/*******************************************************************************
 * Copyright (c) 2004, 2012 QNX Software Systems 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:
 * QNX Software Systems - Initial API and implementation
 * Nokia - adapt to new command framework
 *******************************************************************************/
package org.eclipse.cdt.debug.internal.ui.actions;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.cdt.debug.core.model.ICastToType;
import org.eclipse.cdt.debug.internal.ui.CDebugImages;
import org.eclipse.cdt.debug.ui.CDebugUIPlugin;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.expressions.IEvaluationContext;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.ui.IDebugView;
import org.eclipse.jface.dialogs.IInputValidator;
import org.eclipse.jface.dialogs.InputDialog;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.ISources;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.handlers.HandlerUtil;

/**
 * The delegate of the "Cast To Type" action.
 */
public class CastToTypeActionHandler extends AbstractHandler {

	static protected class CastToTypeInputValidator implements IInputValidator {

		public CastToTypeInputValidator() {
		}

		@Override
		public String isValid(String newText) {
			if (newText.trim().length() == 0) {
				return ActionMessages.getString("CastToTypeActionDelegate.0"); //$NON-NLS-1$
			}
			return null;
		}
	}

	protected class CastToTypeDialog extends InputDialog {

		public CastToTypeDialog(Shell parentShell, String initialValue) {
			super(parentShell, ActionMessages.getString("CastToTypeActionDelegate.1"), //$NON-NLS-1$
					ActionMessages.getString("CastToTypeActionDelegate.2"), //$NON-NLS-1$
					initialValue, new CastToTypeInputValidator());
		}

		/*
		 * (non-Javadoc)
		 *
		 * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)
		 */
		@Override
		protected void configureShell(Shell shell) {
			super.configureShell(shell);
			shell.setImage(CDebugImages.get(CDebugImages.IMG_LCL_CAST_TO_TYPE));
		}
	}

	private ICastToType[] fCastableItems = new ICastToType[0];

	private IStatus fStatus = null;

	private IWorkbenchPart fTargetPart;

	public CastToTypeActionHandler() {
		super();
	}

	@Override
	public Object execute(ExecutionEvent event) throws ExecutionException {
		fTargetPart = HandlerUtil.getActivePartChecked(event);

		if (getCastToType() == null || getCastToType().length == 0)
			return null;

		BusyIndicator.showWhile(Display.getCurrent(), () -> {
			try {
				doAction(getCastToType());
				setStatus(null);
			} catch (DebugException e) {
				setStatus(e.getStatus());
			}
		});
		if (getStatus() != null && !getStatus().isOK()) {
			IWorkbenchWindow window = CDebugUIPlugin.getActiveWorkbenchWindow();
			if (window != null) {
				CDebugUIPlugin.errorDialog(ActionMessages.getString("CastToTypeActionDelegate.3"), getStatus()); //$NON-NLS-1$
			} else {
				CDebugUIPlugin.log(getStatus());
			}
		}

		return null;
	}

	@Override
	public void setEnabled(Object evaluationContext) {
		ICastToType[] castableItems = getCastToType(evaluationContext);
		setBaseEnabled(castableItems.length > 0);
		setCastToType(castableItems);
	}

	private ICastToType[] getCastToType(Object evaluationContext) {
		List<ICastToType> castableItems = new ArrayList<>();
		if (evaluationContext instanceof IEvaluationContext) {
			Object s = ((IEvaluationContext) evaluationContext).getVariable(ISources.ACTIVE_MENU_SELECTION_NAME);
			if (s instanceof IStructuredSelection) {
				Iterator<?> iter = ((IStructuredSelection) s).iterator();
				while (iter.hasNext()) {
					Object element = DebugPlugin.getAdapter(iter.next(), ICastToType.class);
					if (element instanceof ICastToType) {
						if (((ICastToType) element).canCast()) {
							castableItems.add((ICastToType) element);
						}
					}
				}
			}
		}
		return castableItems.toArray(new ICastToType[castableItems.size()]);
	}

	protected ICastToType[] getCastToType() {
		return fCastableItems;
	}

	protected void setCastToType(ICastToType[] castableItems) {
		fCastableItems = castableItems;
	}

	public IStatus getStatus() {
		return fStatus;
	}

	public void setStatus(IStatus status) {
		fStatus = status;
	}

	protected void doAction(ICastToType[] castableItems) throws DebugException {
		String currentType = castableItems[0].getCurrentType().trim();
		CastToTypeDialog dialog = new CastToTypeDialog(CDebugUIPlugin.getActiveWorkbenchShell(), currentType);
		if (dialog.open() == Window.OK) {
			String newType = dialog.getValue().trim();
			for (ICastToType castableItem : castableItems) {
				castableItem.cast(newType);
			}
			if (getSelectionProvider() != null)
				getSelectionProvider().setSelection(new StructuredSelection(castableItems));
		}
	}

	private ISelectionProvider getSelectionProvider() {
		return (fTargetPart instanceof IDebugView) ? ((IDebugView) fTargetPart).getViewer() : null;
	}
}
