package org.simantics.district.route.internal;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.UUID;
import java.util.stream.Collectors;

import org.eclipse.osgi.util.NLS;
import org.simantics.Simantics;
import org.simantics.databoard.Bindings;
import org.simantics.databoard.util.ObjectUtils;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.ObjectsWithType;
import org.simantics.db.common.request.ResourceRead;
import org.simantics.db.common.request.UniqueRead;
import org.simantics.db.common.utils.ListUtils;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.QueryIndexUtils;
import org.simantics.db.layer0.request.PossibleActiveModel;
import org.simantics.db.layer0.util.RemoverUtil;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.district.route.Waypoint;
import org.simantics.district.route.ontology.RouteResource;
import org.simantics.layer0.Layer0;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Tuukka Lehtonen
 */
public class RoutePersistence {

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

    public static Resource getRouteFolder(ReadGraph graph, Resource model) throws DatabaseException {
        List<Resource> diagrams = QueryIndexUtils.searchByType(graph, model, RouteResource.getInstance(graph).RouteFolder);
        if (diagrams.size() > 0)
            return diagrams.get(0);
        return null;
    }

    public static Resource getOrCreateRouteFolder(WriteGraph graph, Resource model) throws DatabaseException {
        Resource rf = getRouteFolder(graph, model);
        if (rf == null) {
            Layer0 L0 = Layer0.getInstance(graph);
            RouteResource RR = RouteResource.getInstance(graph);
            rf = graph.newResource();
            graph.claim(rf, L0.InstanceOf, null, RR.RouteFolder);
            graph.claimLiteral(rf, L0.HasName, L0.NameOf, L0.String, UUID.randomUUID().toString(), Bindings.STRING);
            graph.claim(model, L0.ConsistsOf, L0.PartOf, rf);
        }
        return rf;
    }

    public static Resource createRoute(WriteGraph graph, Resource model, String label, List<Resource> waypoints) throws DatabaseException {
        Resource rf = getOrCreateRouteFolder(graph, model);

        RouteResource RR = RouteResource.getInstance(graph);
        Layer0 L0 = Layer0.getInstance(graph);

        Resource route = ListUtils.create(graph, RR.Route, waypoints);
        graph.claim(rf, L0.ConsistsOf, L0.PartOf, route);
        graph.claimLiteral(route, L0.HasName, UUID.randomUUID().toString(), Bindings.STRING);
        graph.claimLiteral(route, L0.HasLabel, label, Bindings.STRING);

        LOGGER.info("Persisted route {} with label {} and waypoints {}", route, label, waypoints);

        return route;
    }

    public static void updateRoute(WriteGraph graph, Resource route, String label, List<Resource> waypoints) throws DatabaseException {
        RouteResource RR = RouteResource.getInstance(graph);
        Layer0 L0 = Layer0.getInstance(graph);

        String existingLabel = graph.getPossibleRelatedValue(route, L0.HasLabel, Bindings.STRING);
        if (!ObjectUtils.objectEquals(existingLabel, label)) {
            graph.claimLiteral(route, L0.HasLabel, label, Bindings.STRING);
        }

        List<Resource> existingWaypoints = ListUtils.toList(graph, route);
        if (!existingWaypoints.equals(waypoints)) {
            // TODO: optimize this
            ListUtils.removeElements(graph, route, new HashSet<>(existingWaypoints));
            ListUtils.createExisting(graph, RR.Route, waypoints);
        }

        LOGGER.info("Updated route {} with label {} and waypoints {}", route, label, waypoints);
    }

    public static void removeRoute(WriteGraph graph, Resource route) throws DatabaseException {
        RemoverUtil.remove(graph, route);
    }

    public static Waypoint toWaypoint(ReadGraph graph, Resource waypoint) throws DatabaseException {
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        Set<Resource> types = graph.getTypes(waypoint);
        String name = NameUtils.getSafeName(graph, waypoint);
        if (types.contains(DN.Vertex)) {
            String address = graph.getPossibleRelatedValue(waypoint, DN.Vertex_HasAddress, Bindings.STRING);
            String label = address != null
                    ? NLS.bind("Node {0} - {1}", name, address).trim()
                    : NLS.bind("Node {0}", name, address).trim();
            return new WaypointImpl(waypoint, label);
        } else if (types.contains(DN.Edge)) {
            return new WaypointImpl(waypoint, NLS.bind("Edge {0}", name));
        }
        LOGGER.warn("Tried to convert unrecognized resource {} to a route waypoint", waypoint);
        return null;
    }

    public static List<Waypoint> toWaypoints(ReadGraph graph, List<Resource> waypoints) throws DatabaseException {
        List<Waypoint> result = new ArrayList<>();
        for (Resource wpr : waypoints) {
            Waypoint wp = toWaypoint(graph, wpr);
            if (wp != null)
                result.add(wp);
        }
        return result;
    }

    public static List<RouteImpl> findRoutes(ReadGraph graph, Resource model) throws DatabaseException {
        Resource rf = model != null ? getRouteFolder(graph, model) : null;
        if (rf == null)
            return Collections.emptyList();

        Layer0 L0 = Layer0.getInstance(graph);
        RouteResource RR = RouteResource.getInstance(graph);

        List<RouteImpl> routes = new ArrayList<>();

        for (Resource route : graph.syncRequest(new ObjectsWithType(rf, L0.ConsistsOf, RR.Route))) {
            RouteImpl ri = new RouteImpl(graph.getRelatedValue(route, L0.HasLabel, Bindings.STRING))
                    .backend(route)
                    .modelEntity(model)
                    .waypoints(toWaypoints(graph, ListUtils.toList(graph, route)));
            routes.add(ri);
        }

        return routes;
    }

    public static class ModelRoutesRequest extends ResourceRead<List<RouteImpl>> {
        public ModelRoutesRequest(Resource model) {
            super(model);
        }
        @Override
        public List<RouteImpl> perform(ReadGraph graph) throws DatabaseException {
            return findRoutes(graph, resource);
        }
    }

    public static class ActiveModelRoutesRequest extends UniqueRead<List<RouteImpl>> {
        @Override
        public List<RouteImpl> perform(ReadGraph graph) throws DatabaseException {
            return findRoutes(graph, graph.syncRequest(new PossibleActiveModel(Simantics.getProjectResource())));
        }
    }

    public static List<Resource> toResources(List<Waypoint> waypoints) {
        return waypoints.stream()
                .<Resource>map(Waypoint::getObject)
                .collect(Collectors.toList());
    }

}