package org.simantics.document.server.request;

import gnu.trove.set.hash.THashSet;

import java.util.Collection;
import java.util.Collections;
import java.util.Set;

import org.simantics.databoard.Bindings;
import org.simantics.db.AsyncReadGraph;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.request.AsyncReadRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.request.VariableChildren;
import org.simantics.db.layer0.request.VariableRead;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.procedure.AsyncProcedure;
import org.simantics.document.base.ontology.DocumentationResource;
import org.simantics.utils.threads.logger.ITask;
import org.simantics.utils.threads.logger.ThreadLogger;

public class NodesRequest2 extends VariableRead<Set<Variable>> {

    public NodesRequest2(Variable var) {
        super(var);
    }

    @Override
    public Set<Variable> perform(ReadGraph graph) throws DatabaseException {

        ITask task = DocumentRequest.PROFILE ? ThreadLogger.task(this) : null;

        DocumentationResource DOC = DocumentationResource.getInstance(graph);

        Resource type = variable.getPossibleType(graph);
        if(type == null) {
            if(DocumentRequest.PROFILE) task.finish();
            return Collections.emptySet();
        }

        if(!graph.isInheritedFrom(type, DOC.Components_Component)) {
            if(DocumentRequest.PROFILE) task.finish();
            return Collections.emptySet();
        }

        Boolean pathExists = variable.getPossiblePropertyValue(graph, DOC.Properties_pathExists, Bindings.BOOLEAN);
        if(pathExists != null && !pathExists) {
            if(DocumentRequest.PROFILE) task.finish();
            return Collections.emptySet();
        }

        if(graph.isInheritedFrom(type, DOC.Components_PrimitiveComponent)) {
            if(DocumentRequest.PROFILE) task.finish();
            return Collections.singleton(variable);
        } else {
            Set<Variable> result = new THashSet<Variable>();
            Collection<Variable> children = graph.syncRequest(new VariableChildren(variable));
            graph.syncRequest(new AsyncReadRequest() {

                @Override
                public void run(AsyncReadGraph graph) throws DatabaseException {

                    for(Variable child : children) {
                        graph.asyncRequest(new NodesRequest2(child), new AsyncProcedure<Set<Variable>>() {

                            @Override
                            public void execute(AsyncReadGraph graph, Set<Variable> vars) {
                                synchronized(result) {
                                    result.addAll(vars);
                                }
                            }

                            @Override
                            public void exception(AsyncReadGraph graph, Throwable throwable) {
                            }
                            
                        });
                    }

                }

            });
            
            if(DocumentRequest.PROFILE) task.finish();
            return result;
            
        }

    }

}