package org.simantics.district.network.ui;

import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.function.Consumer;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IEditorPart;
import org.simantics.Simantics;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.request.UnaryRead;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.request.PossibleModel;
import org.simantics.db.layer0.variable.RVI;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.layer0.variable.Variables;
import org.simantics.district.network.DistrictNetworkUtil;
import org.simantics.g2d.canvas.ICanvasContext;
import org.simantics.g2d.diagram.DiagramHints;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;
import org.simantics.modeling.actions.NavigateToTarget;
import org.simantics.scl.runtime.tuple.Tuple4;
import org.simantics.ui.selection.WorkbenchSelectionUtils;
import org.simantics.utils.threads.ThreadUtils;
import org.simantics.utils.ui.ISelectionUtils;
import org.simantics.utils.ui.SWTUtils;

/**
 * @author Tuukka Lehtonen
 * @since 1.35.0
 */
public class DistrictNetworkUIUtil {

    public static Resource getInputResource(ReadGraph graph, Object input) throws DatabaseException {
        if (input instanceof Resource) {
            return (Resource) input;
        } else if (input instanceof Variable) {
            return ((Variable) input).getPossibleRepresents(graph);
        } else if (input instanceof ISelection) {
            return ISelectionUtils.filterSingleSelection((ISelection) input, Resource.class);
        } else {
            return WorkbenchSelectionUtils.getPossibleResource(graph, input);
        }
    }

    public static class GetInputResource extends UnaryRead<Object, Resource> {

        public GetInputResource(Object input) {
            super(input);
        }

        @Override
        public Resource perform(ReadGraph graph) throws DatabaseException {
            return getInputResource(graph, parameter);
        }

    }

    public static class Input extends Tuple4 {
        public Input(Resource model, Resource diagram, Resource element, RVI diagramCompositeRvi) {
            super(model, diagram, element, diagramCompositeRvi);
        }
        public Resource model() {
            return (Resource) get(0);
        }
        public Resource diagram() {
            return (Resource) get(1);
        }
        public Resource element() {
            return (Resource) get(2);
        }
        public RVI rvi() {
            return (RVI) get(3);
        }
    }

    public static class FindMappedDNElement extends UnaryRead<Object, Input> {

        public FindMappedDNElement(Object parameter) {
            super(parameter);
        }

        @Override
        public Input perform(ReadGraph graph) throws DatabaseException {
            Resource e = DistrictNetworkUtil.getMappedDNElement(graph,
                    DistrictNetworkUtil.getDiagramElement(graph,
                            getInputResource(graph, parameter)));
            return e != null ? graph.syncRequest(new ElementToInput(e)) : null;
        }

    }

    public static class FindMappedComponent extends UnaryRead<Object, Input> {

        public FindMappedComponent(Object parameter) {
            super(parameter);
        }

        @Override
        public Input perform(ReadGraph graph) throws DatabaseException {
            Resource e = DistrictNetworkUtil.getMappedElement(graph,
                    getInputResource(graph, parameter));
            return e != null ? graph.syncRequest(new ElementToInput(e)) : null;
        }

    }

    public static class ElementToInput extends UnaryRead<Resource, Input> {

        public ElementToInput(Resource element) {
            super(element);
        }

        @Override
        public Input perform(ReadGraph graph) throws DatabaseException {
            Layer0 L0 = Layer0.getInstance(graph);
            Resource diagram = graph.getPossibleObject(parameter, L0.PartOf);
            if (diagram == null)
                return null;

            Resource model = graph.syncRequest(new PossibleModel(diagram));
            if (model == null)
                return null;

            RVI rvi = getDiagramCompositeRvi(graph, diagram);
            if (rvi == null)
                return null;

            return new Input(model, diagram, parameter, rvi);
        }

        private static RVI getDiagramCompositeRvi(ReadGraph graph, Resource diagram) throws DatabaseException {
            ModelingResources MOD = ModelingResources.getInstance(graph);
            Resource composite = graph.getPossibleObject(diagram, MOD.DiagramToComposite);
            if (composite == null)
                return null;
            Variable v = Variables.getPossibleVariable(graph, composite);
            return v != null ? v.getPossibleRVI(graph) : null;
        }

    }

    public static Consumer<IEditorPart> editorActivationCallback(final Collection<? extends Object> selectedObjects) {
        return part -> {
            final ICanvasContext openedCanvas = (ICanvasContext) part.getAdapter(ICanvasContext.class);
            assert openedCanvas != null;
            // CanvasContext-wide denial of initial zoom-to-fit on diagram open.
            openedCanvas.getDefaultHintContext().setHint(DiagramHints.KEY_INITIAL_ZOOM_TO_FIT, Boolean.FALSE);
            ThreadUtils.asyncExec(openedCanvas.getThreadAccess(),
                    NavigateToTarget.elementSelectorZoomer(openedCanvas, selectedObjects, false));
        };
    }

    public static void openEditorWithSelection(String editorId, Input input, Object... selection) {
        NavigateToTarget.editorActivator(
                editorId,
                input.diagram(),
                input.model(),
                input.rvi(),
                DistrictNetworkUIUtil.editorActivationCallback(Arrays.asList(selection)))
        .run();
    }

    public static void openDNDiagramEditorWithSelection(Input input, Object... selection) {
        openEditorWithSelection(DistrictDiagramEditor.ID, input, selection);
    }

    public static boolean openDNDiagramWithSelection(Display display, List<Resource> dnElements) throws DatabaseException {
        if (dnElements.isEmpty())
            return false;

        Input in = Simantics.getSession().syncRequest(
                new ElementToInput(dnElements.get(0)));
        if (in == null)
            return false;

        SWTUtils.asyncExec(display,
                () -> openDNDiagramEditorWithSelection(in, dnElements.toArray()));
        return true;
    }

}