package org.simantics.selectionview;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.ui.IWorkbenchSite;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.utils.Logger;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.layer0.variable.Variables;
import org.simantics.ui.selection.AnyResource;
import org.simantics.ui.selection.WorkbenchSelectionElement;
import org.simantics.views.swt.SWTViewLoaderProcess;
import org.simantics.views.swt.client.base.SWTRoot;

public class MultiTypedTabContribution extends AbstractTypedTabContribution<Object> {

	public MultiTypedTabContribution(ReadGraph graph, Resource configuration) throws DatabaseException {
	    super(graph, configuration);
	}
	
	static class Contribution extends ModelledTabContributor {

		private String viewURI;
		
		public Contribution(String viewURI) {
			this.viewURI = viewURI;
		}
		
		@Override
		public void createControls(Composite body, IWorkbenchSite site) {

			try {

				final SWTViewLoaderProcess loader = new SWTViewLoaderProcess(null, site);
				final SWTRoot root = loader.load(viewURI, runtime);
				root.createControls(body);
				body.addListener(SWT.Dispose, new Listener() {
					
					@Override
					public void handleEvent(Event event) {
						if(!loader.isDisposed())
							loader.dispose();
					}
					
				});
				
			} catch (DatabaseException e) {

				e.printStackTrace();
				Logger.defaultLogError(e);

			}

		}
		
	    @Override
	    public boolean equals(Object obj) {
	        if (this == obj)
	            return true;
	        else if (obj == null)
	            return false;
	        else if (!(obj instanceof Contribution))
	            return false;
	        Contribution c = (Contribution)obj;
	        return viewURI.equals(c.viewURI);
	    }
	    
	    @Override
	    public int hashCode() {
	    	return viewURI.hashCode();
	    }
		
	}
	
	@Override
	public boolean accept(ReadGraph graph, Object input) throws DatabaseException {
	    return true;
	}
	
	@Override
	public boolean accept(ReadGraph graph, Object input, Collection<Resource> type) throws DatabaseException {
	    return true;
	}
	
	@Override
	public void getContributors(ReadGraph graph, Object input, Integer priority, String label, Collection<ComparableTabContributor> result) throws DatabaseException {
        Collection<?> objects;
        if (input instanceof Collection<?>) {
            objects = (Collection<?>) input;
        } else {
            objects = Collections.singletonList(input);
        }
        
        SelectionViewResources SEL = SelectionViewResources.getInstance(graph);
        Resource view = graph.getPossibleObject(configuration, SEL.VariableTabContribution_HasView);
        if(view == null) {
            throw new DatabaseException("No view for " + graph.getPossibleURI(configuration));
        }

        Set<Variable> actualResult = new HashSet<>(objects.size());
        for (Object obj : objects) {
            Resource resource = getPossibleResource(graph, obj);
            if (resource == null)
                continue;
            
            Collection<Resource> ts = graph.getTypes(resource);
            
            if (!Collections.disjoint(types, ts)) {
                Variable variable = Variables.getVariable(graph, resource);
                actualResult.add(variable);
            }
        }
        if (!actualResult.isEmpty()) {
            final String viewURI = graph.getPossibleURI(view);
            result.add(new ComparableTabContributor(new Contribution(viewURI), priority, actualResult, label));
        }
	}

    private Resource getPossibleResource(ReadGraph graph, Object obj) {
        if (obj instanceof Resource)
            return (Resource) obj;
        if (obj instanceof WorkbenchSelectionElement)
            return ((WorkbenchSelectionElement) obj).getContent(new AnyResource(graph));
        return null;
    }
}