/*
 * Copyright ConsenSys AG.
 *
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package org.hyperledger.besu.ethereum.p2p.rlpx.framing;

import static io.netty.buffer.ByteBufUtil.decodeHexDump;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

import java.nio.charset.StandardCharsets;

import org.apache.tuweni.bytes.Bytes;
import org.junit.Test;

public class SnappyCompressorTest {

  private final SnappyCompressor snappy = new SnappyCompressor();

  @Test
  public void roundTrip() {
    String input = "Uncompressed sample text for round-trip compression/decompression";
    input = input + input + input + input; // Give it some repetition for good sample data
    final byte[] data = input.getBytes(StandardCharsets.UTF_8);
    assertThat(snappy.decompress(snappy.compress(data))).isEqualTo(data);
  }

  @Test
  public void roundTripEmptyByteArray() {
    final byte[] data = new byte[0];
    assertThat(snappy.decompress(snappy.compress(data))).isEqualTo(data);
  }

  @Test
  public void compressNull() {
    assertThatThrownBy(() -> snappy.compress(null)).isInstanceOf(NullPointerException.class);
  }

  @Test
  public void decompressNull() {
    assertThatThrownBy(() -> snappy.decompress(null)).isInstanceOf(NullPointerException.class);
  }

  @Test
  public void uncompressedLengthNull() {
    assertThatThrownBy(() -> snappy.uncompressedLength(null))
        .isInstanceOf(NullPointerException.class);
  }

  @Test
  public void shouldDetermineLengthOfEmptyMessage() {
    assertThatThrownBy(() -> snappy.uncompressedLength(new byte[0]))
        .isInstanceOf(FramingException.class);
  }

  @Test
  public void shouldDecompressEmptyMessage() {
    final byte[] compressed = snappy.compress(new byte[0]);
    assertThat(snappy.decompress(compressed)).isEmpty();
  }

  @Test
  public void shouldRejectMessageWithNonZeroDeclaredLengthButNoCompressedData() {
    assertThatThrownBy(() -> snappy.decompress(Bytes.fromHexString("0xFFFFFF01").toArray()))
        .isInstanceOf(FramingException.class);
  }

  @Test
  public void roundTripEthereumData() {
    // First data set.
    byte[] compressed =
        decodeHexDump(
            "ab01a8f8a9f8a74083282fff82945194fc2c4d8f95002c14ed0a7a"
                + "a65102cac9e5953b5e80b844a9059cbb00000015024c3463934897d356b8659cbdfe15209e3bc32291"
                + "05151d3a0100f04a45636408bcb6e0001ca06a4ed94062719ae58d392b253268da005a4fb2d8d33b19"
                + "ec84a7312a34ecbfc2a0055c660cc59f5dad52ae4d6fd5f2fc081d706ee0bce4195ecfff07a1f85d1b"
                + "d6");

    byte[] decompressed =
        decodeHexDump(
            "f8a9f8a74083282fff82945194fc2c4d8f95002c14ed0a7aa651"
                + "02cac9e5953b5e80b844a9059cbb0000000000000000000000003463934897d356b8659cbdfe15209e"
                + "3bc322910500000000000000000000000000000000000000000000000045636408bcb6e0001ca06a4e"
                + "d94062719ae58d392b253268da005a4fb2d8d33b19ec84a7312a34ecbfc2a0055c660cc59f5dad52ae"
                + "4d6fd5f2fc081d706ee0bce4195ecfff07a1f85d1bd6");

    assertThat(snappy.compress(decompressed)).isEqualTo(compressed);
    assertThat(snappy.decompress(compressed)).isEqualTo(decompressed);
    assertThat(snappy.decompress(snappy.compress(decompressed))).isEqualTo(decompressed);
    assertThat(snappy.compress(snappy.decompress(compressed))).isEqualTo(compressed);

    // Second data set.
    compressed =
        decodeHexDump(
            "ac01a8f8aaf8a880843b9aca0082ea609466186008c1050627f979d464eab"
                + "b258860563dbe80b844a9059cbb000019024c7cecb041d044ae699f9830b53256c7e1446430a3191e3"
                + "20100f04b02b5e3af16b188000025a03f691708219e6d099c0c022ac86c6745b98bce1417a94c32d2e"
                + "e5a4e48c0e550a05df314c4202ac2aff5fd13bd5ede29b6967ffdb3063b203c571641fa8dd11c5c");

    decompressed =
        decodeHexDump(
            "f8aaf8a880843b9aca0082ea609466186008c1050627f979d464eabb258"
                + "860563dbe80b844a9059cbb0000000000000000000000007cecb041d044ae699f9830b53256c7e1446"
                + "430a3000000000000000000000000000000000000000000000002b5e3af16b188000025a03f6917082"
                + "19e6d099c0c022ac86c6745b98bce1417a94c32d2ee5a4e48c0e550a05df314c4202ac2aff5fd13bd5"
                + "ede29b6967ffdb3063b203c571641fa8dd11c5c");

    assertThat(snappy.compress(decompressed)).isEqualTo(compressed);
    assertThat(snappy.decompress(compressed)).isEqualTo(decompressed);
    assertThat(snappy.decompress(snappy.compress(decompressed))).isEqualTo(decompressed);
    assertThat(snappy.compress(snappy.decompress(compressed))).isEqualTo(compressed);
  }
}
