/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4365)

namespace jpeglibNamespace
{
#if JUCE_INCLUDE_JPEGLIB_CODE || ! defined (JUCE_INCLUDE_JPEGLIB_CODE)
    #if JUCE_MINGW
     typedef unsigned char boolean;
    #endif

     JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wconversion",
                                          "-Wdeprecated-register",
                                          "-Wdeprecated-declarations",
                                          "-Wsign-conversion",
                                          "-Wcast-align",
                                          "-Wswitch-enum",
                                          "-Wswitch-default",
                                          "-Wimplicit-fallthrough",
                                          "-Wzero-as-null-pointer-constant",
                                          "-Wshift-negative-value",
                                          "-Wcomma")

    #define JPEG_INTERNALS
    #undef FAR
    #include "jpglib/jpeglib.h"

    #include "jpglib/jcapimin.c"
    #include "jpglib/jcapistd.c"
    #include "jpglib/jccoefct.c"
    #include "jpglib/jccolor.c"
    #undef FIX
    #include "jpglib/jcdctmgr.c"
    #undef CONST_BITS
    #include "jpglib/jchuff.c"
    #undef emit_byte
    #include "jpglib/jcinit.c"
    #include "jpglib/jcmainct.c"
    #include "jpglib/jcmarker.c"
    #include "jpglib/jcmaster.c"
    #include "jpglib/jcomapi.c"
    #include "jpglib/jcparam.c"
    #include "jpglib/jcphuff.c"
    #include "jpglib/jcprepct.c"
    #include "jpglib/jcsample.c"
    #include "jpglib/jctrans.c"
    #include "jpglib/jdapistd.c"
    #include "jpglib/jdapimin.c"
    #include "jpglib/jdatasrc.c"
    #include "jpglib/jdcoefct.c"
    #undef FIX
    #include "jpglib/jdcolor.c"
    #undef FIX
    #include "jpglib/jddctmgr.c"
    #undef CONST_BITS
    #undef ASSIGN_STATE
    #include "jpglib/jdhuff.c"
    #include "jpglib/jdinput.c"
    #include "jpglib/jdmainct.c"
    #include "jpglib/jdmarker.c"
    #include "jpglib/jdmaster.c"
    #undef FIX
    #include "jpglib/jdmerge.c"
    #undef ASSIGN_STATE
    #include "jpglib/jdphuff.c"
    #include "jpglib/jdpostct.c"
    #undef FIX
    #include "jpglib/jdsample.c"
    #include "jpglib/jdtrans.c"
    #include "jpglib/jfdctflt.c"
    #include "jpglib/jfdctint.c"
    #undef CONST_BITS
    #undef MULTIPLY
    #undef FIX_0_541196100
    #include "jpglib/jfdctfst.c"
    #undef FIX_0_541196100
    #include "jpglib/jidctflt.c"
    #undef CONST_BITS
    #undef FIX_1_847759065
    #undef MULTIPLY
    #undef DEQUANTIZE
    #undef DESCALE
    #include "jpglib/jidctfst.c"
    #undef CONST_BITS
    #undef FIX_1_847759065
    #undef MULTIPLY
    #undef DEQUANTIZE
    #include "jpglib/jidctint.c"
    #include "jpglib/jidctred.c"
    #include "jpglib/jmemmgr.c"
    #include "jpglib/jmemnobs.c"
    #include "jpglib/jquant1.c"
    #include "jpglib/jquant2.c"
    #include "jpglib/jutils.c"
    #include "jpglib/transupp.c"

    JUCE_END_IGNORE_WARNINGS_GCC_LIKE
#else
    #define JPEG_INTERNALS
    #undef FAR
    #include <jpeglib.h>
#endif
}

#undef max
#undef min

JUCE_END_IGNORE_WARNINGS_MSVC

//==============================================================================
namespace JPEGHelpers
{
    using namespace jpeglibNamespace;

   #if ! (JUCE_WINDOWS && (JUCE_MSVC || JUCE_CLANG))
    using jpeglibNamespace::boolean;
   #endif

    static void fatalErrorHandler (j_common_ptr p)          { *((bool*) (p->client_data)) = true; }
    static void silentErrorCallback1 (j_common_ptr)         {}
    static void silentErrorCallback2 (j_common_ptr, int)    {}
    static void silentErrorCallback3 (j_common_ptr, char*)  {}

    static void setupSilentErrorHandler (struct jpeg_error_mgr& err)
    {
        zerostruct (err);

        err.error_exit      = fatalErrorHandler;
        err.emit_message    = silentErrorCallback2;
        err.output_message  = silentErrorCallback1;
        err.format_message  = silentErrorCallback3;
        err.reset_error_mgr = silentErrorCallback1;
    }

    //==============================================================================
   #if ! JUCE_USING_COREIMAGE_LOADER
    static void dummyCallback1 (j_decompress_ptr) {}

    static void jpegSkip (j_decompress_ptr decompStruct, long num)
    {
        decompStruct->src->next_input_byte += num;

        num = jmin (num, (long) decompStruct->src->bytes_in_buffer);
        decompStruct->src->bytes_in_buffer -= (size_t) num;
    }

    static boolean jpegFill (j_decompress_ptr)
    {
        return 0;
    }
   #endif

    //==============================================================================
    const int jpegBufferSize = 512;

    struct JuceJpegDest  : public jpeg_destination_mgr
    {
        OutputStream* output;
        char* buffer;
    };

    static void jpegWriteInit (j_compress_ptr) {}

    static void jpegWriteTerminate (j_compress_ptr cinfo)
    {
        JuceJpegDest* const dest = static_cast<JuceJpegDest*> (cinfo->dest);

        const size_t numToWrite = jpegBufferSize - dest->free_in_buffer;
        dest->output->write (dest->buffer, numToWrite);
    }

    static boolean jpegWriteFlush (j_compress_ptr cinfo)
    {
        JuceJpegDest* const dest = static_cast<JuceJpegDest*> (cinfo->dest);

        const int numToWrite = jpegBufferSize;

        dest->next_output_byte = reinterpret_cast<JOCTET*> (dest->buffer);
        dest->free_in_buffer = jpegBufferSize;

        return (boolean) dest->output->write (dest->buffer, (size_t) numToWrite);
    }
}

//==============================================================================
JPEGImageFormat::JPEGImageFormat()
    : quality (-1.0f)
{
}

JPEGImageFormat::~JPEGImageFormat() {}

void JPEGImageFormat::setQuality (const float newQuality)
{
    quality = newQuality;
}

String JPEGImageFormat::getFormatName()                   { return "JPEG"; }
bool JPEGImageFormat::usesFileExtension (const File& f)   { return f.hasFileExtension ("jpeg;jpg"); }

bool JPEGImageFormat::canUnderstand (InputStream& in)
{
    const int bytesNeeded = 24;
    uint8 header [bytesNeeded];

    if (in.read (header, bytesNeeded) == bytesNeeded
            && header[0] == 0xff
            && header[1] == 0xd8
            && header[2] == 0xff)
        return true;

   #if JUCE_USING_COREIMAGE_LOADER
    return header[20] == 'j'
        && header[21] == 'p'
        && header[22] == '2'
        && header[23] == ' ';
   #endif

    return false;
}

#if JUCE_USING_COREIMAGE_LOADER
 Image juce_loadWithCoreImage (InputStream& input);
#endif

Image JPEGImageFormat::decodeImage (InputStream& in)
{
#if JUCE_USING_COREIMAGE_LOADER
    return juce_loadWithCoreImage (in);
#else
    using namespace jpeglibNamespace;
    using namespace JPEGHelpers;

    MemoryOutputStream mb;
    mb << in;

    Image image;

    if (mb.getDataSize() > 16)
    {
        struct jpeg_decompress_struct jpegDecompStruct;

        struct jpeg_error_mgr jerr;
        setupSilentErrorHandler (jerr);
        jpegDecompStruct.err = &jerr;

        jpeg_create_decompress (&jpegDecompStruct);

        jpegDecompStruct.src = (jpeg_source_mgr*)(jpegDecompStruct.mem->alloc_small)
            ((j_common_ptr)(&jpegDecompStruct), JPOOL_PERMANENT, sizeof (jpeg_source_mgr));

        bool hasFailed = false;
        jpegDecompStruct.client_data = &hasFailed;

        jpegDecompStruct.src->init_source       = dummyCallback1;
        jpegDecompStruct.src->fill_input_buffer = jpegFill;
        jpegDecompStruct.src->skip_input_data   = jpegSkip;
        jpegDecompStruct.src->resync_to_restart = jpeg_resync_to_restart;
        jpegDecompStruct.src->term_source       = dummyCallback1;

        jpegDecompStruct.src->next_input_byte   = static_cast<const unsigned char*> (mb.getData());
        jpegDecompStruct.src->bytes_in_buffer   = mb.getDataSize();

        jpeg_read_header (&jpegDecompStruct, TRUE);

        if (! hasFailed)
        {
            jpeg_calc_output_dimensions (&jpegDecompStruct);

            if (! hasFailed)
            {
                const int width  = (int) jpegDecompStruct.output_width;
                const int height = (int) jpegDecompStruct.output_height;

                jpegDecompStruct.out_color_space = JCS_RGB;

                JSAMPARRAY buffer
                    = (*jpegDecompStruct.mem->alloc_sarray) ((j_common_ptr) &jpegDecompStruct,
                                                             JPOOL_IMAGE,
                                                             (JDIMENSION) width * 3, 1);

                if (jpeg_start_decompress (&jpegDecompStruct) && ! hasFailed)
                {
                    image = Image (Image::RGB, width, height, false);
                    image.getProperties()->set ("originalImageHadAlpha", false);
                    const bool hasAlphaChan = image.hasAlphaChannel(); // (the native image creator may not give back what we expect)

                    const Image::BitmapData destData (image, Image::BitmapData::writeOnly);

                    for (int y = 0; y < height; ++y)
                    {
                        jpeg_read_scanlines (&jpegDecompStruct, buffer, 1);

                        if (hasFailed)
                            break;

                        const uint8* src = *buffer;
                        uint8* dest = destData.getLinePointer (y);

                        if (hasAlphaChan)
                        {
                            for (int i = width; --i >= 0;)
                            {
                                ((PixelARGB*) dest)->setARGB (0xff, src[0], src[1], src[2]);
                                ((PixelARGB*) dest)->premultiply();
                                dest += destData.pixelStride;
                                src += 3;
                            }
                        }
                        else
                        {
                            for (int i = width; --i >= 0;)
                            {
                                ((PixelRGB*) dest)->setARGB (0xff, src[0], src[1], src[2]);
                                dest += destData.pixelStride;
                                src += 3;
                            }
                        }
                    }

                    if (! hasFailed)
                        jpeg_finish_decompress (&jpegDecompStruct);

                    in.setPosition (((char*) jpegDecompStruct.src->next_input_byte) - (char*) mb.getData());
                }
            }
        }

        jpeg_destroy_decompress (&jpegDecompStruct);
    }

    return image;
#endif
}

bool JPEGImageFormat::writeImageToStream (const Image& image, OutputStream& out)
{
    using namespace jpeglibNamespace;
    using namespace JPEGHelpers;

    jpeg_compress_struct jpegCompStruct;
    zerostruct (jpegCompStruct);
    jpeg_create_compress (&jpegCompStruct);

    struct jpeg_error_mgr jerr;
    setupSilentErrorHandler (jerr);
    jpegCompStruct.err = &jerr;

    JuceJpegDest dest;
    jpegCompStruct.dest = &dest;

    dest.output = &out;
    HeapBlock<char> tempBuffer (jpegBufferSize);
    dest.buffer = tempBuffer;
    dest.next_output_byte = (JOCTET*) dest.buffer;
    dest.free_in_buffer = jpegBufferSize;
    dest.init_destination = jpegWriteInit;
    dest.empty_output_buffer = jpegWriteFlush;
    dest.term_destination = jpegWriteTerminate;

    jpegCompStruct.image_width  = (JDIMENSION) image.getWidth();
    jpegCompStruct.image_height = (JDIMENSION) image.getHeight();
    jpegCompStruct.input_components = 3;
    jpegCompStruct.in_color_space = JCS_RGB;
    jpegCompStruct.write_JFIF_header = 1;

    jpegCompStruct.X_density = 72;
    jpegCompStruct.Y_density = 72;

    jpeg_set_defaults (&jpegCompStruct);

    jpegCompStruct.dct_method = JDCT_FLOAT;
    jpegCompStruct.optimize_coding = 1;

    if (quality < 0.0f)
        quality = 0.85f;

    jpeg_set_quality (&jpegCompStruct, jlimit (0, 100, roundToInt (quality * 100.0f)), TRUE);

    jpeg_start_compress (&jpegCompStruct, TRUE);

    const int strideBytes = (int) (jpegCompStruct.image_width * (unsigned int) jpegCompStruct.input_components);

    JSAMPARRAY buffer = (*jpegCompStruct.mem->alloc_sarray) ((j_common_ptr) &jpegCompStruct,
                                                             JPOOL_IMAGE, (JDIMENSION) strideBytes, 1);

    const Image::BitmapData srcData (image, Image::BitmapData::readOnly);

    while (jpegCompStruct.next_scanline < jpegCompStruct.image_height)
    {
        uint8* dst = *buffer;

        if (srcData.pixelFormat == Image::RGB)
        {
            const uint8* src = srcData.getLinePointer ((int) jpegCompStruct.next_scanline);

            for (int i = srcData.width; --i >= 0;)
            {
                *dst++ = ((const PixelRGB*) src)->getRed();
                *dst++ = ((const PixelRGB*) src)->getGreen();
                *dst++ = ((const PixelRGB*) src)->getBlue();
                src += srcData.pixelStride;
            }
        }
        else
        {
            for (int x = 0; x < srcData.width; ++x)
            {
                const Colour pixel (srcData.getPixelColour (x, (int) jpegCompStruct.next_scanline));
                *dst++ = pixel.getRed();
                *dst++ = pixel.getGreen();
                *dst++ = pixel.getBlue();
            }
        }

        jpeg_write_scanlines (&jpegCompStruct, buffer, 1);
    }

    jpeg_finish_compress (&jpegCompStruct);
    jpeg_destroy_compress (&jpegCompStruct);

    return true;
}

} // namespace juce