package org.gcube.portlets.user.geoportaldataviewer.client.ui.dandd;

import org.gcube.portlets.user.geoportaldataviewer.client.events.DoActionOnDetailLayersEvent;
import org.gcube.portlets.user.geoportaldataviewer.client.events.DoActionOnDetailLayersEvent.DO_LAYER_ACTION;
import org.gcube.portlets.user.geoportaldataviewer.shared.gis.LayerItem;

import com.github.gwtbootstrap.client.ui.Button;
import com.github.gwtbootstrap.client.ui.CheckBox;
import com.github.gwtbootstrap.client.ui.constants.IconType;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.DragLeaveEvent;
import com.google.gwt.event.dom.client.DragLeaveHandler;
import com.google.gwt.event.dom.client.DragOverEvent;
import com.google.gwt.event.dom.client.DragOverHandler;
import com.google.gwt.event.dom.client.DragStartEvent;
import com.google.gwt.event.dom.client.DragStartHandler;
import com.google.gwt.event.dom.client.DropEvent;
import com.google.gwt.event.dom.client.DropHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.Widget;

public class DragDropLayer extends FlowPanel {

	private static DragDropLayer dragging = null;
	private static DragDropLayer draggingTarget = null;
	final boolean droppable;
	private Label label;
	private CheckBox checkBoxVisibility = new CheckBox();
	private Button button = new Button();
	private HandlerManager applicationBus;

	public DragDropLayer(HandlerManager applicationBus, LayerItem layer, boolean draggable, boolean droppable) {
		this.applicationBus = applicationBus;
		this.label = new Label(layer.getName());

		getElement().getStyle().setMarginTop(5, Unit.PX);
		getElement().getStyle().setMarginBottom(10, Unit.PX);

		if (draggable) {
			initDrag();
		}
		if (droppable) {
			initDrop();
		}
		this.droppable = droppable;

		if (droppable) {
			button.addStyleName("droppable");
		} else if (draggable) {
			button.addStyleName("draggable");
		}

		RangeSlider rs = new RangeSlider();
		FlexTable ft = new FlexTable();
		ft.setWidget(0, 0, button);
		checkBoxVisibility.getElement().getStyle().setMarginLeft(10, Unit.PX);
		checkBoxVisibility.setValue(true);
		ft.setWidget(0, 1, checkBoxVisibility);
		ft.setWidget(0, 2, label);
		ft.setWidget(1, 2, new SimplePanel(rs));
		add(ft);
		button.setIcon(IconType.MOVE);

		checkBoxVisibility.addValueChangeHandler(new ValueChangeHandler<Boolean>() {

			@Override
			public void onValueChange(ValueChangeEvent<Boolean> event) {
				DoActionOnDetailLayersEvent dae = new DoActionOnDetailLayersEvent(DO_LAYER_ACTION.VISIBILITY, layer, null);
				dae.setVisibility(checkBoxVisibility.getValue());
				applicationBus.fireEvent(dae);

			}
		});
	}

	private void initDrag() {
		button.getElement().setDraggable(Element.DRAGGABLE_TRUE);

		addDomHandler(new DragStartHandler() {

			@Override
			public void onDragStart(DragStartEvent event) {
				dragging = DragDropLayer.this;
				event.setData("ID", "UniqueIdentifier");
				event.getDataTransfer().setDragImage(getElement(), 10, 10);

			}
		}, DragStartEvent.getType());
	}

	private void initDrop() {

		addDomHandler(new DragOverHandler() {
			@Override
			public void onDragOver(DragOverEvent event) {
				button.addStyleName("dropping-over");
				GWT.log("drag over");
				draggingTarget = (DragDropLayer) event.getSource();
			}
		}, DragOverEvent.getType());

		addDomHandler(new DragLeaveHandler() {
			@Override
			public void onDragLeave(DragLeaveEvent event) {
				button.removeStyleName("dropping-over");
				GWT.log("drag leave");
				// draggingTarget = (DragDropLayer) event.getSource();
			}
		}, DragLeaveEvent.getType());

		addDomHandler(new DropHandler() {
			@Override
			public void onDrop(DropEvent event) {
				event.preventDefault();
				Object dropTarget = event.getSource();
				GWT.log("on drop");
				button.removeStyleName("dropping-over");
				if (dragging != null) {
					Widget target = null;
					Widget source = null;
					FlowPanel tree = (FlowPanel) DragDropLayer.this.getParent();

					source = dragging;
					int sourceIndex = tree.getWidgetIndex(source);
					int targetIndex = tree.getWidgetIndex(draggingTarget);
					GWT.log("sourceIndex: " + sourceIndex);
					GWT.log("targetIndex: " + targetIndex);
					if (sourceIndex != targetIndex && targetIndex > 0) {
						tree.remove(source);
						target = tree;

						if (source != null && target != null) {
							tree.insert(source, targetIndex);
							// target.setState(true);
						}
						dragging = null;
					}
				}
			}
		}, DropEvent.getType());
	}

}