/*
    *  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.
   *  under the License.
   */
  
  package org.apache.commons.imaging.formats.pcx;
  
  import java.io.IOException;
  
  import org.apache.commons.imaging.common.BinaryOutputStream;
  
  final class RleWriter {
      private final boolean isCompressed;
      private int previousByte = -1;
      private int repeatCount;
  
      RleWriter(final boolean isCompressed) {
          this.isCompressed = isCompressed;
      }
  
      void flush(final BinaryOutputStream bos) throws IOException {
          if (repeatCount > 0) {
              if (repeatCount != 1 || (previousByte & 0xc0) == 0xc0) {
                  bos.write(0xc0 | repeatCount);
              }
              bos.write(previousByte);
          }
      }
  
      void write(final BinaryOutputStream bos, final byte[] samples) throws IOException {
          if (isCompressed) {
              for (final byte element : samples) {
                  if ((element & 0xff) == previousByte && repeatCount < 63) {
                      ++repeatCount;
                  } else {
                      if (repeatCount > 0) {
                          if (repeatCount != 1 || (previousByte & 0xc0) == 0xc0) {
                              bos.write(0xc0 | repeatCount);
                          }
                          bos.write(previousByte);
                      }
                      previousByte = 0xff & element;
                      repeatCount = 1;
                  }
              }
          } else {
              bos.write(samples);
          }
      }
  }