/*
    * 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.hadoop.hbase.codec.prefixtree.encode.column;
  
  import java.io.IOException;
  import java.io.OutputStream;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.codec.prefixtree.PrefixTreeBlockMeta;
  import org.apache.hadoop.hbase.codec.prefixtree.encode.other.ColumnNodeType;
  import org.apache.hadoop.hbase.codec.prefixtree.encode.tokenize.TokenizerNode;
  import org.apache.hadoop.hbase.util.ByteRange;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.Strings;
  import org.apache.hadoop.hbase.util.vint.UFIntTool;
  import org.apache.hadoop.hbase.util.vint.UVIntTool;
  
  /**
   * <p>
   * Column nodes can be either family nodes or qualifier nodes, as both sections encode similarly.
   * The family and qualifier sections of the data block are made of 1 or more of these nodes.
   * </p>
   * Each node is composed of 3 sections:<br>
   * <ul>
   * <li>tokenLength: UVInt (normally 1 byte) indicating the number of token bytes
   * <li>token[]: the actual token bytes
   * <li>parentStartPosition: the offset of the next node from the start of the family or qualifier
   * section
   * </ul>
   */
  @InterfaceAudience.Private
  public class ColumnNodeWriter{
  
    /************* fields ****************************/
  
    protected TokenizerNode builderNode;
    protected PrefixTreeBlockMeta blockMeta;
  
    protected int tokenLength;
    protected byte[] token;
    protected int parentStartPosition;
    protected ColumnNodeType nodeType;
  
  
    /*************** construct **************************/
  
    public ColumnNodeWriter(PrefixTreeBlockMeta blockMeta, TokenizerNode builderNode,
        ColumnNodeType nodeType) {
      this.blockMeta = blockMeta;
      this.builderNode = builderNode;
      this.nodeType = nodeType;
      calculateTokenLength();
    }
  
  
    /************* methods *******************************/
  
    public boolean isRoot() {
      return parentStartPosition == 0;
    }
  
    private void calculateTokenLength() {
      tokenLength = builderNode.getTokenLength();
      token = new byte[tokenLength];
    }
  
    /**
     * This method is called before blockMeta.qualifierOffsetWidth is known, so we pass in a
     * placeholder.
     * @param offsetWidthPlaceholder the placeholder
     * @return node width
     */
    public int getWidthUsingPlaceholderForOffsetWidth(int offsetWidthPlaceholder) {
      int width = 0;
      width += UVIntTool.numBytes(tokenLength);
      width += token.length;
      width += offsetWidthPlaceholder;
      return width;
    }
  
    public void writeBytes(OutputStream os) throws IOException {
      int parentOffsetWidth;
      if (this.nodeType == ColumnNodeType.FAMILY) {
       parentOffsetWidth = blockMeta.getFamilyOffsetWidth();
     } else if (this.nodeType == ColumnNodeType.QUALIFIER) {
       parentOffsetWidth = blockMeta.getQualifierOffsetWidth();
     } else {
       parentOffsetWidth = blockMeta.getTagsOffsetWidth();
     }
     UVIntTool.writeBytes(tokenLength, os);
     os.write(token);
     UFIntTool.writeBytes(parentOffsetWidth, parentStartPosition, os);
   }
 
   public void setTokenBytes(ByteRange source) {
     source.deepCopySubRangeTo(0, tokenLength, token, 0);
   }
 
 
   /****************** standard methods ************************/
 
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append(Strings.padFront(builderNode.getOutputArrayOffset() + "", ' ', 3) + ",");
     sb.append("[");
     sb.append(Bytes.toString(token));
     sb.append("]->");
     sb.append(parentStartPosition);
     return sb.toString();
   }
 
 
   /************************** get/set ***********************/
 
   public void setParentStartPosition(int parentStartPosition) {
     this.parentStartPosition = parentStartPosition;
   }
 
 }