/*
 * 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;
import org.apache.phoenix.schema.SortOrder;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.schema.types.*;

@FunctionParseNode.BuiltInFunction(name = StringToArrayFunction.NAME,
    args = { @FunctionParseNode.Argument(allowedTypes = { PVarchar.class, PChar.class }),
      @FunctionParseNode.Argument(allowedTypes = { PVarchar.class, PChar.class }),
      @FunctionParseNode.Argument(allowedTypes = { PVarchar.class, PChar.class },
          defaultValue = "null") })
public class StringToArrayFunction extends ScalarFunction {
  public static final String NAME = "STRING_TO_ARRAY";

  public StringToArrayFunction() {
  }

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

  @Override
  public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
    Expression delimiterExpr = children.get(1);
    String delimiter;
    if (!delimiterExpr.evaluate(tuple, ptr)) {
      return false;
    } else if (ptr.getLength() == 0) {
      delimiter = "";
    } else {
      delimiter = (String) delimiterExpr.getDataType().toObject(ptr, delimiterExpr.getSortOrder(),
        delimiterExpr.getMaxLength(), delimiterExpr.getScale());
    }

    Expression stringExpr = children.get(0);
    if (!stringExpr.evaluate(tuple, ptr)) {
      return false;
    } else if (ptr.getLength() == 0) {
      return true;
    }
    String string = (String) stringExpr.getDataType().toObject(ptr, stringExpr.getSortOrder(),
      stringExpr.getMaxLength(), stringExpr.getScale());

    Expression nullExpr = children.get(2);
    String nullString = null;
    if (nullExpr.evaluate(tuple, ptr) && ptr.getLength() != 0) {
      nullString = (String) nullExpr.getDataType().toObject(ptr, nullExpr.getSortOrder(),
        nullExpr.getMaxLength(), nullExpr.getScale());
    }

    return PArrayDataType.stringToArray(ptr, string, delimiter, nullString, getSortOrder());
  }

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

  @Override
  public Integer getMaxLength() {
    return null;
  }

  @Override
  public PDataType getDataType() {
    return PVarcharArray.INSTANCE;
  }

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