/*
 * Copyright 2016-2020 Crown Copyright
 *
 * Licensed 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 uk.gov.gchq.gaffer.hdfs.operation.handler.job.initialiser;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;

import uk.gov.gchq.gaffer.hdfs.operation.MapReduce;
import uk.gov.gchq.gaffer.store.Store;

import java.io.IOException;
import java.util.Map;

/**
 * A {@link JobInitialiser} that initialises the provided {@link Job} to handle text input data.
 */
public class TextJobInitialiser implements JobInitialiser {

    private static final String MAPPER_GENERATOR = "mapperGenerator";

    public TextJobInitialiser() {
    }

    @Override
    public void initialiseJob(final Job job, final MapReduce operation, final Store store)
            throws IOException {
        initialiseInput(job, operation);
    }

    private void initialiseInput(final Job job, final MapReduce operation) throws IOException {
        job.setInputFormatClass(TextInputFormat.class);

        for (final Map.Entry<String, String> entry : operation.getInputMapperPairs().entrySet()) {
            if (entry.getValue().contains(job.getConfiguration().get(MAPPER_GENERATOR))) {
                TextInputFormat.addInputPath(job, new Path(entry.getKey()));
            }
        }
    }
}
