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.profile.StyleBase;
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.DistrictNetworkHoverInfoNode;
import org.simantics.district.network.ui.nodes.DistrictNetworkNodeUtils;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;
import org.simantics.scenegraph.INode;
import org.simantics.scenegraph.profile.EvaluationContext;
import org.simantics.scenegraph.profile.common.ProfileVariables;
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 extends StyleBase<DistrictNetworkHoverInfoStyle.StyleResult> {

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

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

	public 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 DistrictNetworkHoverInfoStyle(Resource style) throws DatabaseException {
		super(style);
	}
	
	String currentRowKey;
	
	protected Resource getConfigurationComponent(ReadGraph graph, Resource element) throws DatabaseException {
		ModelingResources MOD = ModelingResources.getInstance(graph);
		DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
		
		Resource mappedElement = graph.getPossibleObject(element, DN.MappedComponent);
		return mappedElement != null ? graph.getPossibleObject(mappedElement, MOD.ElementToComponent) : null;
	}
	
	@Override
	public StyleResult calculateStyle(ReadGraph graph, Resource runtimeDiagram, Resource entry,
			Resource mapElement, Variable configuration) 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;
		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 new StyleResult(point, result);
	}
	
	@Override
	public void applyStyleForNode(EvaluationContext observer, INode parent, StyleResult results) {
		if (results == null) {
			cleanupStyleForNode(observer, parent);
			return;
		}
		
		DistrictNetworkHoverInfoNode node = ProfileVariables.claimChild(parent, "*", DistrictNetworkHoverInfoNode.NODE_KEY, DistrictNetworkHoverInfoNode.class, observer);
		if (node == null)
			return;
		
		node.setLabels(results.getLabels());
		node.setOrigin(results.getOrigin());
	}
	
	@Override
	protected void cleanupStyleForNode(EvaluationContext observer, INode node) {
		ProfileVariables.denyChild(node, "*", DistrictNetworkHoverInfoNode.NODE_KEY);
	}
	
	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);
			}
		}
	}
}