package org.simantics.simulation.project;

import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Consumer;

import org.simantics.databoard.Bindings;
import org.simantics.db.Resource;
import org.simantics.db.Session;
import org.simantics.db.VirtualGraph;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.common.request.WriteResultRequest;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.service.VirtualGraphSupport;
import org.simantics.layer0.Layer0;
import org.simantics.scl.runtime.function.Function2;
import org.simantics.simulation.experiment.ExperimentState;
import org.simantics.simulation.experiment.IExperiment;
import org.simantics.simulation.experiment.IExperimentListener;
import org.simantics.simulation.ontology.SimulationResource;
import org.simantics.utils.ui.ErrorLogger;

/**
 * Facade for handling experiment run modeling and experiment activation
 * related tasks.
 * 
 * @author Tuukka Lehtonen
 */
public class ExperimentRuns {

    /**
     * @param session
     * @param experimentResource
     * @param experiment
     * @param listener
     */
    public static void createRun(Session session, Resource experimentResource, IExperiment experiment,
            IExperimentActivationListener listener, Consumer<Resource> successCallback) {
        VirtualGraphSupport support = session.getService(VirtualGraphSupport.class);
        createRun(session, support.getWorkspacePersistent("experiments"), experimentResource, experiment, listener, successCallback);
    }

    /**
     * Create new experiment run in a selected virtual graph.
     * 
     * @param session
     * @param graph
     * @param experimentResource
     * @param experiment
     * @param listener
     */
    public static void createRun(final Session session, VirtualGraph graph, final Resource experimentResource,
            final IExperiment experiment, final IExperimentActivationListener listener,
            final Consumer<Resource> successCallback)
    {
        createRun(session, graph, experimentResource, experiment, SimulationResource.URIs.Run, listener, successCallback);
    }

    public static void createRun(final Session session, VirtualGraph vg, final Resource experimentResource,
            final IExperiment experiment, final String experimentRunTypeURI,
            final IExperimentActivationListener listener, final Consumer<Resource> successCallback)
    {
    	createRun(session, vg, experimentResource, experiment, experimentRunTypeURI, listener, null, successCallback);
    }

    /**
     * Create new experiment run in a selected virtual graph.
     * 
     * @param session
     * @param vg
     * @param experimentResource
     * @param experiment
     * @param experimentRunTypeURI
     * @param listener
     * @param successCallback if non-null invoked with the created run resource
     *        as an argument, just before invoking
     *        listener.onExperimentActivated(experiment)
     */
    public static void createRun(final Session session, VirtualGraph vg, final Resource experimentResource,
            final IExperiment experiment, final String experimentRunTypeURI,
            final IExperimentActivationListener listener,
            final Function2<WriteGraph, Resource, Object> externalWrite,
            final Consumer<Resource> successCallback)
    {
        final AtomicReference<Resource> run = new AtomicReference<>();
        session.asyncRequest(new WriteRequest(vg) {
            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
//                System.out.println("ExperimentActivator " + experimentResource + " " + experiment.getIdentifier());
                run.set( createRun(graph, experimentResource, experiment, experimentRunTypeURI, externalWrite) );
            }
        }, e -> {
            if (e != null) {
                if (listener != null)
                    listener.onFailure(e);
                else
                    ErrorLogger.defaultLogError(e);
            } else {
                attachStateListener(session, experiment, run.get());
                if (successCallback != null)
                    successCallback.accept(run.get());
                if (listener != null)
                    listener.onExperimentActivated(experiment);
            }
        });
    }

    /**
     * Create new experiment run in a selected virtual graph.
     * 
     * @param session
     * @param vg
     * @param experimentResource
     * @param experiment
     * @param experimentRunTypeURI
     * @param listener
     * @param successCallback if non-null invoked with the created run resource
     *        as an argument, just before invoking
     *        listener.onExperimentActivated(experiment)
     */
    public static Resource createRun(WriteGraph graph,
            VirtualGraph vg, 
            Resource experimentResource,
            IExperiment experiment,
            String experimentRunTypeURI,
            Function2<WriteGraph, Resource, Object> externalWrite)
                    throws DatabaseException
    {
        return graph.syncRequest(new WriteResultRequest<Resource>(vg) {
            @Override
            public Resource perform(WriteGraph graph) throws DatabaseException {
                return createRun(graph, experimentResource, experiment, experimentRunTypeURI, externalWrite);
            }
        });
    }

    public static Resource createRun(WriteGraph graph,
            Resource experimentResource,
            IExperiment experiment,
            String experimentRunTypeURI,
            Function2<WriteGraph, Resource, Object> externalWrite)
                    throws DatabaseException
    {
        Layer0 L0 = Layer0.getInstance(graph);
        SimulationResource SIMU = SimulationResource.getInstance(graph);

        Resource run = graph.newResource();
        String label = NameUtils.findFreshLabel(graph, "Experiment", experimentResource);
        graph.claim(run, L0.InstanceOf, null, graph.getResource(experimentRunTypeURI));
        graph.addLiteral(run, L0.HasName, L0.NameOf, L0.String, experiment.getIdentifier(), Bindings.STRING);
        graph.addLiteral(run, L0.HasLabel, L0.HasLabel_Inverse, L0.String, label, Bindings.STRING);
        graph.addLiteral(run, SIMU.HasActivationTime, SIMU.HasActivationTime_Inverse, L0.Long, System.currentTimeMillis(), Bindings.LONG);
        graph.claim(experimentResource, L0.ConsistsOf, L0.PartOf, run);

        markRunActive(graph, run, externalWrite);

        return run;
    }

    /**
     * Mark the run active in the transient virtual graph.
     * 
     * @param graph
     * @param run
     * @param externalWrite 
     * @throws DatabaseException
     */
    private static void markRunActive(
            WriteGraph graph,
            Resource run,
            Function2<WriteGraph, Resource, Object> externalWrite)
                    throws DatabaseException
    {
        SimulationResource SIMU = SimulationResource.getInstance(graph);
        VirtualGraph runtime = graph.getService(VirtualGraph.class);
        graph.syncRequest(new WriteRequest(runtime) {
            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
                graph.claim(run, SIMU.IsActive, run);
                if(externalWrite != null)
                    externalWrite.apply(graph, run);
            }
        });
    }

    /**
     * Add listener for tracking run IsActive state in the graph.
     * 
     * @param session
     * @param experiment
     * @param run
     */
    private static void attachStateListener(final Session session, IExperiment experiment, final Resource run) {
        experiment.addListener(new IExperimentListener() {
            @Override
            public void stateChanged(ExperimentState state) {
                if (state == ExperimentState.DISPOSED) {
                    VirtualGraph runtime = session.getService(VirtualGraph.class);
                    session.asyncRequest(new WriteRequest(runtime) {
                        @Override
                        public void perform(WriteGraph graph) throws DatabaseException {
                            SimulationResource SIMU = SimulationResource.getInstance(graph);
                            graph.denyStatement(run, SIMU.IsActive, run);
                        }
                    }, e -> {
                        if (e != null)
                            ErrorLogger.defaultLogError(e);
                    });
                }
            }
        });
    }

}