content: /*
   * Copyright 2008 ZXing authors
   *
   * 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.ailiwean.core.zxing.core.datamatrix.decoder;
  
  
  /**
   * <p>Encapsulates a block of data within a Data Matrix Code. Data Matrix Codes may split their data into
   * multiple blocks, each of which is a unit of data and error-correction codewords. Each
   * is represented by an instance of this class.</p>
   *
   * @author bbrown@google.com (Brian Brown)
   */
  final class DataBlock {
  
    private final int numDataCodewords;
    private final byte[] codewords;
  
    private DataBlock(int numDataCodewords, byte[] codewords) {
      this.numDataCodewords = numDataCodewords;
      this.codewords = codewords;
    }
  
    /**
     * <p>When Data Matrix Codes use multiple data blocks, they actually interleave the bytes of each of them.
     * That is, the first byte of data block 1 to n is written, then the second bytes, and so on. This
     * method will separate the data into original blocks.</p>
     *
     * @param rawCodewords bytes as read directly from the Data Matrix Code
     * @param version version of the Data Matrix Code
     * @return DataBlocks containing original bytes, "de-interleaved" from representation in the
     *         Data Matrix Code
     */
    static DataBlock[] getDataBlocks(byte[] rawCodewords,
                                     Version version) {
      // Figure out the number and size of data blocks used by this version
      Version.ECBlocks ecBlocks = version.getECBlocks();
  
      // First count the total number of data blocks
      int totalBlocks = 0;
      Version.ECB[] ecBlockArray = ecBlocks.getECBlocks();
      for (Version.ECB ecBlock : ecBlockArray) {
         totalBlocks += ecBlock.getCount();
      }
  
      // Now establish DataBlocks of the appropriate size and number of data codewords
      DataBlock[] result = new DataBlock[totalBlocks];
      int numResultBlocks = 0;
      for (Version.ECB ecBlock : ecBlockArray) {
        for (int i = 0; i < ecBlock.getCount(); i++) {
          int numDataCodewords = ecBlock.getDataCodewords();
          int numBlockCodewords = ecBlocks.getECCodewords() + numDataCodewords;
          result[numResultBlocks++] = new DataBlock(numDataCodewords, new byte[numBlockCodewords]);
        }
      }
  
      // All blocks have the same amount of data, except that the last n
      // (where n may be 0) have 1 less byte. Figure out where these start.
      // TODO(bbrown): There is only one case where there is a difference for Data Matrix for size 144
      int longerBlocksTotalCodewords = result[0].codewords.length;
      //int shorterBlocksTotalCodewords = longerBlocksTotalCodewords - 1;
  
      int longerBlocksNumDataCodewords = longerBlocksTotalCodewords - ecBlocks.getECCodewords();
      int shorterBlocksNumDataCodewords = longerBlocksNumDataCodewords - 1;
      // The last elements of result may be 1 element shorter for 144 matrix
      // first fill out as many elements as all of them have minus 1
      int rawCodewordsOffset = 0;
      for (int i = 0; i < shorterBlocksNumDataCodewords; i++) {
        for (int j = 0; j < numResultBlocks; j++) {
          result[j].codewords[i] = rawCodewords[rawCodewordsOffset++];
        }
      }
  
      // Fill out the last data block in the longer ones
      boolean specialVersion = version.getVersionNumber() == 24;
      int numLongerBlocks = specialVersion ? 8 : numResultBlocks;
      for (int j = 0; j < numLongerBlocks; j++) {
        result[j].codewords[longerBlocksNumDataCodewords - 1] = rawCodewords[rawCodewordsOffset++];
      }
  
      // Now add in error correction blocks
      int max = result[0].codewords.length;
      for (int i = longerBlocksNumDataCodewords; i < max; i++) {
        for (int j = 0; j < numResultBlocks; j++) {
          int jOffset = specialVersion ? (j + 8) % numResultBlocks : j;
          int iOffset = specialVersion && jOffset > 7 ? i - 1 : i;
          result[jOffset].codewords[iOffset] = rawCodewords[rawCodewordsOffset++];
        }
      }
  
      if (rawCodewordsOffset != rawCodewords.length) {
        throw new IllegalArgumentException();
      }
  
      return result;
    }
  
    int getNumDataCodewords() {
      return numDataCodewords;
    }
  
    byte[] getCodewords() {
      return codewords;
    }
  
  }
  