/*
    * 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.imaging.formats.png;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.awt.image.BufferedImage;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.IOException;
  
  import org.apache.commons.imaging.Imaging;
  import org.apache.commons.imaging.ImagingTestConstants;
  import org.apache.commons.imaging.palette.Palette;
  import org.apache.commons.imaging.palette.PaletteFactory;
  import org.apache.commons.imaging.palette.SimplePalette;
  import org.junit.jupiter.api.Test;
  
  /**
   * Unit tests for class {@link PngWriter}.
   */
  public class PngWriterTest extends AbstractPngTest {
  
      // The form of the test set is
      // 0. target file name
      // 1. Expected colour count (as String) - for testPaletteFactory
      private static String[][] testSet = { { "1/Oregon Scientific DS6639 - DSC_0307 - small.png", "1" }, { "2/12118.png", "1" }, { "2/28569-4.png", "1" },
              { "2/28569-8.png", "1" }, { "2/28569.png", "1" }, { "3/testImage.png", "116" }, { "3/testImageNoAlpha.png", "1" },
              { "4/buttons_level_menu_down.ipad.png", "2" }, { "5/trns-gray.png", "26" }, { "5/trns-palette8.png", "18" }, { "5/trns-rgb.png", "26" }, };
  
      private static int countColors(final byte[] bytes) throws IOException {
          final BufferedImage imageParsed = Imaging.getBufferedImage(bytes);
          return new PaletteFactory().makeExactRgbPaletteSimple(imageParsed, Integer.MAX_VALUE).length();
      }
  
      private static byte[] getImageBytes(final BufferedImage image, final PngImagingParameters params, final PaletteFactory paletteFactory) throws IOException {
          try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
              new PngWriter().writeImage(image, os, params, paletteFactory);
              return os.toByteArray();
          }
      }
  
      private File getPngFile(final String name) {
          final File pngFolder = new File(ImagingTestConstants.TEST_IMAGE_FOLDER, "png");
          return new File(pngFolder, name);
      }
  
      @Test
      public void testNullParameters() throws IOException {
          for (final String[] testTarget : testSet) {
              final String filePath = testTarget[0];
              final File imageFile = getPngFile(filePath);
  
              final BufferedImage image = Imaging.getBufferedImage(imageFile);
  
              try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
                  new PngWriter().writeImage(image, os, null, null);
                  final byte[] bytes = os.toByteArray();
                  final int numColors = countColors(bytes);
                  assertTrue(numColors > 1);
              }
          }
      }
  
      @Test
      public void testPaletteFactory() throws IOException {
          for (final String[] testTarget : testSet) {
              final String filePath = testTarget[0];
              final File imageFile = getPngFile(filePath);
              final int colourCount = Integer.parseInt(testTarget[1]);
  
              final BufferedImage image = Imaging.getBufferedImage(imageFile);
              final PngImagingParameters params = new PngImagingParameters();
              params.setForceIndexedColor(true);
  
              final byte[] bytes = getImageBytes(image, params, null);
              final int numColors = countColors(bytes);
              assertTrue(numColors > 1, imageFile::toString);
  
              final PaletteFactory factory = new PaletteFactory() {
                  @Override
                  public Palette makeQuantizedRgbPalette(final BufferedImage src, final int max) {
                      // Force a palette containing nothing but black (all zero's).
                      return new SimplePalette(new int[max]);
                 }
             };
             final byte[] palettedBytes = getImageBytes(image, params, factory);
             assertEquals(colourCount, countColors(palettedBytes), filePath);
         }
     }
 }