package org.simantics.district.selection.ui;

import java.util.Collection;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.resource.LocalResourceManager;
import org.eclipse.jface.resource.ResourceManager;
import org.eclipse.jface.viewers.CheckStateChangedEvent;
import org.eclipse.jface.viewers.CheckboxTableViewer;
import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.ICheckStateListener;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TableViewerColumn;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Table;
import org.simantics.Simantics;
import org.simantics.db.ReadGraph;
import org.simantics.db.common.procedure.adapter.SyncListenerAdapter;
import org.simantics.db.exception.DatabaseException;
import org.simantics.district.selection.ElementSelector;
import org.simantics.district.selection.ui.parts.ElementSelectionView;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ElementSelectorTableUI extends Composite {

	private static final Logger LOGGER = LoggerFactory.getLogger(ElementSelectorTableUI.class);

	private CheckboxTableViewer viewer;

	private ElementSelectionView view;

	private ResourceManager resourceManager;

	public ElementSelectorTableUI(Composite parent, int style, ElementSelectionView view) {
		super(parent, style);

		resourceManager = new LocalResourceManager(JFaceResources.getResources(), this);

		this.view = view;

		parent.setLayout(new FillLayout());
		// GridDataFactory.fillDefaults().grab(true, true).applyTo(this);
		// GridLayoutFactory.fillDefaults().numColumns(1).applyTo(this);
		this.setLayout(new FillLayout());

		viewer = createViewer();
		addSelectionListener();
		addCheckStateListener();
		setContentProvider();
		createSelectorListener(parent);
		enableToolTips();
		configureTable();
	}

	private void addCheckStateListener() {
		viewer.addCheckStateListener(new ICheckStateListener() {
			
			@Override
			public void checkStateChanged(CheckStateChangedEvent event) {
				boolean checked = event.getChecked();
				if (checked) {
					view.performSelection(getDisplay(), (ElementSelector) event.getElement());
				} else {
					view.clearResultVisualisation((ElementSelector) event.getElement());
				}
			}
		});
	}

	public Table getTable() {
		return viewer.getTable();
	}

	public ElementSelector getSelectedItem() {
		IStructuredSelection selection = (IStructuredSelection) viewer.getSelection();
		return selection != null ? (ElementSelector) selection.getFirstElement() : null;
	}

	private CheckboxTableViewer createViewer() {
		return CheckboxTableViewer.newCheckList(this, SWT.FULL_SELECTION | SWT.SINGLE);
	}

	private void configureTable() {
		Table table = getTable();
		table.setHeaderVisible(true);
		table.setLinesVisible(true);

		createNameColumn();
		createQueryColumn();
		//createQueryActiveColumn();
	}

	private void enableToolTips() {
		ColumnViewerToolTipSupport.enableFor(viewer);
	}

	private void setContentProvider() {
		viewer.setContentProvider(new IStructuredContentProvider() {
			@Override
			public Object[] getElements(Object inputElement) {
				if (inputElement == null || !(inputElement instanceof Collection))
					return new Object[0];

				return ((Collection<?>) inputElement).toArray();
			}
		});
	}

	private TableViewerColumn createNameColumn() {
		TableViewerColumn column = new TableViewerColumn(viewer, SWT.NONE);
		column.getColumn().setText("Name");
		column.getColumn().setWidth(200);
		column.getColumn().setResizable(true);
		column.setLabelProvider(new ColumnLabelProvider() {
			@Override
			public String getText(Object element) {
				ElementSelector selector = (ElementSelector) element;
				return " " + selector.getName();
			}

			@Override
			public Image getImage(Object element) {
				ElementSelector selector = (ElementSelector) element;
				float[] color = selector.getColor();
				if (color == null)
					return null;

				RGB rgb = ElementSelectionTools.literalToColor(color).getRgb();

				PaletteData paletteData = new PaletteData(new RGB[] { new RGB(255, 255, 255), rgb });

				// Create image with a colored horizontal bar
				// TODO: Indicate line width
				Image image = resourceManager.createImage(ImageDescriptor.createFromImageDataProvider(zoom -> {
					int height = 8 * zoom / 100;
					int width = 40 * zoom / 100;
					ImageData imageData = new ImageData(width, height, 1, paletteData);
					for (int x = 0; x < width; x++) {
						for (int y = 0; y < height; y++) {
							imageData.setPixel(x, y, 1);
						}
					}

					return imageData;
				}));

				return image;
			}
		});
		return column;
	}

	private TableViewerColumn createQueryColumn() {
		TableViewerColumn column = new TableViewerColumn(viewer, SWT.NONE);
		column.getColumn().setText("Query");
		column.getColumn().setWidth(600);
		column.getColumn().setResizable(true);
		column.setLabelProvider(new ColumnLabelProvider() {
			@Override
			public String getText(Object element) {
				ElementSelector selector = (ElementSelector) element;
				return selector.getExpression();
			}
		});
		return column;
	}

	private void createSelectorListener(Composite parent) {
		Simantics.getSession().asyncRequest(new ElementSelectionTools.SelectionsRequest(),
				new SyncListenerAdapter<Collection<ElementSelector>>() {
					public void execute(ReadGraph graph, Collection<ElementSelector> result) {
						parent.getDisplay().asyncExec(() -> {
							viewer.setInput(result);
						});
					}

					@Override
					public void exception(ReadGraph graph, Throwable t) throws DatabaseException {
						LOGGER.error("Error getting element selector list", t);
					}

					@Override
					public boolean isDisposed() {
						return ElementSelectorTableUI.this.isDisposed();
					}
				});
	}

	private void addSelectionListener() {
		viewer.addDoubleClickListener(new DoubleClickListener());
	}

	private final class DoubleClickListener implements IDoubleClickListener {
		@Override
		public void doubleClick(DoubleClickEvent event) {
			IStructuredSelection selection = (IStructuredSelection) event.getViewer().getSelection();
			Display display = event.getViewer().getControl().getDisplay();
			ElementSelector query = (ElementSelector) selection.getFirstElement();

			view.performSelection(display, query);
			
			viewer.setChecked(selection.getFirstElement(), true);
		}
	}
	
	@Override
	public void dispose() {
		view.dispose();
		super.dispose();
	}
}