/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * 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:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.modeling.ui.modelBrowser.handlers;

import java.lang.reflect.InvocationTargetException;
import java.util.Set;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.dialogs.ProgressMonitorDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.handlers.HandlerUtil;
import org.simantics.browsing.ui.NodeContext;
import org.simantics.browsing.ui.common.node.DeleteException;
import org.simantics.browsing.ui.common.node.IDeletable;
import org.simantics.browsing.ui.common.node.IDeletableNode;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.exception.CannotRemoveException;
import org.simantics.db.layer0.util.RemoverUtil;
import org.simantics.modeling.ui.Activator;
import org.simantics.modeling.ui.modelBrowser.model.INode;
import org.simantics.modeling.ui.modelBrowser.model.INode2;
import org.simantics.ui.SimanticsUI;
import org.simantics.utils.logging.TimeLogger;
import org.simantics.utils.ui.ErrorLogger;
import org.simantics.utils.ui.ISelectionUtils;
import org.simantics.utils.ui.dialogs.ShowMessage;

/**
 * @author Tuukka Lehtonen
 */
public class DeleteNodeHandler extends AbstractHandler {

    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {
        TimeLogger.resetTimeAndLog(getClass(), "execute");
        
        Shell shell = HandlerUtil.getActiveShellChecked(event);
        ISelection sel = HandlerUtil.getCurrentSelection(event);
        Set<NodeContext> ctxs = ISelectionUtils.filterSetSelection(sel, NodeContext.class);
        if (ctxs.isEmpty())
            return null;

        if (ctxs.size() == 1 && handleLegacyDelete(ctxs.iterator().next())) {
            return null;
        }

        // If all selected nodes are IDeletableNodes, delete them.
        final Set<IDeletableNode> deletableNodes = ISelectionUtils.filterSetSelection(ctxs, IDeletableNode.class);
        if (!deletableNodes.isEmpty()) {
            // Only delete if all selected nodes are IDeletableNodes
            if (deletableNodes.size() == ctxs.size()) {
                inJob(shell, new IRunnableWithProgress() {
                    @Override
                    public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
                        monitor.beginTask("Delete selected nodes", IProgressMonitor.UNKNOWN);
                        try {
                            for (IDeletableNode deletableNode : deletableNodes) {
                                deletableNode.delete();
                            }
                        } catch (DeleteException e) {
                            throw new InvocationTargetException(e);
                        }
                    }
                });
            }
        } else {
            final Set<Resource> rs = ISelectionUtils.filterSetSelection(ctxs, Resource.class);
            if (rs.size() == ctxs.size()) {
                inJob(shell, new IRunnableWithProgress() {
                    @Override
                    public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
                        monitor.beginTask("Delete selected nodes", IProgressMonitor.UNKNOWN);
                        try {
                            RemoverUtil.tryCollectionRemover(rs);
                        } catch (CannotRemoveException e) {
                        	ShowMessage.showInformation("Delete Selection Was Denied", e.getLocalizedMessage());
                        } catch (DatabaseException e) {
                            throw new InvocationTargetException(e);
                        }
                    }
                });
            }
        }

        TimeLogger.log("Node deleted");
        return null;
    }

    private void inJob(Shell shell, final IRunnableWithProgress runnable) {
        ProgressMonitorDialog dialog = new ProgressMonitorDialog(shell);
        try {
            dialog.run(true, false, runnable);
        } catch (InvocationTargetException e) {
            Activator.getDefault().getLog().log( new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Delete failed, see exception for details.", e.getCause()) );
        } catch (InterruptedException e) {
            Activator.getDefault().getLog().log( new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Delete failed, see exception for details.", e.getCause()) );
        }
//        Job job = new Job("Delete selection") {
//            @Override
//            protected IStatus run(IProgressMonitor monitor) {
//                monitor.beginTask("Delete selected nodes", IProgressMonitor.UNKNOWN);
//                try {
//                    runnable.run(monitor);
//                    return Status.OK_STATUS;
//                } catch (InvocationTargetException e) {
//                    return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Delete failed, see exception for details.", e.getCause());
//                } catch (Exception e) {
//                    return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Delete failed, see exception for details.", e);
//                } finally {
//                    monitor.done();
//                }
//            }
//        };
//        job.setUser(true);
//        job.setRule(new ObjectIdentitySchedulingRule(schedulingObject));
//        job.schedule();
    }


    /**
     * @param ctx
     * @return
     */
    private boolean handleLegacyDelete(NodeContext ctx) {
        if (ctx.getAdapter(IDeletable.class) == null) {
            return false;
        }

        final INode node = (INode) ctx.getAdapter(INode.class);
        if (node != null) {
            SimanticsUI.getSession().asyncRequest(new WriteRequest() {
                @Override
                public void perform(WriteGraph graph) throws DatabaseException {
                    node.handleDelete(graph);
                }
            });
            return true;
        }

        INode2 node2 = (INode2) ctx.getAdapter(INode2.class);
        if (node2 != null) {
            try {
                node2.handleDelete();
            } catch (DeleteException e) {
                ShowMessage.showError("Delete failed", e.getMessage());
                ErrorLogger.defaultLogError(e);
            }
            return true;
        }

        // Could not handle with legacy logic.
        return false;
    }

}