package org.simantics.district.selection.ui.handlers;

import java.util.Collection;

import javax.inject.Inject;

import org.eclipse.e4.core.contexts.IEclipseContext;
import org.eclipse.e4.core.di.annotations.CanExecute;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.ui.model.application.ui.basic.MPart;
import org.eclipse.e4.ui.services.IServiceConstants;
import org.eclipse.e4.ui.workbench.IWorkbench;
import org.eclipse.e4.ui.workbench.modeling.EPartService;
import org.eclipse.e4.ui.workbench.modeling.ESelectionService;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.widgets.Shell;
import org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.district.selection.ElementSelector;
import org.simantics.district.selection.ElementSelector.ExplicitGenerator;
import org.simantics.district.selection.ui.parts.EditSelectorDialog;
import org.simantics.district.selection.ui.parts.ElementSelectionView;
import org.simantics.utils.ui.AdaptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class EditElementSelector {

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

	@Inject
	EPartService partService;
	
	@CanExecute
	public boolean canExecute(ESelectionService selectionService) {
		MPart part = partService.getActivePart();
		if (part == null) return false;
		
		Object object = part.getObject();
		if (object == null || !(object instanceof ElementSelectionView))
			return false;
		
		ElementSelectionView view = (ElementSelectionView)object;
		return view.getSelectedItem() != null;
	}

	@Execute
	public void editElementSelector(IEclipseContext context, IWorkbench workbench) {
		Object currentSelection = context.get(IServiceConstants.ACTIVE_SELECTION);
		
		MPart part = partService.getActivePart();
		if (part == null) return;
		
		Object object = part.getObject();
		if (object == null || !(object instanceof ElementSelectionView))
			return;
		
		ElementSelectionView view = (ElementSelectionView)object;
		
		Collection<Resource> selection;
		ElementSelector selectedItem = view.getSelectedItem();
		if (selectedItem.getGenerator() instanceof ExplicitGenerator) {
			selection = ((ExplicitGenerator)selectedItem.getGenerator()).elements;
		}
		else {
			selection = AdaptionUtils.adaptToCollection(currentSelection, Resource.class);
		}
		
		Shell shell = context.getActive(Shell.class);
		EditSelectorDialog dialog = new EditSelectorDialog(shell, selectedItem, selection);
		
		LOGGER.debug("Opening dialog");
		int result = dialog.open();
		LOGGER.debug("Dialog closed with result code " + result);
		if (result == Window.OK) {
			try {
				dialog.writeSelection();
			} catch (DatabaseException e) {
				LOGGER.error("Writing new element selection failed", e);
			}
		}
	}
}