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 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 *
 *   https://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
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package org.apache.jena.sparql.engine.iterator;

import static org.junit.jupiter.api.Assertions.assertEquals;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;

import org.junit.jupiter.api.Test;

import org.apache.jena.atlas.iterator.Iter;
import org.apache.jena.graph.NodeFactory;
import org.apache.jena.sparql.core.Var;
import org.apache.jena.sparql.engine.QueryIterator;
import org.apache.jena.sparql.engine.binding.Binding;
import org.apache.jena.sparql.engine.binding.BindingFactory;

public abstract class AbstractTestDistinctReduced {

    static List<String> data1 =     Arrays.asList("0","1","1","3","9","5","6","8","9","0");
    static List<String> results1 =  Arrays.asList("0","1",    "3","9","5","6","8"        );
    static List<String> data2 =     Arrays.asList("0","0","0","0");
    static List<String> results2 =  Arrays.asList("0","0","0","0");

    static Var var_a = Var.alloc("a");
    static Var var_b = Var.alloc("b");

    private static List<Binding> build(List<String> items) {
        return items.stream().sequential()
                .map((s)-> BindingFactory.binding(var_a, NodeFactory.createLiteralString(s)))
                .toList();
    }

    protected abstract QueryIterator createQueryIter(List<Binding> data);

    @Test public void distinct0() {
        distinct(new ArrayList<>(), new ArrayList<>());
    }

    @Test public void distinct1() {
        List<String> data =     Arrays.asList("0","1","1","3","9","5","6","8","9","0");
        List<String> results =  Arrays.asList("0","1",    "3","9","5","6","8"        );
        distinct(data, results);
    }

    @Test public void distinct2() {
        List<String> data =     Arrays.asList("0","0","0","0");
        List<String> results =  Arrays.asList("0");
        distinct(data, results);
    }

    @Test public void distinct3() {
        List<String> data =     Arrays.asList("0","1","1","A","2","2","2","B","2","3","3","C","4","4","5");
        List<String> results =  Arrays.asList("0","1","A","2","B","3","C","4","5");
        distinct(data, results);
    }

    private void distinct(List<String> data, List<String> results) {
        // Distinct Iterators are not required to preserve order.
        List<Binding> input = build(data);
        List<Binding> output = build(results);

        QueryIterator qIter = createQueryIter(input);

        List<Binding> iterList = Iter.toList(qIter);
        assertEquals(output.size() , iterList.size(), output+" :: "+iterList);
        // Assume results has no duplicates so same size, same members => order dependent same.
        Set<Binding> testExpected = Set.copyOf(output);
        Set<Binding> testResult = Set.copyOf(iterList);
        assertEquals(testExpected , testResult);

    }

    private void testSame(QueryIterator qIter, List<Binding> data) {
        List<Binding> iterList = Iter.toList(qIter);
        assertEquals(data, iterList);


    }
}

