/**
 * 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.pig.builtin;

import java.io.IOException;

import org.apache.pig.EvalFunc;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

/**
 * This method should never be used directly, use {@link ToDate}.
 */
public class ToDate3ARGS extends EvalFunc<DateTime> {

    public DateTime exec(Tuple input) throws IOException {
        if (input == null || input.size() < 1 || input.get(0) == null) {
            return null;
        }
        DateTimeFormatter dtf = DateTimeFormat.forPattern(DataType
                .toString(input.get(1)));
        DateTimeZone dtz = DateTimeZone.forOffsetMillis(DateTimeZone.forID(
                DataType.toString(input.get(2))).getOffset(null));
        return dtf.withZone(dtz).parseDateTime(DataType.toString(input.get(0)));
    }

    @Override
    public boolean allowCompileTimeCalculation() {
        return true;
    }
}