;
	}

	protected IWorkbench getWorkbench() {
		return fWorkbench;
	}

	private boolean isEnabled(Iterator iter) {
		while (iter.hasNext()) {
			Object obj = iter.next();
			if (!isOfAcceptedType(obj) || !shouldAcceptElement(obj)) {
				return false;
			}
		}
		return true;
	}

	private boolean isOfAcceptedType(Object obj) {
		for (int i = 0; i < fActivatedOnTypes.length; i++) {
			if (fActivatedOnTypes[i].isInstance(obj)) {
				return true;
			}
		}
		return false;
	}

	protected String getDialogText() {
		return J2EEUIMessages.getResourceString(J2EEUIMessages.NEW_LBL);
	}

	/**
	 * The user has invoked this action.
	 */
	@Override
	public void run() {
		Wizard wizard = createWizard();
		if (wizard instanceof IWorkbenchWizard) {
			IStructuredSelection sel = null;
			if (null != getCurrentSelection())
				sel = getCurrentSelection();
			else
				sel = new StructuredSelection();
			((IWorkbenchWizard) wizard).init(J2EEUIPlugin.getDefault().getWorkbench(), sel);
		}
		if (WorkbenchActivityHelper.allowUseOf(null,wizard)) {
			IWorkbenchWindow window = J2EEUIPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow();
			WizardDialog dialog = new WizardDialog(window.getShell(), wizard);
			dialog.create();
			String text = getDialogText();
			if (null != text) {
				dialog.getShell().setText(text);
			}
			dialog.open();
		}
	}

	protected void setWorkbench(IWorkbench workbench) {
		fWorkbench = workbench;
	}

	/**
	 * can be overridden to add more checks obj is guaranteed to be instance of one of the accepted
	 * types
	 */
	protected boolean shouldAcceptElement(Object obj) {
		return true;
	}
}