/*******************************************************************************
 * Copyright (c) 2010, 2012 Freescale Semiconductor. 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:
 *     Freescale Semiconductor - initial API and implementation
 *     Axel Mueller            - Bug 306555 - Add support for cast to type / view as array (IExpressions2)
 *     Jens Elmenthaler (Verigy) - Added Full GDB pretty-printing support (bug 302121)
 *******************************************************************************/
package org.eclipse.cdt.dsf.gdb.internal.ui.viewmodel;

import org.eclipse.cdt.dsf.concurrent.DsfRunnable;
import org.eclipse.cdt.dsf.concurrent.RequestMonitor;
import org.eclipse.cdt.dsf.debug.internal.ui.viewmodel.DsfCastToTypeSupport;
import org.eclipse.cdt.dsf.debug.service.IExpressions.IExpressionDMContext;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.SyncVariableDataAccess;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.VariableVMNode;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.VariableVMProvider;
import org.eclipse.cdt.dsf.gdb.IGdbDebugPreferenceConstants;
import org.eclipse.cdt.dsf.gdb.internal.ui.GdbUIPlugin;
import org.eclipse.cdt.dsf.gdb.internal.ui.viewmodel.GdbVariableVMNode.IncompleteChildrenVMC;
import org.eclipse.cdt.dsf.service.DsfSession;
import org.eclipse.cdt.dsf.ui.viewmodel.AbstractVMAdapter;
import org.eclipse.cdt.dsf.ui.viewmodel.IRootVMNode;
import org.eclipse.cdt.dsf.ui.viewmodel.IVMNode;
import org.eclipse.cdt.dsf.ui.viewmodel.datamodel.RootDMVMNode;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeSelection;
import org.eclipse.jface.viewers.TreePath;

/**
 * A specialization of VariableVMProvider that uses a GDB-specific variable VM
 * node. To understand why this is necessary, see GdbVariableVMNode.
 */
public class GdbVariableVMProvider extends VariableVMProvider {

	private IPropertyChangeListener fPreferencesListener;

	/**
	 * Constructor (passthru)
	 */
	public GdbVariableVMProvider(AbstractVMAdapter adapter, IPresentationContext context, DsfSession session) {
		super(adapter, context, session);

		final IPreferenceStore store = GdbUIPlugin.getDefault().getPreferenceStore();

		Integer childCountLimit = store
				.getInt(IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS);
		if (childCountLimit != 0) {
			getPresentationContext().setProperty(
					IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS, childCountLimit);
		}

		fPreferencesListener = new IPropertyChangeListener() {
			@Override
			public void propertyChange(final PropertyChangeEvent event) {
				handlePropertyChanged(store, event);
			}
		};
		store.addPropertyChangeListener(fPreferencesListener);
	}

	@Override
	public void dispose() {
		super.dispose();

		final IPreferenceStore store = GdbUIPlugin.getDefault().getPreferenceStore();
		store.removePropertyChangeListener(fPreferencesListener);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.VariableVMProvider#configureLayout(org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.SyncVariableDataAccess)
	 */
	@Override
	protected void configureLayout() {
		// Create the variable data access routines.
		SyncVariableDataAccess varAccess = new SyncVariableDataAccess(getSession());

		// Create the top level node to deal with the root selection.
		IRootVMNode rootNode = new RootDMVMNode(this);
		setRootNode(rootNode);

		// Create the next level which represents members of structs/unions/enums and elements of arrays.
		IVMNode subExpressioNode = new GdbVariableVMNode(this, getSession(), varAccess);
		addChildNodes(rootNode, new IVMNode[] { subExpressioNode });

		/* Wire up the casting support. IExpressions2 service is always available
		 * for gdb. No need to call hookUpCastingSupport */
		((VariableVMNode) subExpressioNode)
				.setCastToTypeSupport(new DsfCastToTypeSupport(getSession(), GdbVariableVMProvider.this, varAccess));

		// Configure the sub-expression node to be a child of itself.  This way the content
		// provider will recursively drill-down the variable hierarchy.
		addChildNodes(subExpressioNode, new IVMNode[] { subExpressioNode });
	}

	@Override
	public void handleEvent(Object event, final RequestMonitor rm) {
		if (event instanceof DoubleClickEvent && !isDisposed()) {

			final ISelection selection = ((DoubleClickEvent) event).getSelection();
			if (selection instanceof IStructuredSelection) {

				Object element = ((IStructuredSelection) selection).getFirstElement();
				if (element instanceof IncompleteChildrenVMC) {

					IncompleteChildrenVMC incompleteChildrenVmc = ((IncompleteChildrenVMC) element);
					IVMNode node = incompleteChildrenVmc.getVMNode();
					if (node instanceof GdbVariableVMNode && node.getVMProvider() == this) {

						if (selection instanceof ITreeSelection) {

							ITreeSelection treeSelection = (ITreeSelection) selection;
							TreePath path = treeSelection.getPaths()[0];
							IExpressionDMContext exprCtx = incompleteChildrenVmc.getParentDMContext();
							((GdbVariableVMNode) node).incrementChildCountLimit(exprCtx);

							// replace double click event with the fetch more children event.
							final FetchMoreChildrenEvent fetchMoreChildrenEvent = new FetchMoreChildrenEvent(exprCtx,
									path);
							getExecutor().execute(new DsfRunnable() {
								@Override
								public void run() {
									handleEvent(fetchMoreChildrenEvent, rm);
								}
							});

							return;
						}
					}
				}
			}
		}

		super.handleEvent(event, rm);
	}

	/**
	 * @param store
	 * @param event
	 *
	 * @since 3.0
	 */
	protected void handlePropertyChanged(final IPreferenceStore store, final PropertyChangeEvent event) {
		String property = event.getProperty();
		if (IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS.equals(property)) {
			Integer childCountLimit = store
					.getInt(IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS);

			if (childCountLimit != 0) {
				getPresentationContext().setProperty(
						IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS, childCountLimit);
			} else {
				getPresentationContext()
						.setProperty(IGdbDebugPreferenceConstants.PREF_INITIAL_CHILD_COUNT_LIMIT_FOR_COLLECTIONS, null);
			}

			getExecutor().execute(new DsfRunnable() {
				@Override
				public void run() {
					handleEvent(event);
				}
			});
		}
	}
}
