package org.simantics.district.network;

import java.util.Collection;
import java.util.Iterator;

import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.utils.OrderedSetUtils;
import org.simantics.db.exception.DatabaseException;
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.operation.Layer0X;

public class DistrictNetworkUtil {

    public static Resource createEdge(WriteGraph graph, Resource composite) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        
        Resource edge = graph.newResource();
        graph.claim(edge, L0.InstanceOf, DN.Edge);
        
        Resource defaultEdgeMapping = graph.getPossibleObject(composite, DN.EdgeDefaultMapping);
        graph.claim(edge, DN.HasMapping, defaultEdgeMapping);
        
        OrderedSetUtils.add(graph, composite, edge);
        graph.claim(composite, L0.ConsistsOf, L0.PartOf, edge);
        
        claimFreshElementName(graph, composite, edge);
        return edge;
    }
    
    public static Resource createVertex(WriteGraph graph, Resource composite, double[] coords) throws DatabaseException {
        Resource defaultVertexMapping = graph.getPossibleObject(composite, DistrictNetworkResource.getInstance(graph).VertexDefaultMapping);
        return createVertex(graph, composite, coords, defaultVertexMapping);
    }
    
    public static Resource createVertex(WriteGraph graph, Resource composite, double[] coords, Resource mapping) throws DatabaseException {
        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.claim(vertex, DN.HasMapping, 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;
    }
}