CsvEventStreamReaderTimedTypedCsvReader.java

package com.ldbc.driver.generator;


import com.ldbc.driver.util.Function1;

import java.util.Arrays;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;

import static java.lang.String.format;


public class CsvEventStreamReaderTimedTypedCsvReader<BASE_EVENT_TYPE, DECODER_KEY_TYPE>
        implements Iterator<BASE_EVENT_TYPE>
{
    private final Map<DECODER_KEY_TYPE,EventDecoder<BASE_EVENT_TYPE>> decoders;
    private final Iterator<String[]> csvRowIterator;
    private final Function1<String[],DECODER_KEY_TYPE,RuntimeException> decoderKeyExtractor;

    public CsvEventStreamReaderTimedTypedCsvReader( Iterator<String[]> csvRowIterator,
            Map<DECODER_KEY_TYPE,EventDecoder<BASE_EVENT_TYPE>> decoders,
            Function1<String[],DECODER_KEY_TYPE,RuntimeException> decoderKeyExtractor )
    {
        this.csvRowIterator = csvRowIterator;
        this.decoders = decoders;
        this.decoderKeyExtractor = decoderKeyExtractor;
    }

    @Override
    public boolean hasNext()
    {
        return csvRowIterator.hasNext();
    }

    @Override
    public BASE_EVENT_TYPE next()
    {
        String[] csvRow = csvRowIterator.next();
        DECODER_KEY_TYPE decoderKey = decoderKeyExtractor.apply( csvRow );
        EventDecoder<BASE_EVENT_TYPE> decoder = decoders.get( decoderKey );
        if ( null == decoder )
        {
            throw new NoSuchElementException( format(
                    "No decoder found that matches this column\nROW: %s\nDECODER KEY: %s",
                    Arrays.toString( csvRow ),
                    decoderKey
            ) );
        }
        return decoder.decodeEvent( csvRow );
    }

    @Override
    public void remove()
    {
        throw new UnsupportedOperationException( format( "%s does not support remove()", getClass().getSimpleName() ) );
    }


    public static interface EventDecoder<BASE_EVENT_TYPE>
    {
        BASE_EVENT_TYPE decodeEvent( String[] csvRow );
    }
}