package org.simantics.district.selection.ui;

import java.util.Collection;

import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.TreeSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.TreeViewerColumn;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Tree;
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 TreeViewer viewer;

	private ElementSelectionView view;

	public ElementSelectorTableUI(Composite parent, int style, ElementSelectionView view) {
		super(parent, style);
		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();
		setContentProvider();
		createSelectorListener(parent);
		enableToolTips();
		configureTable();
	}

	public Tree getTree() {
		return viewer.getTree();
	}

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

	private TreeViewer createViewer() {
		return new TreeViewer(this, SWT.FULL_SELECTION);
	}

	private void configureTable() {
		Tree table = viewer.getTree();
		table.setHeaderVisible(true);
		table.setLinesVisible(true);

		createNameColumn();
		createQueryColumn();
	}

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

	private void setContentProvider() {
		viewer.setContentProvider(new ITreeContentProvider() {
			@Override
			public boolean hasChildren(Object element) {
				return false;
			}
	
			@Override
			public Object getParent(Object element) {
				return null;
			}
	
			@Override
			public Object[] getElements(Object inputElement) {
				if (inputElement == null || !(inputElement instanceof Collection))
					return new Object[0];
				
				return ((Collection<?>)inputElement).toArray();
			}
	
			@Override
			public Object[] getChildren(Object parentElement) {
				return null;
			}
	
			@Override
			public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
				ITreeContentProvider.super.inputChanged(viewer, oldInput, newInput);
			}
		});
	}

	private TreeViewerColumn createNameColumn() {
		TreeViewerColumn column = new TreeViewerColumn(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) {
				return null;
			}
		});
		return column;
	}

	private TreeViewerColumn createQueryColumn() {
		TreeViewerColumn column = new TreeViewerColumn(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();
			}
			
			@Override
			public Image getImage(Object element) {
				return null;
			}
		});
		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) {
			TreeSelection selection = (TreeSelection) event.getViewer().getSelection();
			Display display = event.getViewer().getControl().getDisplay();
			ElementSelector query = (ElementSelector) selection.getFirstElement();
			
			view.performSelection(display, query);
		}
	}
}