///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2002-2012, Industrial Light & Magic, a division of Lucas

// Digital Ltd. LLC

// 

// All rights reserved.

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// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

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// *       Redistributions in binary form must reproduce the above

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///////////////////////////////////////////////////////////////////////////

#include <ImfHuf.h>

#include "ImathRandom.h"

#include <ImfArray.h>

#include <iostream>

#include <exception>

#include <limits.h>

#include <math.h>

#include <stdlib.h>

#include <assert.h>

using namespace OPENEXR_IMF_NAMESPACE;

using namespace std;

namespace {

void

fill1 (unsigned short data[/*n*/], int n, float bias, IMATH_NAMESPACE::Rand48 & rand48)

{

    for (int i = 0; i < n; ++i)

	data[i] = (unsigned short)

		  (pow (rand48.nextf(), double(bias)) * (USHRT_MAX + 1));

}

void

fill2 (unsigned short data[/*n*/], int n, int m, IMATH_NAMESPACE::Rand48 & rand48)

{

    for (int i = 0; i < n; ++i)

	data[i] = 0;

    for (int i = 0; i < m; ++i)

	data[rand48.nexti() % n] = (unsigned short) (rand48.nextf() * (USHRT_MAX + 1));

}

void

fill3 (unsigned short data[/*n*/], int n, int m)

{

    for (int i = 0; i < n; ++i)

	data[i] = m;

}

void

fill4 (unsigned short data[/*n*/], int n)

{

    for (int i = 0; i < n; ++i)

	data[i] = i & USHRT_MAX;

}

void

fill5 (unsigned short data[/*n*/], int n)

{

    for (int i = 0; i < n; ++i)

	data[i] = 0;

    int j = 0, k = 0;

    for (int i = 0; i < n; ++i)

    {

	data[i] = j;

	j = j + k;

	k = k + 1;

	if (j > USHRT_MAX)

	    break;

    }

}

void

compressUncompress (const unsigned short raw[], int n)

{

    Array <char> compressed (3 * n + 4 * 65536);

    Array <unsigned short> uncompressed (n);

    cout << "compressing " << flush;

    int nCompressed = hufCompress (raw, n, compressed);

    cout << "uncompressing " << flush;

    hufUncompress (compressed, nCompressed, uncompressed, n);

    cout << "comparing: " << flush;

    for (int i = 0; i < n; ++i)

	assert (uncompressed[i] == raw[i]);

    cout << sizeof (raw[0]) * n << " bytes, compressed " <<

	    nCompressed  << " bytes" << endl;

}

void

compressUncompressSubset(const unsigned short raw[], int n)

{

    // Test various subsets of the data set

    Array <char> compressed (3 * n + 4 * 65536);

    Array <unsigned short> uncompressed (n);

    int maxOffset = 16;

    if (n <= maxOffset) {

        maxOffset = n-1;

    }

    for (int offset=1; offset

        int maxLength = n - offset;

        int minLength = maxLength - 16;

        if (minLength < 1) minLength = 1;

        for (int length=minLength; length<=maxLength; ++length) {

            cout << "compressing " << flush;

            int nCompressed = hufCompress (raw + offset, length, compressed + offset);

            cout << "uncompressing " << flush;

            hufUncompress (compressed + offset, nCompressed, uncompressed + offset, length);

            for (int i = 0; i < length; ++i)

                assert (uncompressed[offset+i] == raw[offset+i]);

            cout << sizeof (raw[0]) * length << " bytes, compressed " << nCompressed  << " bytes ";

            cout << "(+" << offset << ",-" << n-offset-length << ")" << endl;

        }

    }

}

} // namespace

void

testHuf (const std::string&)

{

    try

    {

	cout << "Testing Huffman encoder" << endl;

	IMATH_NAMESPACE::Rand48 rand48 (0);

	const int N = 1000000;

	Array <unsigned short> raw (N);

	fill1 (raw, N, 1, rand48);	  // test various symbol distributions

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill1 (raw, N, 10, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill1 (raw, N, 100, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill1 (raw, N, 1000, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill2 (raw, N, 1, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill2 (raw, N, 10, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill2 (raw, N, 100, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill2 (raw, N, 1000, rand48);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill3 (raw, N, 0);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill3 (raw, N, 1);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill3 (raw, N, USHRT_MAX - 1);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill3 (raw, N, USHRT_MAX);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill4 (raw, USHRT_MAX + 1);

	compressUncompress (raw, USHRT_MAX + 1);

	compressUncompressSubset (raw, USHRT_MAX + 1);

	fill4 (raw, N);

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	fill4 (raw, 0);

	compressUncompress (raw, 0);	// test small input data sets

	fill4 (raw, 1);

	compressUncompress (raw, 1);

	fill4 (raw, 2);

	compressUncompress (raw, 2);

	fill4 (raw, 3);

	compressUncompress (raw, 3);

	fill5 (raw, N);			// test run-length coding of code table

	compressUncompress (raw, N);

	compressUncompressSubset (raw, N);

	cout << "ok\n" << endl;

    }

    catch (const std::exception &e)

    {

	cerr << "ERROR -- caught exception: " << e.what() << endl;

	assert (false);

    }

}