package voldemort.store.readonly.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.zip.GZIPInputStream;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.BytesWritable;

import voldemort.TestUtils;
import voldemort.VoldemortException;
import voldemort.utils.ByteUtils;


public class ReadOnlyTestUtils {

    /**
     * Determines if two binary files are equal
     * 
     * @param fileA
     * @param fileB
     * @return
     * @throws IOException
     */
    public static boolean areTwoBinaryFilesEqual(File fileA, File fileB) throws IOException {
        // compare file sizes
        if(fileA.length() != fileB.length())
            return false;

        // read and compare bytes pair-wise
        InputStream inputStream1 = new FileInputStream(fileA);
        InputStream inputStream2 = new FileInputStream(fileB);
        int nextByteFromInput1, nextByteFromInput2;
        do {
            nextByteFromInput1 = inputStream1.read();
            nextByteFromInput2 = inputStream2.read();
        } while(nextByteFromInput1 == nextByteFromInput2 && nextByteFromInput1 != -1);
        inputStream1.close();
        inputStream2.close();

        // true only if end of file is reached
        return nextByteFromInput1 == -1;
    }

    /**
     * Un gzip the compressedFile to the given decompressedFile
     * 
     * @param compressedFile
     * @param decompressedFile
     */
    public static void unGunzipFile(String compressedFile, String decompressedFile) {

        byte[] buffer = new byte[1024];
        try {
            FileSystem fs = FileSystem.getLocal(new Configuration());
            FSDataInputStream fileIn = fs.open(new Path(compressedFile));
            GZIPInputStream gZIPInputStream = new GZIPInputStream(fileIn);
            FileOutputStream fileOutputStream = new FileOutputStream(decompressedFile);
            int bytes_read;
            while((bytes_read = gZIPInputStream.read(buffer)) > 0) {
                fileOutputStream.write(buffer, 0, bytes_read);
            }
            gZIPInputStream.close();
            fileOutputStream.close();

        } catch(IOException ex) {
            throw new VoldemortException("Got IOException while trying to un-gzip file: " + compressedFile, ex);
        }
    }
}