/*
    *  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.commons.compress.harmony.pack200;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.stream.Stream;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.Arguments;
  import org.junit.jupiter.params.provider.MethodSource;
  
  public class PopulationCodecTest {
  
      static Stream<Arguments> populationCodec() {
          return Stream.of(Arguments.of(new byte[] { 4, 5, 6, 4, 2, 1, 3, 0, 7 }, new long[] { 5, 4, 6, 7 }, Codec.BYTE1),
                  // Codec.SIGNED5 can be trivial for small n, because the encoding is 2n
                  // if even, 2n-1 if odd
                  // Therefore they're left here to explain what the values are :-)
                  Arguments.of(new byte[] { 4 * 2, 4 * 2 - 1, 6 * 2, 4 * 2, 2 * 2, 1 * 2, 3 * 2, 0, 7 * 2 }, new long[] { -4, 4, 6, 7 }, Codec.SIGNED5),
                  Arguments.of(new byte[] { 4 * 2 - 1, 4 * 2, 6 * 2, 4 * 2, 2 * 2, 1 * 2, 3 * 2, 0, 7 * 2 }, new long[] { 4, -4, 6, 7 }, Codec.SIGNED5),
                  Arguments.of(new byte[] { 1, 1, 1 }, new long[] { 1 }, Codec.BYTE1), Arguments.of(new byte[] { 2, 2, 1 }, new long[] { 2 }, Codec.BYTE1),
                  Arguments.of(new byte[] { 1, 1, 2 }, new long[] { -1 }, Codec.SIGNED5),
                  Arguments.of(new byte[] { 2, 2, 0, 1, 3 }, new long[] { 3, 2 }, Codec.BYTE1),
                  Arguments.of(new byte[] { 1, 2, 3, 4, 4, 2, 3, 4, 0, 1 }, new long[] { 2, 3, 4, 1 }, Codec.BYTE1),
                  Arguments.of(new byte[] { 3, 2, 1, 4, 4, 2, 3, 4, 0, 1 }, new long[] { 2, 1, 4, 1 }, Codec.BYTE1),
                  Arguments.of(new byte[] { 3, 2, 1, 4, 1, 2, 3, 4, 0, 1 }, new long[] { 2, 1, 4, 1 }, Codec.BYTE1));
      }
  
      @Test
      public void testEncodeSingleValue() {
          assertThrows(Pack200Exception.class, () -> new PopulationCodec(Codec.SIGNED5, Codec.SIGNED5, Codec.UDELTA5).encode(5),
                  "Should not allow a single value to be encoded as we don't know which codec to use");
          assertThrows(Pack200Exception.class, () -> new PopulationCodec(Codec.SIGNED5, Codec.SIGNED5, Codec.UDELTA5).encode(5, 8),
                  "Should not allow a single value to be encoded as we don't know which codec to use");
      }
  
      @ParameterizedTest
      @MethodSource("populationCodec")
      public void testPopulationCodec(final byte[] data, final long[] expectedResult, final Codec codec) throws IOException, Pack200Exception {
          try (InputStream in = new ByteArrayInputStream(data)) {
              final int[] result = new PopulationCodec(codec, codec, codec).decodeInts(expectedResult.length, in);
              assertEquals(expectedResult.length, result.length);
              for (int i = 0; i < expectedResult.length; i++) {
                  assertEquals(expectedResult[i], result[i]);
              }
              assertEquals(0, in.available());
          }
      }
  
  }