// Copyright 2015 The Bazel Authors. All rights reserved.
//
// 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 com.google.devtools.build.android.ziputils;

import static com.google.common.truth.Truth.assertWithMessage;
import static com.google.devtools.build.android.ziputils.DataDescriptor.EXTCRC;
import static com.google.devtools.build.android.ziputils.DataDescriptor.EXTLEN;
import static com.google.devtools.build.android.ziputils.DataDescriptor.EXTSIG;
import static com.google.devtools.build.android.ziputils.DataDescriptor.EXTSIZ;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.zip.ZipInputStream;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Unit tests for {@link DataDescriptor}. */
@RunWith(JUnit4.class)
public class DataDescriptorTest {

  /**
   * Test of viewOf method, of class DataDescriptor.
   */
  @Test
  public void testViewOf() {
    int[] markers = { 12345678, DataDescriptor.SIGNATURE, 0};
    for (int marker : markers) {
      ByteBuffer buffer = ByteBuffer.allocate(50).order(ByteOrder.LITTLE_ENDIAN);
      for (int i = 0; i < 50; i++) {
        buffer.put((byte) i);
      }
      int offset = 20;
      buffer.putInt(offset, marker);
      buffer.position(offset);
      DataDescriptor view = DataDescriptor.viewOf(buffer);
      int expMark = marker == DataDescriptor.SIGNATURE ? (int) ZipInputStream.EXTSIG : -1;
      int expSize = marker == DataDescriptor.SIGNATURE ? ZipInputStream.EXTHDR
          : ZipInputStream.EXTHDR - 4;
      int expPos = 0;
      assertWithMessage("not based at current position[" + marker + "]")
          .that(view.get(EXTSIG))
          .isEqualTo(expMark);
      assertWithMessage("Not slice with position 0[" + marker + "]")
          .that(view.buffer.position())
          .isEqualTo(expPos);
      assertWithMessage("Not sized with comment[" + marker + "]")
          .that(view.getSize())
          .isEqualTo(expSize);
      assertWithMessage("Not limited to size[" + marker + "]")
          .that(view.buffer.limit())
          .isEqualTo(expSize);
    }
  }

  /**
   * Test of view method, of class DataDescriptor.
   */
  @Test
  public void testView_0args() {
    DataDescriptor view = DataDescriptor.allocate();
    int expSize = ZipInputStream.EXTHDR;
    int expPos = 0;
    int expMarker = (int) ZipInputStream.EXTSIG;
    assertWithMessage("no marker").that(view.hasMarker()).isTrue();
    assertWithMessage("No marker").that(view.get(EXTSIG)).isEqualTo(expMarker);
    assertWithMessage("Not at position 0").that(view.buffer.position()).isEqualTo(expPos);
    assertWithMessage("Not sized correctly").that(view.getSize()).isEqualTo(expSize);
    assertWithMessage("Not limited to size").that(view.buffer.limit()).isEqualTo(expSize);
  }

  /**
   * Test of view method, of class DataDescriptor.
   */
  @Test
  public void testView_ByteBuffer() {
    ByteBuffer buffer = ByteBuffer.allocate(100).order(ByteOrder.LITTLE_ENDIAN);
    for (int i = 0; i < 100; i++) {
      buffer.put((byte) i);
    }
    buffer.position(50);
    DataDescriptor view = DataDescriptor.view(buffer);
    int expMark = (int) ZipInputStream.EXTSIG;
    int expSize = ZipInputStream.EXTHDR;
    int expPos = 0;
    assertWithMessage("not based at current position").that(view.get(EXTSIG)).isEqualTo(expMark);
    assertWithMessage("Not slice with position 0").that(view.buffer.position()).isEqualTo(expPos);
    assertWithMessage("Not sized with comment").that(view.getSize()).isEqualTo(expSize);
    assertWithMessage("Not limited to size").that(view.buffer.limit()).isEqualTo(expSize);
  }

  /**
   * Test of copy method, of class DataDescriptor.
   */
  @Test
  public void testCopy() {
    ByteBuffer buffer = ByteBuffer.allocate(100).order(ByteOrder.LITTLE_ENDIAN);
    DataDescriptor view = DataDescriptor.allocate();
    view.copy(buffer);
    int expSize = view.getSize();
    assertWithMessage("buffer not advanced as expected").that(buffer.position()).isEqualTo(expSize);
    buffer.position(0);
    DataDescriptor clone = DataDescriptor.viewOf(buffer);
    assertWithMessage("Fail to copy mark").that(clone.get(EXTSIG)).isEqualTo(view.get(EXTSIG));
  }

  /**
   * Test of with and get methods.
   */
  @Test
  public void testWithAndGetMethods() {
    int crc = 0x12345678;
    int compressed = 0x357f1d5;
    int uncompressed = 0x74813159;
    DataDescriptor view = DataDescriptor.allocate()
        .set(EXTCRC, crc)
        .set(EXTSIZ, compressed)
        .set(EXTLEN, uncompressed);
    assertWithMessage("CRC").that(view.get(EXTCRC)).isEqualTo(crc);
    assertWithMessage("Compressed size").that(view.get(EXTSIZ)).isEqualTo(compressed);
    assertWithMessage("Uncompressed size").that(view.get(EXTLEN)).isEqualTo(uncompressed);
  }
}