/*
    * 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.shardingsphere.sql.parser.sql.common.segment.generic;
  
  import lombok.Getter;
  import lombok.RequiredArgsConstructor;
  import lombok.Setter;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.SQLSegment;
  import org.apache.shardingsphere.sql.parser.sql.common.segment.dml.column.ColumnSegment;
  
  import java.util.Collection;
  import java.util.HashSet;
  
  /**
   * Pivot segment.
   */
  @RequiredArgsConstructor
  @Getter
  public final class PivotSegment implements SQLSegment {
      
      private final int startIndex;
      
      private final int stopIndex;
      
      private final ColumnSegment pivotForColumn;
      
      private final Collection<ColumnSegment> pivotInColumns;
      
      private final boolean isUnPivot;
      
      @Setter
      private ColumnSegment unpivotColumn;
      
      public PivotSegment(final int startIndex, final int stopIndex, final ColumnSegment pivotForColumn, final Collection<ColumnSegment> pivotInColumns) {
          this.startIndex = startIndex;
          this.stopIndex = stopIndex;
          this.pivotForColumn = pivotForColumn;
          this.pivotInColumns = pivotInColumns;
          isUnPivot = false;
      }
      
      /**
       * Get pivot columns.
       * 
       * @return pivot columns
       */
      public Collection<ColumnSegment> getPivotColumns() {
          Collection<ColumnSegment> result = new HashSet<>(pivotInColumns);
          result.add(pivotForColumn);
          if (null != unpivotColumn) {
              result.add(unpivotColumn);
          }
          return result;
      }
  }