/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.motorolamobility.studio.android.db.core.command;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.IHandler;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;

import com.motorola.studio.android.common.log.StudioLogger;
import com.motorolamobility.studio.android.db.core.DbCoreActivator;
import com.motorolamobility.studio.android.db.core.exception.MotodevDbException;
import com.motorolamobility.studio.android.db.core.project.ProjectNode;
import com.motorolamobility.studio.android.db.core.ui.DbNode;
import com.motorolamobility.studio.android.db.core.ui.IDbNode;
import com.motorolamobility.studio.android.db.core.ui.ITreeNode;
import com.motorolamobility.studio.android.db.core.ui.action.CreateDatabaseManagementClassesAction;
import com.motorolamobility.studio.android.db.core.ui.view.MOTODEVDatabaseExplorerView;

/**
 * This class implements the command to create database management classes using an instance of {@link IDbNode} object.
 */
public class CreateDatabaseManagementClassesHandler extends AbstractHandler implements IHandler
{

    private IDbNode selectedDbNode = null;

    private ProjectNode selectedProjectNode;

    private void setSelectedNode()
    {

        this.selectedDbNode = null;

        this.selectedProjectNode = null;

        MOTODEVDatabaseExplorerView view = DbCoreActivator.getMOTODEVDatabaseExplorerView();

        if (view != null)
        {
            // if the Database view is active, looks for the db and project nodes
            ITreeNode items = view.getSelectedItemOnTree();

            if (items != null)
            {

                if (items instanceof IDbNode)
                {

                    this.selectedDbNode = (IDbNode) items;

                }
                else if (items instanceof ProjectNode)
                {
                    this.selectedProjectNode = (ProjectNode) items;
                }
            }
        }
        else
        {
            // looks for the project and db resources at the package explorer view
            IWorkbench workbench = PlatformUI.getWorkbench();

            if ((workbench != null) && !workbench.isClosing())
            {

                IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();

                if (window != null)
                {
                    ISelection selection = window.getSelectionService().getSelection();
                    IStructuredSelection structureSelection = null;
                    if (selection instanceof IStructuredSelection)
                    {
                        structureSelection = (IStructuredSelection) selection;
                    }
                    else
                    {
                        structureSelection = new StructuredSelection();
                    }

                    Object selectionElement = structureSelection.getFirstElement();

                    if (selectionElement != null)
                    {

                        //the wizard was requested from a click on .db file or project
                        IResource resource = null;
                        // in case the item as a resource, retrieve it
                        if (selectionElement instanceof IResource)
                        {
                            resource = (IResource) selectionElement;
                        }

                        else if (selectionElement instanceof IAdaptable)
                        {
                            try
                            {
                                resource =
                                        (IResource) ((IAdaptable) selectionElement)
                                                .getAdapter(IResource.class);
                            }
                            catch (Exception e)
                            {
                                StudioLogger.error(CreateDatabaseManagementClassesAction.class,
                                        e.getMessage());
                            }
                        }

                        if (resource != null)
                        {
                            this.selectedProjectNode = new ProjectNode(resource.getProject(), null);

                            if (resource instanceof IFile)
                            {
                                try
                                {
                                    this.selectedDbNode =
                                            new DbNode(new Path(resource.getLocation().toFile()
                                                    .getAbsolutePath()), this.selectedProjectNode);
                                }
                                catch (MotodevDbException e)
                                {
                                    StudioLogger.error(CreateDatabaseManagementClassesAction.class,
                                            e.getMessage());
                                }
                            }
                        }
                    }

                }
            }
        }
    }

    /**
     *  Constructor when there is NOT a node selected on {@link MOTODEVDatabaseExplorerView}
     */
    public CreateDatabaseManagementClassesHandler()
    {
        setSelectedNode();
    }

    /**
     * Constructor when there is a node selected on {@link MOTODEVDatabaseExplorerView}
     * @param node
     */
    public CreateDatabaseManagementClassesHandler(IDbNode node)
    {
        this.selectedDbNode = node;
    }

    /* (non-Javadoc)
     * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)
     */
    public Object execute(ExecutionEvent event) throws ExecutionException
    {
        CreateDatabaseManagementClassesAction action = new CreateDatabaseManagementClassesAction();
        setSelectedNode();
        action.setDbNodeSelected(selectedDbNode);

        action.setProjectNodeSelected(selectedProjectNode);

        action.run();

        return null;
    }

}