/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * 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
 *
 *     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.apache.beam.sdk.extensions.euphoria.core.testkit;

import static org.junit.Assert.assertEquals;

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import org.apache.beam.sdk.extensions.euphoria.core.client.functional.UnaryFunction;
import org.apache.beam.sdk.extensions.euphoria.core.client.functional.UnaryFunctionEnv;
import org.apache.beam.sdk.extensions.euphoria.core.client.operator.MapElements;
import org.apache.beam.sdk.extensions.euphoria.core.testkit.accumulators.SnapshotProvider;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.TypeDescriptor;
import org.apache.beam.sdk.values.TypeDescriptors;
import org.junit.Test;

/** Tests for operator {@code MapElements}. */
public class MapElementsTest extends AbstractOperatorTest {

  @Test
  public void testMapElements() {
    execute(
        new AbstractTestCase<Integer, String>() {

          @Override
          protected PCollection<String> getOutput(PCollection<Integer> input) {
            return MapElements.of(input)
                .using((UnaryFunction<Integer, String>) String::valueOf)
                .output();
          }

          @Override
          protected List<Integer> getInput() {
            return Arrays.asList(1, 2, 3, 4, 5, 6, 7);
          }

          @Override
          protected TypeDescriptor<Integer> getInputType() {
            return TypeDescriptors.integers();
          }

          @Override
          public List<String> getUnorderedOutput() {
            return Arrays.asList("1", "2", "3", "4", "5", "6", "7");
          }
        });
  }

  @Test
  public void testAccumulators() {
    execute(
        new AbstractTestCase<Integer, Integer>() {

          @Override
          protected PCollection<Integer> getOutput(PCollection<Integer> input) {
            return MapElements.named("test")
                .of(input)
                .using(
                    (UnaryFunctionEnv<Integer, Integer>)
                        (x, context) -> {
                          context.getHistogram("dist").add(x, 1);
                          return x;
                        })
                .output();
          }

          @Override
          protected List<Integer> getInput() {
            return Arrays.asList(1, 2, 3, 1, 2, 2, 10, 20, 10);
          }

          @Override
          protected TypeDescriptor<Integer> getInputType() {
            return TypeDescriptors.integers();
          }

          @Override
          public List<Integer> getUnorderedOutput() {
            return Arrays.asList(1, 2, 3, 1, 2, 2, 10, 20, 10);
          }

          @Override
          public void validateAccumulators(SnapshotProvider snapshots) {
            Map<Long, Long> hists = snapshots.getHistogramSnapshots().get("dist");
            assertEquals(5, hists.size());
            assertEquals(Long.valueOf(2), hists.get(1L));
            assertEquals(Long.valueOf(3), hists.get(2L));
            assertEquals(Long.valueOf(1), hists.get(3L));
            assertEquals(Long.valueOf(2), hists.get(10L));
            assertEquals(Long.valueOf(1), hists.get(20L));
          }
        });
  }
}
