/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.drools.compiler.oopath;

import java.util.Collection;
import org.assertj.core.api.Assertions;
import org.drools.compiler.oopath.model.Child;
import org.drools.compiler.oopath.model.Man;
import org.junit.Test;
import org.kie.api.io.ResourceType;
import org.kie.api.runtime.KieSession;
import org.kie.internal.utils.KieHelper;

public class OOPathAccumulateTest {

    @Test
    public void testAccumulateAverage() {
        testAccumulate("average", 10);
    }

    @Test
    public void testAccumulateMin() {
        testAccumulate("min", 8);
    }

    @Test
    public void testAccumulateMax() {
        testAccumulate("max", 12);
    }

    @Test
    public void testAccumulateCount() {
        testAccumulate("count", 2);
    }

    @Test
    public void testAccumulateSum() {
        testAccumulate("sum", 20);
    }

    @Test
    public void testAccumulateCollectList() {
        testAccumulateCollection("collectList", 12, 8);
    }

    @Test
    public void testAccumulateCollectSet() {
        testAccumulateCollection("collectSet", 12, 8);
    }

    private void testAccumulate(final String accumulateFunction, final Number expectedResult) {
        // DROOLS-1265
        final String drl =
                "import org.drools.compiler.oopath.model.*;\n" +
                        "global java.lang.Object globalVar\n" +
                        "\n" +
                        "rule R when\n" +
                        "  accumulate ( Adult( $child: /children ) ; $accumulateResult: " + accumulateFunction + "($child.getAge()) )\n" +
                        "then\n" +
                        "  kcontext.getKieRuntime().setGlobal(\"globalVar\", $accumulateResult);\n" +
                        "end\n";

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

        final Man bob = new Man( "Bob", 40 );
        bob.addChild( new Child( "Charles", 12 ) );
        bob.addChild( new Child( "Debbie", 8 ) );

        ksession.insert( bob );
        ksession.fireAllRules();

        final Number result = (Number) ksession.getGlobal("globalVar");
        if (result instanceof Double) {
            Assertions.assertThat(expectedResult.doubleValue()).isEqualTo(result.doubleValue());
        } else {
            Assertions.assertThat(expectedResult.longValue()).isEqualTo(result.longValue());
        }
    }

    private void testAccumulateCollection(final String accumulateFunction, final Integer... expectedResults) {
        final String drl =
                "import org.drools.compiler.oopath.model.*;\n" +
                        "global java.util.Collection<Integer> globalVar\n" +
                        "\n" +
                        "rule R when\n" +
                        "  accumulate ( Adult( $child: /children ) ; $accumulateResult: " + accumulateFunction + "($child.getAge()) )\n" +
                        "then\n" +
                        "  kcontext.getKieRuntime().setGlobal(\"globalVar\", $accumulateResult);\n" +
                        "end\n";

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

        final Man bob = new Man( "Bob", 40 );
        bob.addChild( new Child( "Charles", 12 ) );
        bob.addChild( new Child( "Debbie", 8 ) );

        ksession.insert( bob );
        ksession.fireAllRules();

        final Collection<Integer> result = (Collection<Integer>) ksession.getGlobal("globalVar");
        Assertions.assertThat(result).containsExactlyInAnyOrder(expectedResults);
    }
}