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

import java.awt.geom.Point2D;
import java.util.Collections;
import java.util.List;

import org.simantics.Simantics;
import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.procedure.adapter.TransientCacheListener;
import org.simantics.db.common.request.ResourceRead;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.exception.MissingVariableException;
import org.simantics.db.layer0.exception.MissingVariableValueException;
import org.simantics.db.layer0.exception.PendingVariableException;
import org.simantics.db.layer0.util.Layer0Utils;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.layer0.variable.Variables;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.district.network.DistrictNetworkUtil;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.district.network.ui.nodes.DistrictNetworkEdgeNode;
import org.simantics.district.network.ui.nodes.DistrictNetworkNodeUtils;
import org.simantics.district.network.ui.nodes.DistrictNetworkVertexNode;
import org.simantics.layer0.Layer0;
import org.simantics.scenegraph.INode;
import org.simantics.scl.compiler.top.ValueNotFound;
import org.simantics.scl.osgi.SCLOsgi;
import org.simantics.scl.runtime.SCLContext;
import org.simantics.scl.runtime.function.Function1;
import org.simantics.scl.runtime.tuple.Tuple3;
import org.simantics.structural.stubs.StructuralResource2;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DistrictNetworkHoverInfoStyle {

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

    private static final String ACTIONS_MODULE = "Actions";
    private static final String HOVER_CONTRIBUTION = "hoverContribution";

    public static class StyleResult {
        Point2D origin;
        List<Tuple3> labels;

        public StyleResult(Point2D origin, List<Tuple3> labels) {
            this.origin = origin;
            this.labels = labels;
        }

        public Point2D getOrigin() {
            return origin;
        }

        public List<Tuple3> getLabels() {
            return labels;
        }
    }

    public static StyleResult doCalculateStyleResult(ReadGraph graph, Resource runtimeDiagram, Resource mapElement) throws DatabaseException {
        DiagramResource DIA = DiagramResource.getInstance(graph);
        StructuralResource2 STR = StructuralResource2.getInstance(graph);

        String variableURI = graph.getPossibleRelatedValue(runtimeDiagram, DIA.RuntimeDiagram_HasVariable,
                Bindings.STRING);
        Variable activeVariable = org.simantics.db.layer0.variable.Variables.getPossibleVariable(graph, variableURI);
        if (activeVariable == null)
            return null;

        Resource module = DistrictNetworkUtil.getMappedComponentCached(graph, mapElement);
        if (module == null)
            return null;

        Resource moduleType = graph.getPossibleType(module, STR.Component);
        if (moduleType == null)
            return null;

        Function1<Variable, List<Tuple3>> function = getUCTextGridFunctionCached(graph, moduleType);
        if (function == null)
            return null;

        List<Tuple3> result;
        try {
            Variable variable = Variables.getVariable(graph, module);
            Variable moduleVariable = Variables.possibleActiveVariable(graph, variable);
            if (moduleVariable == null)
                moduleVariable = variable;

            result = Simantics.applySCLRead(graph, function, moduleVariable);
        } catch (PendingVariableException | MissingVariableValueException e) {
            result = Collections.singletonList(new Tuple3("<pending>", "", ""));
        } catch (MissingVariableException e) {
            // the requested variable is missing from the UC
            String message = e.getMessage();
            LOGGER.warn("Missing variable for calculating style with function {} {}", function, message);
            result = Collections.singletonList(new Tuple3("<" + message + ">", "", ""));
        }

        Point2D point = calculatePoint(graph, mapElement);

        return new StyleResult(point, result);
    }

    public static Point2D calculatePoint(ReadGraph graph, Resource mapElement) throws DatabaseException {
        Point2D point;
        DiagramResource DIA = DiagramResource.getInstance(graph);
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        if (graph.isInstanceOf(mapElement, DN.Vertex)) {
            double[] coords = graph.getRelatedValue(mapElement, DIA.HasLocation);
            point = DistrictNetworkNodeUtils.calculatePoint2D(new Point2D.Double(coords[0], coords[1]), null);
        } else if (graph.isInstanceOf(mapElement, DN.Edge)) {
            Resource v1 = graph.getSingleObject(mapElement, DN.HasStartVertex);
            double[] coords1 = graph.getRelatedValue(v1, DIA.HasLocation);
            Resource v2 = graph.getSingleObject(mapElement, DN.HasEndVertex);
            double[] coords2 = graph.getRelatedValue(v2, DIA.HasLocation);
            point = DistrictNetworkNodeUtils.calculatePoint2D(
                    new Point2D.Double((coords1[0] + coords2[0]) / 2, (coords1[1] + coords2[1]) / 2), null);
        } else {
            return null;
        }
        return point;
    }

    public static Point2D calculatePoint(INode node, int zoomLevel, Point2D result) {
        if (node instanceof DistrictNetworkVertexNode) {
            DistrictNetworkVertexNode vertex = (DistrictNetworkVertexNode) node;
            return DistrictNetworkNodeUtils.calculatePoint2D(vertex.getVertex().getPoint(), result);
        } else if (node instanceof DistrictNetworkEdgeNode) {
            DistrictNetworkEdgeNode edge = (DistrictNetworkEdgeNode) node;
            Point2D cp = edge.getCenterPoint(zoomLevel);
            if (result == null)
                result = new Point2D.Double();
            result.setLocation(cp);
            return result;
        }
        return null;
    }

    private static Function1<Variable, List<Tuple3>> getUCTextGridFunctionCached(ReadGraph graph, Resource componentType)
             throws DatabaseException {
        return graph.syncRequest(new UCTextGridFunctionRequest(componentType), TransientCacheListener.instance());
    }

    private static final class UCTextGridFunctionRequest extends ResourceRead<Function1<Variable, List<Tuple3>>> {
        public UCTextGridFunctionRequest(Resource resource) {
            super(resource);
        }

        @SuppressWarnings("unchecked")
        @Override
        public Function1<Variable, List<Tuple3>> perform(ReadGraph graph) throws DatabaseException {
            Resource actionsModule = Layer0Utils.getPossibleChild(graph, resource, ACTIONS_MODULE);
            if (actionsModule == null || !graph.isInstanceOf(actionsModule, Layer0.getInstance(graph).SCLModule))
                return null;

            String uri = graph.getURI(actionsModule);
            SCLContext sclContext = SCLContext.getCurrent();
            Object oldGraph = sclContext.get("graph");
            try {
                sclContext.put("graph", graph);
                return (Function1<Variable, List<Tuple3>>) SCLOsgi.MODULE_REPOSITORY.getValue(uri, HOVER_CONTRIBUTION);
            } catch (ValueNotFound e1) {
                return null;
            } finally {
                sclContext.put("graph", oldGraph);
            }
        }
    }

}