package org.simantics.district.network.ui.contributions;

import java.util.List;

import javax.inject.Named;

import org.eclipse.e4.core.di.annotations.CanExecute;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.ui.services.IServiceConstants;
import org.eclipse.jface.viewers.ISelection;
import org.simantics.Simantics;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.SelectionHints;
import org.simantics.db.request.Read;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.utils.ui.ISelectionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class CopyDistrictVertexHandler {

    private static final Logger LOGGER = LoggerFactory.getLogger(CopyDistrictVertexHandler.class);
    static List<Resource> elements;
    static boolean cut = true;

    @CanExecute
    public boolean canExecute(@Named(IServiceConstants.ACTIVE_SELECTION) ISelection selection) {
        List<Resource> elements = ISelectionUtils.getPossibleKeys(selection, SelectionHints.KEY_MAIN, Resource.class);
        if (elements.size() != 1)
            return false;
        try {
            return Simantics.getSession().syncRequest(new Read<Boolean>() {

                @Override
                public Boolean perform(ReadGraph graph) throws DatabaseException {
                    DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
                    for (Resource selection : elements) {
                        if (!graph.isInstanceOf(selection, DN.Element)) {
                            return false;
                        }
                    }
                    return true;
                }
            });
        } catch (DatabaseException e) {
            LOGGER.error("Could not evaluate if mapping can be changed for selection {}", elements, e);
            return false;
        }
    }

    @Execute
    public void execute(@Named(IServiceConstants.ACTIVE_SELECTION) Object selection) {
        final List<Resource> elements = ISelectionUtils.getPossibleKeys(selection, SelectionHints.KEY_MAIN, Resource.class);
        // we store these to a static variable for pasting.. maybe not the best solution 
        CopyDistrictVertexHandler.elements = elements;
        //CopyDistrictVertexHandler.cut = cut != null && !cut.isEmpty();
    }
}