/*******************************************************************************
 * Copyright (c) 2019 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:
 *     Semantum Oy - initial API and implementation
 *******************************************************************************/
package org.simantics.document.swt.core.widget;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.ui.IWorkbenchSite;
import org.simantics.Simantics;
import org.simantics.browsing.ui.Column;
import org.simantics.browsing.ui.Column.Align;
import org.simantics.browsing.ui.StatePersistor;
import org.simantics.browsing.ui.swt.InputSourceImpl;
import org.simantics.browsing.ui.swt.widgets.DragSourceListenerFactory;
import org.simantics.browsing.ui.swt.widgets.ModelBrowser;
import org.simantics.browsing.ui.swt.widgets.impl.WidgetSupportImpl;
import org.simantics.db.layer0.variable.VariableBean;
import org.simantics.db.management.ISessionContext;
import org.simantics.document.server.IEventCommand;
import org.simantics.document.server.JSONObject;
import org.simantics.document.server.bean.Command;
import org.simantics.document.server.client.CommandManager;
import org.simantics.document.server.client.WidgetData;
import org.simantics.document.server.handler.AbstractEventHandler;
import org.simantics.document.server.io.CommandContext;
import org.simantics.document.server.io.CommandContextImpl;
import org.simantics.document.server.io.CommandContextMutable;
import org.simantics.document.server.io.ICommand;
import org.simantics.document.server.io.JSONObjectUtils;
import org.simantics.document.swt.core.SWTDocument;
import org.simantics.document.swt.core.SWTViews;
import org.simantics.document.swt.core.base.LeafWidgetManager;
import org.simantics.document.swt.core.base.PostEventCommand;
import org.simantics.document.swt.core.base.WidgetContainer;
import org.simantics.document.swt.core.bean.ColumnBean;
import org.simantics.document.swt.core.bean.ColumnsBean;
import org.simantics.scl.runtime.function.Function1;
import org.simantics.scl.runtime.function.Function2;
import org.simantics.ui.selection.WorkbenchSelectionUtils;
import org.simantics.utils.datastructures.Pair;

public class Explorer extends LeafWidgetManager<ModelBrowser> {

	@Override
	protected void doUpdateProperties(SWTDocument document, ModelBrowser control, JSONObject object) {
		//			String text = object.getField("text");
		//			control.setText(text);
	}

	protected Column[] getColumns(ColumnsBean bean) {
		Column[] result = new Column[bean.columns.length];
		for(int i=0;i<bean.columns.length;i++) {
			ColumnBean cb = bean.columns[i];
			result[i] = new Column(cb.key, cb.label, Align.valueOf(cb.alignment), cb.width, cb.tooltip, cb.grab, cb.weight);
		}
		return result;
	}

	@Override
	protected ModelBrowser doCreateControl(SWTDocument document, Composite parent, JSONObject object) {

		String browseContext = object.getJSONField("browseContext");
		if(browseContext == null) return null;

		String contextMenuId = object.getJSONField("contextMenuId");

		Boolean displayFilter = object.getJSONField("displayFilter");
		Boolean displayHeader = object.getJSONField("displayHeader");
		Integer style = object.getJSONField("style");
		if(style == null) style = SWT.FULL_SELECTION;

        Boolean vscroll = object.getJSONFieldDefault("VScroll", false);
        if(Boolean.TRUE.equals(vscroll))
            style |= SWT.V_SCROLL;

        Boolean hscroll = object.getJSONFieldDefault("HScroll", false);
        if(Boolean.TRUE.equals(hscroll))
            style |= SWT.H_SCROLL;

        Boolean noscroll = object.getJSONFieldDefault("NoScroll", false);
        if(Boolean.TRUE.equals(noscroll))
            style |= SWT.NO_SCROLL;

        Boolean check = object.getJSONFieldDefault("Check", false);
        if(Boolean.TRUE.equals(check))
            style |= SWT.CHECK;

		StatePersistor persistor = object.getJSONField("persistor");
		final Function1<Object, Boolean> selectionListener = object.getJSONField("selectionListener");

		final Function2<Object, Boolean, Boolean> checkStateListener = object.getJSONField("checkStateListener");

		DragSourceListenerFactory dragSourceListenerFactory = object.getJSONField("dragSourceListenerFactory");

		final IWorkbenchSite site = document.getSite();
		final ISelectionProvider selectionProvider = document.getSelectionProvider();

		Map<String, Object> args = new HashMap<String, Object>();
		args.put("displaySelectors", Boolean.FALSE);
		args.put("displayFilter", displayFilter != null ? displayFilter : Boolean.FALSE);

//		GridLayoutFactory.fillDefaults().applyTo(parent);

		ColumnsBean columns = object.getBeanJSONFieldDefault("columns", ColumnsBean.BINDING, null);
		String editingColumn = object.getJSONFieldDefault("editingColumn", null);

//		Column[] COLUMNS = new Column[] {
//				new Column("HasDisplayProperty", "Parameter description", Align.LEFT, 80, "Input parameter name", true),
//				new Column("HasDisplayValue", "Value", Align.RIGHT, 65, "Value"),
//				new Column("HasDisplayUnit", "Unit", Align.RIGHT, 100, "Unit") 
//		};

//		parent.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_RED));

		final ModelBrowser control = new ModelBrowser(Collections.singleton(browseContext), args, site, parent, new WidgetSupportImpl(), style);

		Tree tree = control.getExplorerControl();
		tree.addListener(SWT.SetData, new Listener() {

			@Override
			public void handleEvent(Event event) {
				SWTViews.notifyScrolledComposite(control);
			}

		});

		if(columns != null)
			control.setColumns(getColumns(columns));
		if(editingColumn != null)
			control.setEditingColumn(editingColumn);
		if(contextMenuId != null)
			control.setContextMenuId(contextMenuId);
		if(dragSourceListenerFactory != null)
			control.setDragSourceListenerFactory(dragSourceListenerFactory);
		if(displayHeader != null)
			tree.setHeaderVisible(displayHeader);

		control.setStatePersistor(persistor);

		control.finish();

		control.setInputSource(new InputSourceImpl<Object>() {

			@Override
			public Object get(ISessionContext ctx, Object selection) {
				return selection;
			}

		});

		// TODO: fixme!
		Object i = object.getJSONField("explorerInput");
		if(i instanceof VariableBean) {
			control.setInput(Simantics.getSessionContext(), ((VariableBean)i).getVariable());
		} else {
			control.setInput(Simantics.getSessionContext(), i);
		}

		control.addListenerToControl(SWT.Selection, new Listener() {

			@Override
			public void handleEvent(Event event) {

				switch (event.type) {
				case SWT.Selection:
					if (event.detail == SWT.CHECK && event.item != null) {
						TreeItem item = (TreeItem) event.item;
						boolean checked = item.getChecked();
						if(checkStateListener != null)
							selectionListener.apply(event);
					}
					break;
				}

				if(selectionListener != null)
					selectionListener.apply(event);

				ISelection selection = (ISelection)control.getExplorer().getWidgetSelection();

				// TODO: refactor this!

				if(selectionProvider != null) {
					selectionProvider.setSelection(selection);
				}

//				if (site != null) {
//					ISelectionProvider sp = site.getSelectionProvider();
//					if (sp != null) {
//						sp.setSelection(selection);
//					}
//				}

			}

		});

		return control;

	}

	@Override
	public String getProperty(SWTDocument document, JSONObject object, WidgetContainer<ModelBrowser> widget, String property) {
	    if("selection".equals(property)) {
            ISelection selection = (ISelection)widget.getControl().getExplorer().getWidgetSelection();
            return SWTViews.encode(object, property, WorkbenchSelectionUtils.getWorkbenchSelectionElements(selection));
	    }
	    return null;
	}

    public static class ExplorerCommandManager implements CommandManager<SWTDocument, WidgetContainer<ModelBrowser>> {

        @Override
        public Collection<Object> updateCommandListeners(final SWTDocument document, final JSONObject object,
                WidgetContainer<ModelBrowser> container) {

            WidgetData wd = document.getWidget(JSONObjectUtils.getId(object));
            List<ICommand> commands = object.getJSONField("commands");
            HashSet<Object> listeners = new HashSet<Object>();
            List<Pair<WidgetData, ICommand>> data = new ArrayList<>();
            data.addAll(SWTViews.getTriggeredCommands(document, commands, "eventOut"));
            data.add(new Pair<WidgetData, ICommand>(wd, new Command("onCheck")));
            Listener listener = new ExplorerListener(wd, data);
            ModelBrowser browser = container.getControl();
            if(!browser.isDisposed()) {
                browser.addListenerToControl(SWT.Selection, listener);
                listeners.add(listener);
            }

            return listeners;

        }

        @Override
        public void removeListener(WidgetContainer<ModelBrowser> container, Object listener) {
            if(container.getControl().isDisposed()) return;
            if(listener instanceof ExplorerListener)
                container.getControl().removeListenerFromControl(SWT.Selection, (Listener)listener);
        }

    }

    @Override
    public IEventCommand eventCommand(SWTDocument document, JSONObject object, WidgetContainer widget, ICommand command, CommandContext p) {
        if("onCheck".equals(command.getCommand())) {
            CommandContextMutable context = new CommandContextImpl().merge(p);
            AbstractEventHandler onCheck = object.getJSONField("onCheck");
            return new PostEventCommand(document, onCheck, context);
        }
        return null;
    }

}