/*
 * 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.expression.function;

import java.util.List;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.parse.FunctionParseNode.Argument;
import org.apache.phoenix.parse.FunctionParseNode.BuiltInFunction;
import org.apache.phoenix.parse.ParseException;
import org.apache.phoenix.schema.SortOrder;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.schema.types.PArrayDataTypeDecoder;
import org.apache.phoenix.schema.types.PBinaryArray;
import org.apache.phoenix.schema.types.PDataType;
import org.apache.phoenix.schema.types.PInteger;
import org.apache.phoenix.schema.types.PVarbinaryArray;

@BuiltInFunction(name = ArrayIndexFunction.NAME,
    args = { @Argument(allowedTypes = { PBinaryArray.class, PVarbinaryArray.class }),
      @Argument(allowedTypes = { PInteger.class }) })
public class ArrayIndexFunction extends ScalarFunction {

  public static final String NAME = "ARRAY_ELEM";

  public ArrayIndexFunction() {
  }

  public ArrayIndexFunction(List<Expression> children) {
    super(children);
  }

  @Override
  public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
    Expression indexExpr = children.get(1);
    if (!indexExpr.evaluate(tuple, ptr)) {
      return false;
    } else if (ptr.getLength() == 0) {
      return true;
    }
    // Use Codec to prevent Integer object allocation
    int index = PInteger.INSTANCE.getCodec().decodeInt(ptr, indexExpr.getSortOrder());
    if (index < 0) {
      throw new ParseException("Index cannot be negative :" + index);
    }
    Expression arrayExpr = children.get(0);
    return PArrayDataTypeDecoder.positionAtArrayElement(tuple, ptr, index, arrayExpr, getDataType(),
      getMaxLength());
  }

  @Override
  public PDataType getDataType() {
    return PDataType
      .fromTypeId(children.get(0).getDataType().getSqlType() - PDataType.ARRAY_TYPE_BASE);
  }

  @Override
  public Integer getMaxLength() {
    return this.children.get(0).getMaxLength();
  }

  @Override
  public String getName() {
    return NAME;
  }

  @Override
  public SortOrder getSortOrder() {
    return this.children.get(0).getSortOrder();
  }

}
