/*
    * 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.pnm;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.apache.commons.imaging.ImageFormat;
  import org.apache.commons.imaging.ImageFormats;
  import org.apache.commons.imaging.ImageInfo;
  import org.apache.commons.imaging.ImagingException;
  
  final class PbmFileInfo extends AbstractFileInfo {
      private int bitCache;
      private int bitsInCache;
  
      PbmFileInfo(final int width, final int height, final boolean rawbits) {
          super(width, height, rawbits);
      }
  
      @Override
      public int getBitDepth() {
          return 1;
      }
  
      @Override
      public ImageInfo.ColorType getColorType() {
          return ImageInfo.ColorType.BW;
      }
  
      @Override
      public ImageFormat getImageType() {
          return ImageFormats.PBM;
      }
  
      @Override
      public String getImageTypeDescription() {
          return "PBM: portable bitmap fileformat";
      }
  
      @Override
      public String getMimeType() {
          return "image/x-portable-bitmap";
      }
  
      @Override
      public int getNumComponents() {
          return 1;
      }
  
      @Override
      public int getRgb(final InputStream is) throws IOException {
          if (bitsInCache < 1) {
              final int bits = is.read();
              if (bits < 0) {
                  throw new ImagingException("PBM: Unexpected EOF");
              }
              bitCache = 0xff & bits;
              bitsInCache += 8;
          }
  
          final int bit = 0x1 & bitCache >> 7;
          bitCache <<= 1;
          bitsInCache--;
  
          if (bit == 0) {
              return 0xffffffff;
          }
          if (bit == 1) {
              return 0xff000000;
          }
          throw new ImagingException("PBM: bad bit: " + bit);
      }
  
      @Override
      public int getRgb(final WhiteSpaceReader wsr) throws IOException {
          final int bit = Integer.parseInt(wsr.readtoWhiteSpace());
          if (bit == 0) {
              return 0xff000000;
          }
          if (bit == 1) {
              return 0xffffffff;
          }
          throw new ImagingException("PBM: bad bit: " + bit);
      }
 
     @Override
     public boolean hasAlpha() {
         return false;
     }
 
     @Override
     protected void newline() {
         bitCache = 0;
         bitsInCache = 0;
     }
 
 }