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

import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.ui.PlatformUI;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.Session;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.procedure.adapter.TransientCacheListener;
import org.simantics.db.common.request.ResourceRead;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.district.network.techtype.requests.TechTypeTableData;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.adapters.ExistingInstancesRemover;
import org.simantics.modeling.adapters.RemoveInstancesDialog;
import org.simantics.modeling.adapters.RemoveInstancesDialog.Content;
import org.simantics.utils.strings.AlphanumComparator;

public class TechTypeTableRemover extends ExistingInstancesRemover {

	public TechTypeTableRemover(Resource resource) {
		super(resource, "Tech Type Table");
	}
	
	@Override
	public void remove(WriteGraph graph) throws DatabaseException {
		DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
		
		Resource componentType = graph.getPossibleObject(resource, DN.TechType_TechTypeTable_HasComponentType);
		if (componentType == null) {
			justRemove(graph);
			return;
		}
		
		super.remove(graph, resource, componentType, componentType);
	}

	@Override
	protected Set<Resource> discoverInstances(WriteGraph graph, Resource componentType) throws DatabaseException {
		Resource keyPredicate = graph.syncRequest(new PossibleTechTypeKeyPredicate(componentType), TransientCacheListener.instance());
		if (keyPredicate == null)
			return Collections.emptySet();
		Map<String, Map<String, String>> data = graph.syncRequest(new TechTypeTableData(resource), TransientCacheListener.instance());
		
		Set<Resource> used = new HashSet<>();
		for (Resource comp : super.discoverInstances(graph, componentType)) {
			Object code = graph.getPossibleRelatedValue(comp, keyPredicate);
			if (code != null && code instanceof String && data.containsKey(code)) {
				used.add(comp);
			}
		}
		
		return used;
	}
	
	@Override
	protected void confirmRemoval(WriteGraph graph, final Set<Resource> instances, final String typeDescription, final String typeName) throws DatabaseException {
		Map<Resource, String> instanceAddresses = resolveInstanceAddresses(graph, instances);
		final RemoveInstancesDialog.Content[] content = new RemoveInstancesDialog.Content[instanceAddresses.size()];
		int i = 0;
		for (Map.Entry<Resource, String> entry : instanceAddresses.entrySet()) {
			content[i] = new RemoveInstancesDialog.Content(entry.getValue());
			++i;
		}
		Arrays.sort(content, new Comparator<RemoveInstancesDialog.Content>() {
			@Override
			public int compare(Content o1, Content o2) {
				return AlphanumComparator.CASE_INSENSITIVE_COMPARATOR.compare(o1.label, o2.label);
			}
		});

		final Session session = graph.getSession();

		if (PlatformUI.isWorkbenchRunning()) {
			PlatformUI.getWorkbench().getDisplay().asyncExec(new Runnable() {
				@Override
				public void run() {
					RemoveInstancesDialog dialog = new RemoveInstancesDialog(
							PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(),
							"Remove " + typeDescription + "?",
							typeDescription + " for '" + typeName + "' is still in use in " + instances.size() + " instances. Are you sure you want to remove it?",
							content);
					int result = dialog.open();
					boolean doIt = result == IDialogConstants.OK_ID;
					if (!doIt)
						return;
					session.asyncRequest(new WriteRequest() {
						@Override
						public void perform(WriteGraph graph) throws DatabaseException {
							justRemove(graph);
						}
					});
				}
			});
		} else {
			// Just do it without confirmation when no user agent is available.
			justRemove(graph);
		}
	}
}

class PossibleTechTypeKeyPredicate extends ResourceRead<Resource> {
	public PossibleTechTypeKeyPredicate(Resource componentType) {
		super(componentType);
	}

	@Override
	public Resource perform(ReadGraph graph) throws DatabaseException {
		Layer0 L0 = Layer0.getInstance(graph);
		DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
		
		for (Resource r : graph.getObjects(resource, L0.DomainOf)) {
			Resource accessor = graph.getPossibleObject(r, L0.valueAccessor);
			if (accessor.equals(DN.TechType_Functions_techTypeCodeValueAccessor)) {
				return r;
			}
		}
		
		return null;
	}
}