/*
 * 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.phoenix.compile;

import java.sql.SQLException;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.schema.types.PDataType;

/**
 * Interface used to access the value of a projected column.
 * @since 0.1
 */
public interface ColumnProjector {
  /**
   * Get the column name
   * @return the database column name
   */
  String getName();

  /**
   * Get the expression string
   * @return the label as it was referenced in the query
   */
  String getLabel();

  /**
   * Get the expression
   * @return the expression for the column projector
   */
  public Expression getExpression();

  // TODO: An expression may contain references to multiple tables.
  /**
   * Get the name of the hbase table containing the column
   * @return the hbase table name
   */
  String getTableName();

  /**
   * Get the value of the column, coercing it if necessary to the specified type
   * @param tuple the row containing the column
   * @param type  the type to which to coerce the binary value
   * @param ptr   used to retrieve the value
   * @return the object representation of the column value.
   */
  Object getValue(Tuple tuple, PDataType type, ImmutableBytesWritable ptr) throws SQLException;

  /**
   * Get the value of the column, coercing it if necessary to the specified type
   * @param tuple    the row containing the column
   * @param type     the type to which to coerce the binary value
   * @param ptr      used to retrieve the value
   * @param jdbcType The java type to convert to, for rs.getObject()
   * @return the object representation of the column value.
   */
  Object getValue(Tuple tuple, PDataType type, ImmutableBytesWritable ptr, Class jdbcType)
    throws SQLException;

  boolean isCaseSensitive();
}
