package org.drools.compiler.integrationtests;

import org.junit.Test;
import org.kie.api.io.ResourceType;
import org.kie.api.runtime.KieSession;
import org.kie.internal.utils.KieHelper;

import java.util.List;

public class NpeOnQueryTest {

    @Test
    public void test() {
        String drl =
                "import " + FiveState.class.getCanonicalName() + ";\n" +
                "import " + NodeType.class.getCanonicalName() + ";\n" +
                "import " + Knowledge.class.getCanonicalName() + ";\n" +
                "import " + List.class.getCanonicalName() + ";\n" +
                "\n" +
                "rule \"Or Knowledge is unknown\"\n" +
                "    when\n" +
                "        $k: Knowledge( presence == FiveState.UNEVALUATED, nodeType == NodeType.OR )\n" +
                "        allSubKnowledgeAreEvaluated( $k, $childs; )\n" +
                "        not( Knowledge( presence == FiveState.TRUE ) )\n" +
                "    then\n" +
                "        modify( $k ){\n" +
                "            setPresence( FiveState.UNKNOWN )\n" +
                "        }\n" +
                "end\n" +
                "\n" +
                "rule \"Or Knowledge is present\"\n" +
                "    when\n" +
                "        $k: Knowledge( presence == FiveState.UNEVALUATED, nodeType == NodeType.OR )\n" +
                "        allSubKnowledgeAreEvaluated( $k, $childs; )\n" +
                "    then\n" +
                "        modify( $k ){\n" +
                "            setPresence( FiveState.TRUE )\n" +
                "        }\n" +
                "end\n" +
                "\n" +
                "query allSubKnowledgeAreEvaluated( Knowledge parent, List childs )\n" +
                "    childs:= List() from collect ( Knowledge( parent memberOf partOf ))\n" +
                "    forall( Knowledge( presence != FiveState.UNEVALUATED ) from childs )\n" +
                "end\n";

        KieSession ksession = new KieHelper().addContent(drl, ResourceType.DRL)
                                     .build()
                                     .newKieSession();

        Knowledge bk0 = new Knowledge(new Knowledge[0], NodeType.OR, "bk0", FiveState.UNEVALUATED);
        Knowledge bk1 = new Knowledge(new Knowledge[] { bk0 }, NodeType.LEAF, "bk1", FiveState.TRUE);

        ksession.insert( bk0 );
        ksession.insert( bk1 );
        ksession.fireAllRules();
    }

    public enum FiveState {
        TRUE,
        FALSE,
        BOTH,
        UNKNOWN,
        UNEVALUATED
    }

    public enum NodeType {
        LEAF,
        AND,
        OR
    }

    public static class Knowledge {

        private final Knowledge[] partOf;
        private final NodeType nodeType;
        private final String name;
        private FiveState presence;

        public Knowledge(Knowledge[] partOf, NodeType nodeType, String name, FiveState presence) {
            this.partOf = partOf;
            this.nodeType = nodeType;
            this.name = name;
            this.presence = presence;
        }

        public void setPresence(final FiveState presence) {
            this.presence = presence;
        }

        public String getName() {
            return name;
        }

        public FiveState getPresence() {
            return presence;
        }

        public NodeType getNodeType() {
            return nodeType;
        }

        public Knowledge[] getPartOf() {
            return partOf;
        }
    }
}