/*******************************************************************************
 * Copyright (c) 2006, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.internal.ui;

import java.util.Arrays;
import java.util.List;

import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.viewers.CheckStateChangedEvent;
import org.eclipse.jface.viewers.CheckboxTableViewer;
import org.eclipse.jface.viewers.ICheckStateListener;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;

/**
 * This class provides selection dialog using a check box table viewer.
 *
 * @since 3.4
 */
public abstract class AbstractDebugCheckboxSelectionDialog extends AbstractDebugSelectionDialog {

	/**
	 * Whether to add Select All / De-select All buttons to the custom footer controls.
	 */
	private boolean fShowSelectButtons = false;

	/**
	 * Constructor
	 * @param parentShell the parent shell
	 */
	public AbstractDebugCheckboxSelectionDialog(Shell parentShell) {
		super(parentShell);
		setShellStyle(getShellStyle() | SWT.RESIZE);
	}

	/**
	 * Returns the viewer cast to the correct instance.  Possibly <code>null</code> if
	 * the viewer has not been created yet.
	 * @return the viewer cast to CheckboxTableViewer
	 */
	protected CheckboxTableViewer getCheckBoxTableViewer() {
		return (CheckboxTableViewer) fViewer;
	}

	@Override
	protected void initializeControls() {
		List<?> selectedElements = getInitialElementSelections();
		if (selectedElements != null && !selectedElements.isEmpty()){
			getCheckBoxTableViewer().setCheckedElements(selectedElements.toArray());
			getCheckBoxTableViewer().setSelection(StructuredSelection.EMPTY);
		}
		super.initializeControls();
	}

	@Override
	protected StructuredViewer createViewer(Composite parent){
		//by default return a checkbox table viewer
		Table table = new Table(parent, SWT.BORDER | SWT.SINGLE | SWT.CHECK);
		GridData gd = new GridData(GridData.FILL_BOTH);
		gd.heightHint = 150;
		gd.widthHint = 250;
		table.setLayoutData(gd);
		return new CheckboxTableViewer(table);
	}

	@Override
	protected void addViewerListeners(StructuredViewer viewer) {
		getCheckBoxTableViewer().addCheckStateListener(new DefaultCheckboxListener());
	}

	/**
	 * A checkbox state listener that ensures that exactly one element is checked
	 * and enables the OK button when this is the case.
	 *
	 */
	private class DefaultCheckboxListener implements ICheckStateListener{
		@Override
		public void checkStateChanged(CheckStateChangedEvent event) {
			getButton(IDialogConstants.OK_ID).setEnabled(isValid());
		}
	}

	@Override
	protected boolean isValid() {
		return getCheckBoxTableViewer().getCheckedElements().length > 0;
	}

	@Override
	protected void okPressed() {
		Object[] elements =  getCheckBoxTableViewer().getCheckedElements();
		setResult(Arrays.asList(elements));
		super.okPressed();
	}

	@Override
	protected void addCustomFooterControls(Composite parent) {
		if (fShowSelectButtons){
			Composite comp = SWTFactory.createComposite(parent, 2, 1, GridData.FILL_HORIZONTAL);
			GridData gd = (GridData) comp.getLayoutData();
			gd.horizontalAlignment = SWT.END;
			Button button = SWTFactory.createPushButton(comp, DebugUIMessages.AbstractDebugCheckboxSelectionDialog_0, null);
			button.addSelectionListener(new SelectionAdapter() {
				@Override
				public void widgetSelected(SelectionEvent e) {
					getCheckBoxTableViewer().setAllChecked(true);
					getButton(IDialogConstants.OK_ID).setEnabled(isValid());
				}
			});
			button = SWTFactory.createPushButton(comp, DebugUIMessages.AbstractDebugCheckboxSelectionDialog_1, null);
			button.addSelectionListener(new SelectionAdapter() {
				@Override
				public void widgetSelected(SelectionEvent e) {
					getCheckBoxTableViewer().setAllChecked(false);
					getButton(IDialogConstants.OK_ID).setEnabled(isValid());
				}
			});
		}
	}

	/**
	 * If this setting is set to true before the dialog is opened, a Select All and
	 * a De-select All button will be added to the custom footer controls.  The default
	 * setting is false.
	 *
	 * @param setting whether to show the select all and de-select all buttons
	 */
	protected void setShowSelectAllButtons(boolean setting){
		fShowSelectButtons = setting;
	}

}