/*******************************************************************************
t * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.fastlz;

import static org.junit.Assert.fail;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;

import junit.framework.Assert;

import org.junit.BeforeClass;
import org.junit.Test;

/**
 * @author Tuukka Lehtonen
 */
@SuppressWarnings("deprecation")
public class FastLZBasicTests {

    static File testData1;
    static File testData2;
    static File testDataPrime;

    @BeforeClass
    public static void initialize() throws IOException {
        FastLZ.initialize(null);

        testData1 = new File("uncompressed.data");
        writeTestData(testData1, 10000000);
        testData2 = new File("uncompressed-small.data");
        writeTestData(testData2, 100000);
        testDataPrime = new File("uncompressed-prime.data");
        writeTestData(testDataPrime, 1000);

        System.out.println("test data directory: " + testData1.getAbsolutePath());

//        File javaFlz = new File("compressed-prime.data.native.flz");
//        for (int i = 0; i < 100; ++i) {
//            compressFlzJava(testDataPrime, javaFlz);
//        }
    }

    @Test
    public void validateCompress() throws IOException {
        validateCompress(testData1);
    }

    private void validateCompress(File testData) throws IOException {
        System.out.println("==== validateCompress(" + testData.getName() + ") ====");

        File nativeFlz = new File("compressed.data.native.flz");
        long nativeCompressedSize = compressFlzNative(testData, nativeFlz);
        System.out.println("native compressed size: " + nativeCompressedSize);

        // Need to prime JVM JIT by performing multiple passes
        File javaFlz = new File("compressed.data.java.flz");
        long javaCompressedSize = compressFlzJava(testData, javaFlz);
        System.out.println("java compressed size: " + javaCompressedSize);

        Assert.assertEquals(nativeCompressedSize, javaCompressedSize);

        System.out.println("Comparing compressed outputs...");
        compareFiles(nativeFlz, javaFlz);
        System.out.println("Compressed outputs match.");

        File decompressedNativeFlz = new File("decompressed.data.native.flz");
        File decompressedJavaFlz = new File("decompressed.data.java.flz");
        decompressFlzNative(nativeFlz, decompressedNativeFlz);
        decompressFlzNative(javaFlz, decompressedJavaFlz);
        compareFiles(decompressedJavaFlz, decompressedNativeFlz);
        compareFiles(decompressedNativeFlz, testData);
    }

//    @Test
//    public void validateCompressSmall() throws IOException {
//        File nativeFlz = new File("compressed-small.data.native.flz");
//        long nativeCompressedSize = compressFlzNative(testData2, nativeFlz);
//        System.out.println("native compressed size: " + nativeCompressedSize);
//
//        // Need to prime JVM JIT by performing multiple passes
//        File javaFlz = new File("compressed-small.data.java.flz");
//        long javaCompressedSize = compressFlzJava(testData2, javaFlz);
//        System.out.println("java compressed size: " + javaCompressedSize);
//
//        Assert.assertEquals(nativeCompressedSize, javaCompressedSize);
//
//        System.out.println("Comparing compressed outputs...");
//        compareFiles(nativeFlz, javaFlz);
//        System.out.println("Compressed outputs match.");
//    }

//    @Test
//    public void testNativeCompressPerformance() throws IOException {
//        File javaFlz = new File("compressed.data.native.flz");
//        for (int i = 0; i < 5; ++i) {
//            compressFlzNative(testData1, javaFlz);
//        }
//    }
//
//    @Test
//    public void testJavaCompressPerformance() throws IOException {
//        // Need to prime JVM JIT by performing multiple passes
//        File javaFlz = new File("compressed.data.java.flz");
//        for (int i = 0; i < 5; ++i) {
//            compressFlzJava(testData1, javaFlz);
//        }
//    }

//    @Test
//    public void testCompressNative() throws IOException {
//        File flz = new File("compressed.data.native.flz");
//        for (int i = 0; i < 5; ++i) {
//            long compressedSize = compressFlzNative(testData1, flz);
//            System.out.println("native compressed size: " + compressedSize);
//        }
//    }
//
//    @Test
//    public void testCompressionJava() throws IOException {
//        // Need to prime JVM JIT by performing multiple passes
//        File flz = new File("compressed.data.java.flz");
//        for (int i = 0; i < 5; ++i) {
//            long compressedSize = compressFlzJava(testData1, flz);
//            System.out.println("java compressed size: " + compressedSize);
//        }
//    }

    @SuppressWarnings("unused")
    @Test
    public void testDecompress() throws IOException {
        File nativeFlz = new File("compressed.data.native.flz");
        long nativeCompressedSize = compressFlzNative(testData1, nativeFlz);
        System.out.println("native compressed size: " + nativeCompressedSize);

        // Need to prime JVM JIT by performing multiple passes
        File javaFlz = new File("compressed.data.java.flz");
        long javaCompressedSize = compressFlzJava(testData1, javaFlz);
        System.out.println("java compressed size: " + javaCompressedSize);

        Assert.assertEquals(nativeCompressedSize, javaCompressedSize);

        System.out.println("Comparing compressed outputs...");
        compareFiles(nativeFlz, javaFlz);
        System.out.println("Compressed outputs match.");

        File java1 = new File("java-compressed.data.decompressed-with-native");
        long nativeDecompressedSize = decompressFlzNative(javaFlz, java1);
        System.out.println("Comparing native-decompressed output...");
        compareFiles(testData1, java1);
        System.out.println("Native-decompressed output matches original.");

        File java2 = new File("java-compressed.data.decompressed-with-java");
        long javaDecompressedSize = decompressFlzJava(javaFlz, java2);
        System.out.println("Comparing java-decompressed output...");
        compareFiles(testData1, java2);
        System.out.println("Java-decompressed output matches original.");

        for (int i = 0; i < 5; ++i)
            decompressFlz(javaFlz, FastLZ.read(javaFlz), java1, NullOutputStream.INSTANCE);
        for (int i = 0; i < 5; ++i)
            decompressFlz(javaFlz, FastLZJava.read(javaFlz), java2, NullOutputStream.INSTANCE);
    }

    @Test
    public void testDecompressCluster() {
        fail("Not yet implemented");
    }

    static void compareFiles(File file1, File file2) throws IOException {
        InputStream in1 = new BufferedInputStream(new FileInputStream(file1));
        InputStream in2 = new BufferedInputStream(new FileInputStream(file2));
        try {
            int offset = 0;
            while (true) {
                int b1 = in1.read();
                int b2 = in2.read();
                if (b1 == -1 && b2 == -1)
                    return;
                if (b1 == -1)
                    fail("EOF reached in file1 " + file1.getName() + " but not in file2 " + file2.getName());
                if (b2 == -1)
                    fail("EOF reached in file1 " + file1.getName() + " but not in file2 " + file2.getName());
                if (b1 != b2)
                    fail("bytes at offset " + offset + " do not match: " + b1 + " vs. " + b2);
                ++offset;
            }
        } finally {
            in1.close();
            in2.close();
        }
    }

    public static void writeTestData(File file, int rows) throws IOException {
        if (file.exists())
            return;

        System.out.println("writing test data...");
        OutputStream stream = new FileOutputStream(file);
        for (int i = 0; i < rows; ++i)
            stream.write((Integer.toString(i) + "\n").getBytes());
        stream.close();
        System.out.println("wrote " + file.length() + " bytes of test data.");
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long compressFlzJava(File source, File flz) throws IOException {
        return compressFlz(source, flz, FastLZJava.write(flz));
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long compressFlzNative(File source, File flz) throws IOException {
        return compressFlz(source, flz, FastLZ.write(flz));
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long compressFlz(File source, File flz, OutputStream flzOutput) throws IOException {
        System.out.println("compressFlz(" + source + ", " + flz + ")");
        InputStream input = new BufferedInputStream(new FileInputStream(source));
        copy(input, flzOutput);
        input.close();
        flzOutput.close();
        long compressed = flz.length();
        System.out.println("Wrote " + compressed + " compressed bytes");
        return compressed;
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long decompressFlzJava(File flz, File dest) throws IOException {
        return decompressFlz(flz, FastLZJava.read(flz), dest);
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long decompressFlzNative(File flz, File dest) throws IOException {
        return decompressFlz(flz, FastLZ.read(flz), dest);
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long decompressFlz(File source, InputStream flzInput, File dest) throws IOException {
        System.out.println("decompressFlz(" + source + ", " + dest + ")");
        OutputStream output = new BufferedOutputStream(new FileOutputStream(dest));
        copy(flzInput, output);
        flzInput.close();
        output.close();
        long decompressed = dest.length();
        System.out.println("Wrote " + decompressed + " decompressed bytes");
        return decompressed;
    }

    /**
     * @param source
     * @param flz
     * @return compressed size in bytes
     * @throws IOException
     */
    static long decompressFlz(File source, InputStream flzInput, File dest, OutputStream destStream) throws IOException {
        System.out.println("decompressFlz(" + source + ", " + dest + ")");
        copy(flzInput, destStream);
        flzInput.close();
        destStream.close();
        long decompressed = dest.length();
        System.out.println("Wrote " + decompressed + " decompressed bytes");
        return decompressed;
    }

    /**
     * Copy the content of the input stream into the output stream, using a temporary
     * byte array buffer whose size is defined by {@link #IO_BUFFER_SIZE}.
     *
     * @param in The input stream to copy from.
     * @param out The output stream to copy to.
     *
     * @throws IOException If any error occurs during the copy.
     */
    private static final int IO_BUFFER_SIZE = 128 * 1024;

    public static long copy(InputStream in, OutputStream out) throws IOException {
        byte[] b = new byte[IO_BUFFER_SIZE];
        int read;
        long total = 0;
        long start = System.nanoTime();
        while (true) {
            read = in.read(b);
            if (read < 0)
                break;
            total += read;
            //System.out.println("read " + read + " bytes, " + total + " bytes in total");
            out.write(b, 0, read);
        }

        long end = System.nanoTime();
        double totalmb = total/(1024.0*1024.0);
        double time = (end-start)*1e-9;
        double rate = totalmb / time;
        System.out.format("Transferred %d bytes (%.3f Mbytes) in %f seconds (%.3f MB/s)\n", total, totalmb, time, rate);

        return total;
    }

    @SuppressWarnings("unused")
    private boolean checksumsEqual(File f1, File f2) throws IOException {
        byte[] s1 = ChecksumUtil.computeSum(f1);
        byte[] s2 = ChecksumUtil.computeSum(f2);
        return Arrays.equals(s1, s2);
    }

}