/*******************************************************************************
 * Copyright (c) 2005, 2017 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 implementation
 *******************************************************************************/
package org.eclipse.debug.internal.ui.views.variables;

import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILogicalStructureType;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.model.IVariable;
import org.eclipse.debug.internal.ui.DebugUIPlugin;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.dialogs.PreferencesUtil;

/**
 * Action which prompts the user to edit the logical structure that
 * is currently active on the given object.
 */
public class EditVariableLogicalStructureAction extends Action {

    /**
     * The editable structure for the currently selected variable or
     * <code>null</code> if none.
     */
	private ILogicalStructureType fStructure = null;
	private VariablesView fView = null;

	public EditVariableLogicalStructureAction(VariablesView view) {
		super();
		fView = view;
		ISelection selection = view.getViewer().getSelection();
		if (selection != null) {
			init(selection);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see
	 * org.eclipse.ui.IObjectActionDelegate#setActivePart(org.eclipse.jface.
	 * action.IAction, org.eclipse.ui.IWorkbenchPart)
	 */
	public void setActivePart(IAction action, IWorkbenchPart targetPart) {
    }

    /**
     * Prompt the user to edit the logical structure associated with the currently
     * selected variable.
     */
	@Override
	public void run() {
		PreferencesUtil.createPreferenceDialogOn(DebugUIPlugin.getShell(), "org.eclipse.jdt.debug.ui.JavaLogicalStructuresPreferencePage", //$NON-NLS-1$
				new String[] { "org.eclipse.jdt.debug.ui.JavaDetailFormattersPreferencePage", //$NON-NLS-1$
						"org.eclipse.jdt.debug.ui.JavaLogicalStructuresPreferencePage", //$NON-NLS-1$
						"org.eclipse.jdt.debug.ui.heapWalking", //$NON-NLS-1$
						"org.eclipse.jdt.debug.ui.JavaPrimitivesPreferencePage" }, (fStructure != null) //$NON-NLS-1$
								? fStructure.getId() + fStructure.getDescription() + fStructure.hashCode()
								: null).open();
    }

	private void init(ISelection selection) {
        fStructure= null;
        Object element = ((IStructuredSelection) selection).getFirstElement();
        if (element instanceof IVariable) {
            try {
                IValue value= ((IVariable) element).getValue();
                ILogicalStructureType type= getLogicalStructure(value);
				fStructure = type;
            } catch (DebugException e) {
				DebugUIPlugin.log(e.getStatus());
            }
        }
		setEnabled(fView.isShowLogicalStructure());
    }

    /**
     * Returns the logical structure currently associated with the given
     * value or <code>null</code> if none.
     * @param value the value
     * @return the logical structure currently associated with the given
     *  value or <code>null</code> if none.
     */
	private ILogicalStructureType getLogicalStructure(IValue value) {
        // This code is based on VariablesViewContentProvider#getLogicalValue(IValue)
        ILogicalStructureType type = null;
        ILogicalStructureType[] types = DebugPlugin.getLogicalStructureTypes(value);
        if (types.length > 0) {
            type= DebugPlugin.getDefaultStructureType(types);
        }
        return type;
    }
}