//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//

#ifdef NDEBUG
#    undef NDEBUG
#endif

#include "compareB44.h"
#include "compareDwa.h"

#include <IlmThread.h>
#include <IlmThreadSemaphore.h>
#include <ImathRandom.h>
#include <ImfArray.h>
#include <ImfRgbaFile.h>
#include <ImfThreading.h>

#include <assert.h>
#include <mutex>
#include <stdio.h>
#include <string>

using namespace OPENEXR_IMF_NAMESPACE;
using namespace std;
using namespace IMATH_NAMESPACE;
using namespace ILMTHREAD_NAMESPACE;

#if ILMTHREAD_THREADING_ENABLED
namespace
{

Rand48     rand1 (27);
std::mutex scanlineMutex;
Semaphore  threadSemaphore;
int        remainingScanlines = 0;

void
fillPixels (Array2D<Rgba>& pixels, int w, int h)
{
    assert (sizeof (int) == sizeof (float));

    for (int y = 0; y < h; ++y)
    {
        for (int x = 0; x < w; ++x)
        {
            Rgba& p = pixels[y][x];

            p.r = x % 100 + 100 * (y % 100) + rand1.nextf (-0.01f, -0.01f);

            p.g = 0.5 + 0.5 * sin (0.1 * x + 0.2 * y) +
                  rand1.nextf (-0.01f, -0.01f);

            p.b = 0.5 + 0.5 * sin (0.1 * x + 0.3 * y) +
                  rand1.nextf (-0.01f, -0.01f);

            p.a = rand1.nextf (0.0f, 1.0f);
        }
    }
}

class WriterThread : public Thread
{
public:
    WriterThread (RgbaOutputFile* outfile);

    virtual void run ();

private:
    RgbaOutputFile* _outfile;
};

WriterThread::WriterThread (RgbaOutputFile* outfile) : _outfile (outfile)
{
    start ();
}

void
WriterThread::run ()
{

    while (true)
    {
        std::lock_guard<std::mutex> lock (scanlineMutex);

        if (remainingScanlines)
        {
            int n = int (rand1.nextf (0.0f, remainingScanlines) + 0.5f);
            _outfile->writePixels (n);
            remainingScanlines -= n;
        }
        else
        {
            break;
        }
    }

    //
    // Signal that the thread has finished
    //

    threadSemaphore.post ();
}

class ReaderThread : public Thread
{
public:
    ReaderThread (RgbaInputFile* infile, int start, int step);

    virtual void run ();

private:
    RgbaInputFile* _infile;
    int            _start;
    int            _step;
};

ReaderThread::ReaderThread (RgbaInputFile* infile, int start, int step)
    : _infile (infile), _start (start), _step (step)
{
    Thread::start ();
}

void
ReaderThread::run ()
{

    int num = _infile->header ().dataWindow ().max.y -
              _infile->header ().dataWindow ().min.y + 1;

    for (int i = _start; i < num; i += _step)
        _infile->readPixels (i);

    //
    // Signal that the thread has finished
    //

    threadSemaphore.post ();
}

void
writeReadRGBA (
    const char           fileName[],
    int                  width,
    int                  height,
    const Array2D<Rgba>& p1,
    RgbaChannels         channels,
    Compression          comp)
{
    //
    // Save the selected channels of RGBA image p1; save the
    // scan lines in the specified order.  Read the image back
    // from the file, and compare the data with the original.
    //

    cout << "channels " << ((channels & WRITE_R) ? "R" : "")
         << ((channels & WRITE_G) ? "G" : "")
         << ((channels & WRITE_B) ? "B" : "")
         << ((channels & WRITE_A) ? "A" : "") << ", compression " << comp
         << ", " << flush;

    Header header (width, height);
    header.compression () = comp;

    {
        remove (fileName);
        cout << "writing " << flush;
        RgbaOutputFile out (fileName, header, channels);
        out.setFrameBuffer (&p1[0][0], 1, width);

        remainingScanlines = height;
        WriterThread writer1 (&out);
        WriterThread writer2 (&out);
        threadSemaphore.wait ();
        threadSemaphore.wait ();
    }

    {
        cout << "reading " << flush;
        RgbaInputFile in (fileName);
        const Box2i&  dw = in.dataWindow ();

        int w  = dw.max.x - dw.min.x + 1;
        int h  = dw.max.y - dw.min.y + 1;
        int dx = dw.min.x;
        int dy = dw.min.y;

        Array2D<Rgba> p2 (h, w);
        in.setFrameBuffer (&p2[-dy][-dx], 1, w);

        {
            ReaderThread reader1 (&in, 0, 2);
            ReaderThread reader2 (&in, 1, 2);
            threadSemaphore.wait ();
            threadSemaphore.wait ();
        }

        assert (in.displayWindow () == header.displayWindow ());
        assert (in.dataWindow () == header.dataWindow ());
        assert (in.pixelAspectRatio () == header.pixelAspectRatio ());
        assert (in.screenWindowCenter () == header.screenWindowCenter ());
        assert (in.screenWindowWidth () == header.screenWindowWidth ());
        assert (in.lineOrder () == header.lineOrder ());
        assert (in.compression () == header.compression ());
        assert (in.channels () == channels);

        cout << "comparing " << endl;

        if (in.compression () == B44_COMPRESSION ||
            in.compression () == B44A_COMPRESSION)
        {
            compareB44 (width, height, p1, p2, channels);
        }
        else if (
            in.compression () == DWAA_COMPRESSION ||
            in.compression () == DWAB_COMPRESSION)
        {
            compareDwa (width, height, p1, p2, channels);
        }
        else
        {
            for (int y = 0; y < h; ++y)
            {
                for (int x = 0; x < w; ++x)
                {
                    if (channels & WRITE_R)
                        assert (p2[y][x].r == p1[y][x].r);
                    else
                        assert (p2[y][x].r == 0);

                    if (channels & WRITE_G)
                        assert (p2[y][x].g == p1[y][x].g);
                    else
                        assert (p2[y][x].g == 0);

                    if (channels & WRITE_B)
                        assert (p2[y][x].b == p1[y][x].b);
                    else
                        assert (p2[y][x].b == 0);

                    if (channels & WRITE_A)
                        assert (p2[y][x].a == p1[y][x].a);
                    else
                        assert (p2[y][x].a == 1);
                }
            }
        }
    }

    remove (fileName);
}

} // namespace
#endif

void
testSharedFrameBuffer (const std::string& tempDir)
{
    try
    {
        cout << "Testing reading from and writing to files using\n"
                "multiple threads and a shared framebuffer"
             << endl;

        if (!ILMTHREAD_NAMESPACE::supportsThreads ())
        {
            cout << "   Threading not supported!" << endl << endl;
            return;
        }

#if ILMTHREAD_THREADING_ENABLED
        const int W = 1371;
        const int H = 159;

        Array2D<Rgba> p1 (H, W);
        fillPixels (p1, W, H);

        for (int n = 0; n <= 8; n++)
        {
            int numThreads = (n * 3) % 8;

            setGlobalThreadCount (numThreads);
            cout << "number of threads: " << globalThreadCount () << endl;

            for (int comp = 0; comp < NUM_COMPRESSION_METHODS; ++comp)
            {
                writeReadRGBA (
                    (tempDir + "imf_test_rgba.exr").c_str (),
                    W,
                    H,
                    p1,
                    WRITE_RGBA,
                    Compression (comp));

                writeReadRGBA (
                    (tempDir + "imf_test_rgba.exr").c_str (),
                    W,
                    H,
                    p1,
                    WRITE_RGB,
                    Compression (comp));

                writeReadRGBA (
                    (tempDir + "imf_test_rgba.exr").c_str (),
                    W,
                    H,
                    p1,
                    WRITE_A,
                    Compression (comp));

                writeReadRGBA (
                    (tempDir + "imf_test_rgba.exr").c_str (),
                    W,
                    H,
                    p1,
                    RgbaChannels (WRITE_R | WRITE_B),
                    Compression (comp));
            }
        }
#endif
        cout << "ok\n" << endl;
    }
    catch (const std::exception& e)
    {
        cerr << "ERROR -- caught exception: " << e.what () << endl;
        assert (false);
    }
}
