/*
 * 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.sql.SQLException;
import java.util.List;
import org.apache.phoenix.compile.StatementContext;
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.ToTimeParseNode;
import org.apache.phoenix.schema.types.PDataType;
import org.apache.phoenix.schema.types.PTime;
import org.apache.phoenix.schema.types.PVarchar;

/**
 * Implementation of the {@code TO_TIME(<string>,[<format-string>,[<timezone-string>]])} built-in
 * function. The second argument is optional and defaults to the phoenix.query.dateFormat value from
 * the HBase config. If present it must be a constant string. The third argument is either a valid
 * (constant) timezone id, or the string "LOCAL". The third argument is also optional, and it
 * defaults to GMT.
 */
@BuiltInFunction(name = ToTimeFunction.NAME, nodeClass = ToTimeParseNode.class,
    args = { @Argument(allowedTypes = { PVarchar.class }),
      @Argument(allowedTypes = { PVarchar.class }, isConstant = true, defaultValue = "null"),
      @Argument(allowedTypes = { PVarchar.class }, isConstant = true, defaultValue = "null") })
public class ToTimeFunction extends ToDateFunction {
  public static final String NAME = "TO_TIME";

  public ToTimeFunction() {
  }

  public ToTimeFunction(List<Expression> children, StatementContext context) throws SQLException {
    super(children, context);
  }

  public ToTimeFunction(List<Expression> children, String dateFormat, String timeZoneId)
    throws SQLException {
    super(children, dateFormat, timeZoneId);
  }

  @Override
  public ToTimeFunction clone(List<Expression> children) {
    try {
      return new ToTimeFunction(children, dateFormat, timeZoneId);
    } catch (Exception e) {
      throw new RuntimeException(e); // Impossible, since it was originally constructed this way
    }
  }

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

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