/*
    * 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.webp;
  
  import static org.apache.commons.imaging.common.BinaryFunctions.read4Bytes;
  import static org.apache.commons.imaging.common.BinaryFunctions.readBytes;
  import static org.apache.commons.imaging.common.BinaryFunctions.skipBytes;
  
  import java.awt.Dimension;
  import java.awt.image.BufferedImage;
  import java.io.Closeable;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.nio.ByteOrder;
  import java.util.ArrayList;
  
  import org.apache.commons.imaging.AbstractImageParser;
  import org.apache.commons.imaging.ImageFormat;
  import org.apache.commons.imaging.ImageFormats;
  import org.apache.commons.imaging.ImageInfo;
  import org.apache.commons.imaging.ImagingException;
  import org.apache.commons.imaging.bytesource.ByteSource;
  import org.apache.commons.imaging.common.XmpEmbeddable;
  import org.apache.commons.imaging.common.XmpImagingParameters;
  import org.apache.commons.imaging.formats.tiff.TiffImageMetadata;
  import org.apache.commons.imaging.formats.tiff.TiffImageParser;
  import org.apache.commons.imaging.formats.webp.chunks.WebPChunk;
  import org.apache.commons.imaging.formats.webp.chunks.WebPChunkVp8;
  import org.apache.commons.imaging.formats.webp.chunks.WebPChunkVp8l;
  import org.apache.commons.imaging.formats.webp.chunks.WebPChunkVp8x;
  import org.apache.commons.imaging.formats.webp.chunks.WebPChunkXml;
  import org.apache.commons.imaging.internal.SafeOperations;
  
  /**
   * WebP image parser.
   *
   * @since 1.0-alpha4
   */
  public class WebPImageParser extends AbstractImageParser<WebPImagingParameters> implements XmpEmbeddable<WebPImagingParameters> {
  
      private static final class ChunksReader implements Closeable {
          private final InputStream is;
          private final WebPChunkType[] chunkTypes;
          private int sizeCount = 4;
          private boolean firstChunk = true;
  
          final int fileSize;
  
          ChunksReader(final ByteSource byteSource) throws IOException, ImagingException {
              this(byteSource, (WebPChunkType[]) null);
          }
  
          ChunksReader(final ByteSource byteSource, final WebPChunkType... chunkTypes) throws ImagingException, IOException {
              this.is = byteSource.getInputStream();
              this.chunkTypes = chunkTypes;
              this.fileSize = readFileHeader(is);
          }
  
          @Override
          public void close() throws IOException {
              is.close();
          }
  
          int getOffset() {
              return SafeOperations.add(sizeCount, 8); // File Header
          }
  
          WebPChunk readChunk() throws ImagingException, IOException {
              while (sizeCount < fileSize) {
                  final int type = read4Bytes("Chunk Type", is, "Not a valid WebP file", ByteOrder.LITTLE_ENDIAN);
                  final int payloadSize = read4Bytes("Chunk Size", is, "Not a valid WebP file", ByteOrder.LITTLE_ENDIAN);
                  if (payloadSize < 0) {
                      throw new ImagingException("Chunk Payload is too long:" + payloadSize);
                  }
                  final boolean padding = payloadSize % 2 != 0;
                  final int chunkSize = SafeOperations.add(8, padding ? 1 : 0, payloadSize);
  
                  if (firstChunk) {
                      firstChunk = false;
                      if (type != WebPChunkType.VP8.value && type != WebPChunkType.VP8L.value && type != WebPChunkType.VP8X.value) {
                          throw new ImagingException("First Chunk must be VP8, VP8L or VP8X");
                      }
                  }
  
                 if (chunkTypes != null) {
                     boolean skip = true;
                     for (final WebPChunkType t : chunkTypes) {
                         if (t.value == type) {
                             skip = false;
                             break;
                         }
                     }
                     if (skip) {
                         skipBytes(is, payloadSize + (padding ? 1 : 0));
                         sizeCount = SafeOperations.add(sizeCount, chunkSize);
                         continue;
                     }
                 }
 
                 final byte[] bytes = readBytes("Chunk Payload", is, payloadSize);
                 final WebPChunk chunk = WebPChunkType.makeChunk(type, payloadSize, bytes);
                 if (padding) {
                     skipBytes(is, 1);
                 }
 
                 sizeCount = SafeOperations.add(sizeCount, chunkSize);
                 return chunk;
             }
 
             if (firstChunk) {
                 throw new ImagingException("No WebP chunks found");
             }
             return null;
         }
     }
 
     private static final String DEFAULT_EXTENSION = ImageFormats.WEBP.getDefaultExtension();
 
     private static final String[] ACCEPTED_EXTENSIONS = ImageFormats.WEBP.getExtensions();
 
     /**
      * Read the file header of WebP file.
      *
      * @return file size in file header (including the WebP signature, excluding the TIFF signature and the file size field).
      */
     private static int readFileHeader(final InputStream is) throws IOException, ImagingException {
         final byte[] buffer = new byte[4];
         if (is.read(buffer) < 4 || !WebPConstants.RIFF_SIGNATURE.equals(buffer)) {
             throw new ImagingException("Not a valid WebP file");
         }
 
         final int fileSize = read4Bytes("File Size", is, "Not a valid WebP file", ByteOrder.LITTLE_ENDIAN);
         if (fileSize < 0) {
             throw new ImagingException("File size is too long:" + fileSize);
         }
 
         if (is.read(buffer) < 4 || !WebPConstants.WEBP_SIGNATURE.equals(buffer)) {
             throw new ImagingException("Not a valid WebP file");
         }
 
         return fileSize;
     }
 
     @Override
     public boolean dumpImageFile(final PrintWriter pw, final ByteSource byteSource) throws ImagingException, IOException {
         pw.println("webp.dumpImageFile");
         try (ChunksReader reader = new ChunksReader(byteSource)) {
             int offset = reader.getOffset();
             WebPChunk chunk = reader.readChunk();
             if (chunk == null) {
                 throw new ImagingException("No WebP chunks found");
             }
 
             // TODO: this does not look too risky; a user could craft an image
             // with millions of chunks, that are really expensive to dump,
             // but that should result in a large image, where we can short-
             // -circuit the operation somewhere else - if needed.
             do {
                 chunk.dump(pw, offset);
 
                 offset = reader.getOffset();
                 chunk = reader.readChunk();
             } while (chunk != null);
         }
         return true;
     }
 
     @Override
     protected String[] getAcceptedExtensions() {
         return ACCEPTED_EXTENSIONS;
     }
 
     @Override
     protected ImageFormat[] getAcceptedTypes() {
         return new ImageFormat[] { ImageFormats.WEBP };
     }
 
     @Override
     public BufferedImage getBufferedImage(final ByteSource byteSource, final WebPImagingParameters params) throws ImagingException, IOException {
         throw new ImagingException("Reading WebP files is currently not supported");
     }
 
     @Override
     public String getDefaultExtension() {
         return DEFAULT_EXTENSION;
     }
 
     @Override
     public WebPImagingParameters getDefaultParameters() {
         return new WebPImagingParameters();
     }
 
     @Override
     public byte[] getIccProfileBytes(final ByteSource byteSource, final WebPImagingParameters params) throws ImagingException, IOException {
         try (ChunksReader reader = new ChunksReader(byteSource, WebPChunkType.ICCP)) {
             final WebPChunk chunk = reader.readChunk();
             return chunk == null ? null : chunk.getBytes();
         }
     }
 
     @Override
     public ImageInfo getImageInfo(final ByteSource byteSource, final WebPImagingParameters params) throws ImagingException, IOException {
         try (ChunksReader reader = new ChunksReader(byteSource, WebPChunkType.VP8, WebPChunkType.VP8L, WebPChunkType.VP8X, WebPChunkType.ANMF)) {
             String formatDetails;
             int width;
             int height;
             int numberOfImages;
             boolean hasAlpha = false;
             ImageInfo.ColorType colorType = ImageInfo.ColorType.RGB;
 
             WebPChunk chunk = reader.readChunk();
             if (chunk instanceof WebPChunkVp8) {
                 formatDetails = "WebP/Lossy";
                 numberOfImages = 1;
 
                 final WebPChunkVp8 vp8 = (WebPChunkVp8) chunk;
                 width = vp8.getWidth();
                 height = vp8.getHeight();
                 colorType = ImageInfo.ColorType.YCbCr;
             } else if (chunk instanceof WebPChunkVp8l) {
                 formatDetails = "WebP/Lossless";
                 numberOfImages = 1;
 
                 final WebPChunkVp8l vp8l = (WebPChunkVp8l) chunk;
                 width = vp8l.getImageWidth();
                 height = vp8l.getImageHeight();
             } else if (chunk instanceof WebPChunkVp8x) {
                 final WebPChunkVp8x vp8x = (WebPChunkVp8x) chunk;
                 width = vp8x.getCanvasWidth();
                 height = vp8x.getCanvasHeight();
                 hasAlpha = ((WebPChunkVp8x) chunk).hasAlpha();
 
                 if (vp8x.hasAnimation()) {
                     formatDetails = "WebP/Animation";
 
                     numberOfImages = 0;
                     while ((chunk = reader.readChunk()) != null) {
                         if (chunk.getType() == WebPChunkType.ANMF.value) {
                             numberOfImages++;
                         }
                     }
 
                 } else {
                     numberOfImages = 1;
                     chunk = reader.readChunk();
 
                     if (chunk == null) {
                         throw new ImagingException("Image has no content");
                     }
 
                     if (chunk.getType() == WebPChunkType.ANMF.value) {
                         throw new ImagingException("Non animated image should not contain ANMF chunks");
                     }
 
                     if (chunk.getType() == WebPChunkType.VP8.value) {
                         formatDetails = "WebP/Lossy (Extended)";
                         colorType = ImageInfo.ColorType.YCbCr;
                     } else if (chunk.getType() == WebPChunkType.VP8L.value) {
                         formatDetails = "WebP/Lossless (Extended)";
                     } else {
                         throw new ImagingException("Unknown WebP chunk type: " + chunk);
                     }
                 }
             } else {
                 throw new ImagingException("Unknown WebP chunk type: " + chunk);
             }
 
             return new ImageInfo(formatDetails, 32, new ArrayList<>(), ImageFormats.WEBP, "webp", height, "image/webp", numberOfImages, -1, -1, -1, -1, width,
                     false, hasAlpha, false, colorType, ImageInfo.CompressionAlgorithm.UNKNOWN);
         }
     }
 
     @Override
     public Dimension getImageSize(final ByteSource byteSource, final WebPImagingParameters params) throws ImagingException, IOException {
         try (ChunksReader reader = new ChunksReader(byteSource)) {
             final WebPChunk chunk = reader.readChunk();
             if (chunk instanceof WebPChunkVp8) {
                 final WebPChunkVp8 vp8 = (WebPChunkVp8) chunk;
                 return new Dimension(vp8.getWidth(), vp8.getHeight());
             }
             if (chunk instanceof WebPChunkVp8l) {
                 final WebPChunkVp8l vp8l = (WebPChunkVp8l) chunk;
                 return new Dimension(vp8l.getImageWidth(), vp8l.getImageHeight());
             }
             if (chunk instanceof WebPChunkVp8x) {
                 final WebPChunkVp8x vp8x = (WebPChunkVp8x) chunk;
                 return new Dimension(vp8x.getCanvasWidth(), vp8x.getCanvasHeight());
             }
             throw new ImagingException("Unknown WebP chunk type: " + chunk);
         }
     }
 
     @Override
     public WebPImageMetadata getMetadata(final ByteSource byteSource, final WebPImagingParameters params) throws ImagingException, IOException {
         try (ChunksReader reader = new ChunksReader(byteSource, WebPChunkType.EXIF)) {
             final WebPChunk chunk = reader.readChunk();
             return chunk == null ? null : new WebPImageMetadata((TiffImageMetadata) new TiffImageParser().getMetadata(chunk.getBytes()));
         }
     }
 
     @Override
     public String getName() {
         return "WebP-Custom";
     }
 
     @Override
     public String getXmpXml(final ByteSource byteSource, final XmpImagingParameters<WebPImagingParameters> params) throws ImagingException, IOException {
         try (ChunksReader reader = new ChunksReader(byteSource, WebPChunkType.XMP)) {
             final WebPChunkXml chunk = (WebPChunkXml) reader.readChunk();
             return chunk == null ? null : chunk.getXml();
         }
     }
 }