package org.simantics.district.network;

import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.simantics.Simantics;
import org.simantics.databoard.Bindings;
import org.simantics.datatypes.literal.RGB;
import org.simantics.datatypes.literal.RGB.Integer;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.procedure.adapter.TransientCacheListener;
import org.simantics.db.common.request.BinaryRead;
import org.simantics.db.common.request.IndexRoot;
import org.simantics.db.common.request.ObjectsWithType;
import org.simantics.db.common.request.ResourceRead;
import org.simantics.db.common.utils.OrderedSetUtils;
import org.simantics.db.exception.BindingException;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.exception.ManyObjectsForFunctionalRelationException;
import org.simantics.db.exception.ServiceException;
import org.simantics.db.indexing.IndexUtils;
import org.simantics.db.layer0.request.PossibleVariable;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.diagram.synchronization.graph.DiagramGraphUtil;
import org.simantics.diagram.synchronization.graph.layer.GraphLayer;
import org.simantics.diagram.synchronization.graph.layer.IGraphLayerUtil;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.layer0.Layer0;
import org.simantics.maps.elevation.server.SingletonTiffTileInterface;
import org.simantics.maps.elevation.server.prefs.MapsElevationServerPreferences;
import org.simantics.modeling.ModelingResources;
import org.simantics.modeling.adapters.NewCompositeActionFactory;
import org.simantics.operation.Layer0X;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.index.quadtree.Quadtree;

public class DistrictNetworkUtil {

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

    public static Resource createEdge(WriteGraph graph, Resource composite, double[] detailedGeometryCoords) throws DatabaseException {
        return createEdge(graph, composite, graph.getPossibleObject(composite, DistrictNetworkResource.getInstance(graph).EdgeDefaultMapping), detailedGeometryCoords);
    }

    public static Resource createEdge(WriteGraph graph, Resource composite, Resource mapping, double[] detailedGeometryCoords) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        if (mapping == null) {
            mapping = graph.getSingleObject(composite, DN.EdgeDefaultMapping);
        }
        
        Resource edge = graph.newResource();
        graph.claim(edge, L0.InstanceOf, DN.Edge);
        
        graph.claim(edge, DN.HasMapping, null, mapping);
        
        OrderedSetUtils.addFirst(graph, composite, edge);
        graph.claim(composite, L0.ConsistsOf, L0.PartOf, edge);
        
        claimFreshElementName(graph, composite, edge);
        
        // We need to put GraphLayer to newLayers so...
        for (Resource layer : graph.getObjects(composite, DiagramResource.getInstance(graph).HasLayer)) {
            IGraphLayerUtil layerUtil = graph.adapt(graph.getSingleObject(layer, Layer0.getInstance(graph).InstanceOf), IGraphLayerUtil.class);
            
            GraphLayer gl = layerUtil.loadLayer(graph, layer);
            gl.forEachTag(tag -> {
                DiagramGraphUtil.tag(graph, edge, tag, true);
            });
        }
        
        // add detailed geometry (if any)
        graph.claimLiteral(edge, DN.Edge_HasGeometry, detailedGeometryCoords, Bindings.DOUBLE_ARRAY);
        return edge;
    }

    /**
     * @param graph
     * @param composite
     * @param coords
     * @param elevation Double.MAX_VALUE to fetch elevation from elevation server (if enabled and has data)
     * @return
     * @throws DatabaseException
     */
    public static Resource createVertex(WriteGraph graph, Resource composite, double[] coords, double elevation) throws DatabaseException {
        Resource defaultVertexMapping = graph.getPossibleObject(composite, DistrictNetworkResource.getInstance(graph).VertexDefaultMapping);
        return createVertex(graph, composite, coords, elevation, defaultVertexMapping);
    }

    /**
     * @param graph
     * @param composite
     * @param coords
     * @param elevation Double.MAX_VALUE to fetch elevation from elevation server (if enabled and has data)
     * @param mapping
     * @return
     * @throws DatabaseException
     */
    public static Resource createVertex(WriteGraph graph, Resource composite, double[] coords, double elevation, Resource mapping) throws DatabaseException {
        // Double.MAX_VALUE is our secret to lookup elevation from elevation server
        if (elevation == Double.MAX_VALUE) {
            // ok, resolve from server or default to 0
            if (MapsElevationServerPreferences.useElevationServer()) {
                // ok! we use new elevation API to resolve possible elevations for the starting points
                try {
                    elevation = SingletonTiffTileInterface.lookup(coords[1], coords[0]).doubleValue();
                } catch (Exception ee) {
                    LOGGER.error("Could not get elevation from tiff interface", ee);
                }
            } else {
                elevation = 0;
            }
        }
        
        Layer0 L0 = Layer0.getInstance(graph);
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        DiagramResource DIA = DiagramResource.getInstance(graph);
        Resource vertex = graph.newResource();
        graph.claim(vertex, L0.InstanceOf, DN.Vertex);
        graph.claimLiteral(vertex, DIA.HasLocation, coords);
        graph.claimLiteral(vertex, DN.Vertex_HasElevation, elevation, Bindings.DOUBLE);
        
        graph.claim(vertex, DN.HasMapping, null, mapping);
        
        OrderedSetUtils.add(graph, composite, vertex);
        graph.claim(composite, L0.ConsistsOf, L0.PartOf, vertex);
        
        claimFreshElementName(graph, composite, vertex);
        
        // We need to put GraphLayer to newLayers so...
        for (Resource layer : graph.getObjects(composite, DiagramResource.getInstance(graph).HasLayer)) {
            IGraphLayerUtil layerUtil = graph.adapt(graph.getSingleObject(layer, Layer0.getInstance(graph).InstanceOf), IGraphLayerUtil.class);
            
            GraphLayer gl = layerUtil.loadLayer(graph, layer);
            gl.forEachTag(tag -> {
                DiagramGraphUtil.tag(graph, vertex, tag, true);
            });
        }
        
        return vertex;
    }
    
    public static Resource joinVertices(WriteGraph graph, Collection<Resource> vertices) throws DatabaseException {
        if (vertices.isEmpty())
            throw new IllegalArgumentException("vertices-collection should not be empty for joining vertices!");
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        Iterator<Resource> verticeIterator = vertices.iterator();
        Resource master = verticeIterator.next();
        while (verticeIterator.hasNext()) {
            Resource slave = verticeIterator.next();
            Resource composite = graph.getSingleObject(slave, Layer0.getInstance(graph).PartOf);
            Collection<Resource> startVertexEdges = graph.getObjects(slave, DN.HasStartVertex_Inverse);
            for (Resource startVertexEdge : startVertexEdges) {
                graph.deny(startVertexEdge, DN.HasStartVertex);
                graph.claim(startVertexEdge, DN.HasStartVertex, master);
            }
            Collection<Resource> endVertexEdges = graph.getObjects(slave, DN.HasEndVertex_Inverse);
            for (Resource endVertexEdge : endVertexEdges) {
                graph.deny(endVertexEdge, DN.HasEndVertex);
                graph.claim(endVertexEdge, DN.HasEndVertex, master);
            }
            OrderedSetUtils.remove(graph, composite, slave);
            // Remove ConsistsOf statement
            graph.deny(composite, Layer0.getInstance(graph).ConsistsOf, slave);
        }
        return master;
    }
    
    public static double calculateDistance(ReadGraph graph, Resource startVertex, Resource endVertex) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        Resource startComposite = graph.getSingleObject(startVertex, L0.PartOf);
        Resource endComposite = graph.getSingleObject(endVertex, L0.PartOf);
        if (!startComposite.equalsResource(endComposite)) {
            throw new DatabaseException("Can not calculate distance between vertices on different composites! " + startVertex + " -> " + endVertex);
        }
        Resource crs = graph.getSingleObject(startComposite, DistrictNetworkResource.getInstance(graph).HasSpatialRefSystem);
        
        CRS crsClass = graph.adapt(crs, CRS.class);
        
        double[] startCoords = graph.getRelatedValue2(startVertex, DiagramResource.getInstance(graph).HasLocation, Bindings.DOUBLE_ARRAY);
        double[] endCoords = graph.getRelatedValue2(endVertex, DiagramResource.getInstance(graph).HasLocation, Bindings.DOUBLE_ARRAY);
        
        return crsClass.calculateDistance(startCoords, endCoords);
    }
    
    public static final String claimFreshElementName(WriteGraph graph, Resource diagram, Resource element) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        DiagramResource DIA = DiagramResource.getInstance(graph);
        // Get name prefix from diagram
        String namePrefix = graph.getPossibleRelatedValue2(diagram, Layer0X.getInstance(graph).HasGeneratedNamePrefix);
        if (namePrefix == null)
            namePrefix = "";
        // Give running name to element and increment the counter attached to the diagram.
        Long l = graph.getPossibleRelatedValue(diagram, DIA.HasModCount, Bindings.LONG);
        if (l == null)
            l = Long.valueOf(0L);
        String name = namePrefix + l.toString();
        graph.claimLiteral(element, L0.HasName, name, Bindings.STRING);
        graph.claimLiteral(diagram, DIA.HasModCount, ++l, Bindings.LONG);
        return name;
    }

    public static Resource getDiagramElement(ReadGraph graph, Resource component) throws DatabaseException {
        if (component == null)
            return null;
        DiagramResource DIA = DiagramResource.getInstance(graph);
        if (graph.isInstanceOf(component, DIA.Element))
            return component;
        ModelingResources MOD = ModelingResources.getInstance(graph);
        Resource element = graph.getPossibleObject(component, MOD.ComponentToElement);
        return element != null && graph.isInstanceOf(element, DIA.Element) ? element : null;
    }

    public static Resource getMappedElement(ReadGraph graph, Resource element) throws DatabaseException {
        if (element == null)
            return null;
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        return graph.getPossibleObject(element, DN.MappedComponent);
    }

    public static Resource getMappedComponent(ReadGraph graph, Resource element) throws DatabaseException {
        if (element == null)
            return null;
        Resource mappedElement = getMappedElement(graph, element);
        if (mappedElement == null)
            return null;
        ModelingResources MOD = ModelingResources.getInstance(graph);
        return graph.getPossibleObject(mappedElement, MOD.ElementToComponent);
    }
    
    public static Resource getMappedComponentCached(ReadGraph graph, Resource vertex) throws DatabaseException {
        return graph.syncRequest(new MappedComponentRequest(vertex), TransientCacheListener.instance());
    }

    public static Resource getMappedDNElement(ReadGraph graph, Resource element) throws DatabaseException {
        if (element == null)
            return null;
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        return graph.getPossibleObject(element, DN.MappedFromElement);
    }

    public static Variable toMappedConfigurationModule(ReadGraph graph, Resource input) throws DatabaseException {
        if (input == null)
            return null;

        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        if (graph.isInstanceOf(input, DN.Element)) {
            Resource mappedElement = getMappedElement(graph, input);
            if (mappedElement == null)
                return null;

            ModelingResources MOD = ModelingResources.getInstance(graph);
            Resource mappedComponent = graph.getPossibleObject(mappedElement, MOD.ElementToComponent);
            if (mappedComponent == null)
                return null;

            return graph.syncRequest(new PossibleVariable(mappedComponent));
        }
        return null;
    }

    public static void toggleDrawMap(WriteGraph graph, Resource diagram) throws ManyObjectsForFunctionalRelationException, BindingException, ServiceException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        Boolean current = graph.getPossibleRelatedValue(diagram, DN.Diagram_drawMapEnabled, Bindings.BOOLEAN);
        if (current == null)
            current = true;
        graph.claimLiteral(diagram, DN.Diagram_drawMapEnabled, !current, Bindings.BOOLEAN);
    }

    public static Boolean drawMapEnabled(ReadGraph graph, Resource diagram) throws ManyObjectsForFunctionalRelationException, BindingException, ServiceException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        Boolean current = graph.getPossibleRelatedValue(diagram, DN.Diagram_drawMapEnabled, Bindings.BOOLEAN);
        return current != null ? current : true;
    }

    public static void changeMapBackgroundColor(WriteGraph graph, Resource diagram, Integer integer) throws DatabaseException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        graph.claimLiteral(diagram, DN.Diagram_backgroundColor, integer, Bindings.getBindingUnchecked(RGB.Integer.class));
    }
    
    public static Boolean trackChangesEnabled(ReadGraph graph, Resource diagram) throws DatabaseException {
        if (diagram != null && graph.hasStatement(diagram)) {
            return Boolean.TRUE.equals(graph.getPossibleRelatedValue(diagram,
                DistrictNetworkResource.getInstance(graph).Diagram_trackChangesEnabled));
        } else {
            return false;
        }
    }

    public static RGB.Integer backgroundColor(ReadGraph graph, Resource diagram) throws DatabaseException {
        return graph.getPossibleRelatedValue(diagram,
                DistrictNetworkResource.getInstance(graph).Diagram_backgroundColor,
                Bindings.getBindingUnchecked(RGB.Integer.class));
    }
    
    public static Resource createNetworkDiagram(WriteGraph graph, Resource target, Resource compositeType, String defaultName, Resource defaultEdgeMapping, Resource defaultVertexMapping, Resource rightClickVertexMapping, Resource leftClickVertexMapping, Resource crs) throws DatabaseException {
        Resource composite = NewCompositeActionFactory.createComposite(graph, target, defaultName, compositeType);

        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        Resource diagram = graph.getSingleObject(composite, ModelingResources.getInstance(graph).CompositeToDiagram);
        graph.claim(diagram, DN.EdgeDefaultMapping, defaultEdgeMapping);
        graph.claim(diagram, DN.VertexDefaultMapping, defaultVertexMapping);
        graph.claim(diagram, DN.RightClickDefaultMapping, rightClickVertexMapping);
        graph.claim(diagram, DN.LeftClickDefaultMapping, leftClickVertexMapping);
        graph.claim(diagram, DN.HasSpatialRefSystem, crs);
        
        // Generated name prefix from composite name
        String compositeName = graph.getRelatedValue2(composite, Layer0.getInstance(graph).HasName, Bindings.STRING);
        graph.claimLiteral(diagram, Layer0X.getInstance(graph).HasGeneratedNamePrefix, "N" + compositeName.substring(compositeName.length() - 1, compositeName.length()));
        
        return composite;
    }

    public static final class MappedComponentRequest extends ResourceRead<Resource> {
        public MappedComponentRequest(Resource element) {
            super(element);
        }

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

    public static class ResourceVertex {
        
        public final boolean isConsumer;
        public final Resource vertex;
        public final double[] coords;
        
        public ResourceVertex(Resource vertex, double[] coords, boolean isConsumer) {
            this.vertex = vertex;
            this.coords = coords;
            this.isConsumer = isConsumer;
        }
    }
    
    public static void changeMappingType(WriteGraph graph, Resource newMapping, List<Resource> elements) throws DatabaseException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        for (Resource element : elements) {
            graph.deny(element, DN.HasMapping);
            graph.claim(element, DN.HasMapping, newMapping);
        }
    }

    public static Stream<Resource> findDNElementsById(ReadGraph graph, Resource context, String idToFind) throws DatabaseException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph); 
        return IndexUtils.findByType(graph,
            graph.syncRequest(new IndexRoot(context)),
            DN.Element
        ).stream().filter(element -> {
            try {
                String id = graph.getPossibleRelatedValue(element, DN.HasId, Bindings.STRING);
                return id != null && id.contains(idToFind);
            } catch (DatabaseException e) {
                LOGGER.error("Could not read id for element {]", element, e);
                return false;
            }
        });
    }
    
    public static Resource findDNElementById(ReadGraph graph, Resource context, String idToFind) throws DatabaseException {
        List<Resource> elements = findDNElementsById(graph, context, idToFind).collect(Collectors.toList());
        if (elements.size() == 1) {
            return elements.iterator().next();
        }
        return null;
    }
    
    public static List<Resource> findDNElementByXYCoordinates(ReadGraph graph, Resource context, double lat, double lon, double padding) throws DatabaseException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        DiagramResource DIA = DiagramResource.getInstance(graph);
        List<Resource> results = new ArrayList<>();
        Collection<Resource> vertices = IndexUtils.findByType(graph, graph.syncRequest(new IndexRoot(context)), DN.Vertex);
        Rectangle2D rect = new Rectangle2D.Double(lat, lon, padding, padding);
        for (Resource vertex : vertices) {
            double[] location = graph.getRelatedValue(vertex, DIA.HasLocation, Bindings.DOUBLE_ARRAY);
            if (rect.contains(location[0], location[1])) {
                results.add(vertex);
            }
        }
        return results;
    }

    public static List<ResourceVertex> nearbyResourceVertices(ReadGraph graph, Resource diagramResource, Resource vertex, Double padding) throws DatabaseException {
        double halfPadding = padding / 2;
        
        Quadtree existingVertices = graph.syncRequest(new ExistingVerticesRead(diagramResource, halfPadding), TransientCacheListener.instance());
        double[] coords = graph.getRelatedValue(vertex, DiagramResource.getInstance(graph).HasLocation, Bindings.DOUBLE_ARRAY);
        double x1 = coords[0] - halfPadding;
        double y1= coords[1] - halfPadding;
        double x2 = coords[0] + halfPadding;
        double y2= coords[1] + halfPadding;
        Envelope e = new Envelope(x1, x2, y1, y2);
        
        List<?> result = existingVertices.query(e);
        @SuppressWarnings("unchecked")
        List<ResourceVertex> vertices = (List<ResourceVertex>) result;
        
        Rectangle2D vertexRectangle = new Rectangle2D.Double(coords[0] - halfPadding, coords[1] - halfPadding, padding, padding);
        
        // let's sort by distance
        List<ResourceVertex> sortedVertices = vertices.stream().filter(rv -> {
            if (rv.vertex.equals(vertex))
                return false;
            
            Rectangle2D nearbyRectangle = new Rectangle2D.Double(rv.coords[0] - halfPadding, rv.coords[1] - halfPadding, padding, padding);
            return vertexRectangle.intersects(nearbyRectangle);
        }).sorted((o1, o2) -> {
            double disto1 = Math.sqrt((Math.pow(coords[0] - o1.coords[0], 2) + (Math.pow(coords[1] - o1.coords[1], 2))));
            double disto2 = Math.sqrt((Math.pow(coords[0] - o2.coords[0], 2) + (Math.pow(coords[1] - o2.coords[1], 2))));
            
            if (o1.vertex.getResourceId() == 2554883) {
                System.err.println("here we are");
            }
            
            return Double.compare(disto1, disto2);
        }).collect(Collectors.toList());
        return sortedVertices;
    }

    public static List<Resource> nearbyVertices(ReadGraph graph, Resource vertex, double padding) throws DatabaseException {
        Resource diagramResource = graph.getSingleObject(vertex, Layer0.getInstance(graph).PartOf);
        return nearbyResourceVertices(graph, diagramResource, vertex, padding)
                .stream()
                .map(rv -> rv.vertex)
                .collect(Collectors.toList());
    }

    public static Quadtree existingVertices(Resource diagramResource, Double padding) throws DatabaseException {
        Quadtree vv = Simantics.getSession().syncRequest(new ExistingVerticesRead(diagramResource, padding));
        return vv;
    }

    public static class ExistingVerticesRead extends BinaryRead<Resource, Double, Quadtree> {

        public ExistingVerticesRead(Resource diagramResource, Double padding) {
            super(diagramResource, padding);
        }

        @Override
        public Quadtree perform(ReadGraph graph) throws DatabaseException {
            Collection<Resource> vertices = graph.syncRequest(new ObjectsWithType(parameter, Layer0.getInstance(graph).ConsistsOf, DistrictNetworkResource.getInstance(graph).Vertex));
            Quadtree vv = new Quadtree();
            for (Resource vertex : vertices) {
                double[] coords = graph.getRelatedValue2(vertex, DiagramResource.getInstance(graph).HasLocation, Bindings.DOUBLE_ARRAY);
                double x1 = coords[0] - parameter2;
                double y1= coords[1] - parameter2;
                double x2 = coords[0] + parameter2;
                double y2= coords[1] + parameter2;
                Envelope e = new Envelope(x1, x2, y1, y2);
                vv.insert(e, new ResourceVertex(vertex, coords, true));
            }
            return vv;
        }
    }

}