#include "../io.h"
#include "logger.h"
#include <csetjmp>
#include <cstring>
#include <filesystem>
extern "C"
{
#include "libs/jpeg/jpeglib.h"
}

#define INVERT_ENDIAN_16(x) ((x >> 8) | (x << 8))

namespace satdump
{
    namespace image
    {
        struct jpeg_error_struct_l
        {
            struct jpeg_error_mgr pub;
            jmp_buf setjmp_buffer;
        };

        static void libjpeg_error_func_l(j_common_ptr cinfo) { longjmp(((jpeg_error_struct_l *)cinfo->err)->setjmp_buffer, 1); }

        void load_jpeg(Image &img, std::string file)
        {
            if (!std::filesystem::exists(file))
                return;

            FILE *fp = fopen(file.c_str(), "rb");
            if (!fp)
                abort();

            // Huge thanks to https://gist.github.com/PhirePhly/3080633
            unsigned char *jpeg_decomp[1] = {nullptr};
            jpeg_error_struct_l jerr;
            jpeg_decompress_struct cinfo;

            // Init
            cinfo.err = jpeg_std_error(&jerr.pub);
            jerr.pub.error_exit = libjpeg_error_func_l;

            if (setjmp(jerr.setjmp_buffer))
            {
                // Free memory
                delete[] jpeg_decomp[0];
                fclose(fp);
                return;
            }

            jpeg_create_decompress(&cinfo);

            // Parse and start decompressing
            jpeg_stdio_src(&cinfo, fp);
            jpeg_read_header(&cinfo, FALSE);
            jpeg_start_decompress(&cinfo);

            // Init output buffer
            jpeg_decomp[0] = new unsigned char[cinfo.image_width * cinfo.num_components];

            // Init SatDump image
            img.init(8, cinfo.image_width, cinfo.image_height, cinfo.num_components);

            // Decompress
            while (cinfo.output_scanline < cinfo.output_height)
            {
                jpeg_read_scanlines(&cinfo, jpeg_decomp, 1);
                for (int i = 0; i < (int)cinfo.image_width; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        img.set(c, ((cinfo.output_scanline - 1) * cinfo.image_width) + i, jpeg_decomp[0][i * cinfo.num_components + c]);
            }

            // Cleanup
            jpeg_finish_decompress(&cinfo);
            jpeg_destroy_decompress(&cinfo);

            // Free memory
            delete[] jpeg_decomp[0];
            fclose(fp);
        }

        void load_jpeg(Image &img, uint8_t *buffer, int size)
        {
            // Huge thanks to https://gist.github.com/PhirePhly/3080633
            unsigned char *jpeg_decomp[1] = {nullptr};
            jpeg_error_struct_l jerr;
            jpeg_decompress_struct cinfo;

            // Init
            cinfo.err = jpeg_std_error(&jerr.pub);
            jerr.pub.error_exit = libjpeg_error_func_l;

            if (setjmp(jerr.setjmp_buffer))
            {
                // Free memory
                delete[] jpeg_decomp[0];
                return;
            }

            jpeg_create_decompress(&cinfo);

            // Parse and start decompressing
            jpeg_mem__src(&cinfo, buffer, size);
            jpeg_read_header(&cinfo, FALSE);
            jpeg_start_decompress(&cinfo);

            // Init output buffer
            jpeg_decomp[0] = new unsigned char[cinfo.image_width * cinfo.num_components];

            // Init SatDump image
            img.init(8, cinfo.image_width, cinfo.image_height, cinfo.num_components);

            // Decompress
            while (cinfo.output_scanline < cinfo.output_height)
            {
                jpeg_read_scanlines(&cinfo, jpeg_decomp, 1);
                for (int i = 0; i < (int)cinfo.image_width; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        img.set(c, ((cinfo.output_scanline - 1) * cinfo.image_width) + i, jpeg_decomp[0][i * cinfo.num_components + c]);
            }

            // Cleanup
            jpeg_finish_decompress(&cinfo);
            jpeg_destroy_decompress(&cinfo);

            // Free memory
            delete[] jpeg_decomp[0];
        }

        void save_jpeg(Image &img, std::string file)
        {
            auto d_depth = img.depth();
            auto d_channels = img.channels();
            auto d_height = img.height();
            auto d_width = img.width();

            if (img.size() == 0 || d_height == 0) // Make sure we aren't just gonna crash
            {
                logger->trace("Tried to save empty JPEG!");
                return;
            }

            FILE *fp = fopen(file.c_str(), "wb");
            if (!fp)
                abort();

            unsigned char *jpeg_decomp = NULL;
            jpeg_error_struct_l jerr;
            jpeg_compress_struct cinfo;

            // Init
            cinfo.err = jpeg_std_error(&jerr.pub);
            jerr.pub.error_exit = libjpeg_error_func_l;

            if (setjmp(jerr.setjmp_buffer))
            {
                // Free memory
                delete[] jpeg_decomp;
                fclose(fp);
                return;
            }

            jpeg_create_compress(&cinfo);

            // Parse and start decompressing
            jpeg_stdio_dest(&cinfo, fp);
            cinfo.image_width = d_width;
            cinfo.image_height = d_height;
            int jpeg_channels = d_channels == 4 ? 3 : d_channels;
            cinfo.input_components = jpeg_channels;
            cinfo.in_color_space = jpeg_channels == 3 ? JCS_RGB : JCS_GRAYSCALE;
            jpeg_set_defaults(&cinfo);
            jpeg_set_quality(&cinfo, 90, true);
            jpeg_start_compress(&cinfo, true);

            // Init output buffer
            jpeg_decomp = new unsigned char[cinfo.image_width * cinfo.image_height * cinfo.num_components];

            // Copy over
            if (d_depth == 8)
            {
                for (int i = 0; i < (int)d_width * (int)d_height; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        jpeg_decomp[i * cinfo.num_components + c] = img.get(c, i);
            }
            else if (d_depth == 16)
            {
                for (int i = 0; i < (int)d_width * (int)d_height; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        jpeg_decomp[i * cinfo.num_components + c] = img.get(c, i) >> 8; // Scale down to 8 if required
            }

            // Apply transparency, if applicable
            if (d_channels == 4)
                for (int i = 0; i < (int)d_width * (int)d_height; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        jpeg_decomp[i * cinfo.num_components + c] *= (float)img.get(3, i) / img.maxval();

            // Compress
            while (cinfo.next_scanline < cinfo.image_height)
            {
                unsigned char *buffer_array[1];
                buffer_array[0] = jpeg_decomp + (cinfo.next_scanline) * cinfo.image_width * cinfo.num_components;
                jpeg_write_scanlines(&cinfo, buffer_array, 1);
            }

            jpeg_finish_compress(&cinfo);
            jpeg_destroy_compress(&cinfo);

            // Free memory
            fclose(fp);
            delete[] jpeg_decomp;
        }

        // Declaration is in jpeg_utils.h
        namespace
        {
            std::vector<uint8_t> j_buffer;
#define BLOCK_SIZE 16384

            void jpeg_init_destination(j_compress_ptr cinfo)
            {
                j_buffer.resize(BLOCK_SIZE);
                cinfo->dest->next_output_byte = &j_buffer[0];
                cinfo->dest->free_in_buffer = j_buffer.size();
            }

            jboolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
            {
                size_t oldsize = j_buffer.size();
                j_buffer.resize(oldsize + BLOCK_SIZE);
                cinfo->dest->next_output_byte = &j_buffer[oldsize];
                cinfo->dest->free_in_buffer = j_buffer.size() - oldsize;
                return true;
            }

            void jpeg_term_destination(j_compress_ptr cinfo) { j_buffer.resize(j_buffer.size() - cinfo->dest->free_in_buffer); }

            std::mutex jpeg_mem_mtex;
        } // namespace

        std::vector<uint8_t> save_jpeg_mem(Image &img)
        {
            auto d_depth = img.depth();
            auto d_channels = img.channels();
            auto d_height = img.height();
            auto d_width = img.width();

            jpeg_mem_mtex.lock();
            if (img.size() == 0 || d_height == 0) // Make sure we aren't just gonna crash
            {
                logger->trace("Tried to save empty JPEG!");
                jpeg_mem_mtex.unlock();
                return std::vector<uint8_t>();
            }

            unsigned char *jpeg_decomp = NULL;
            jpeg_error_struct_l jerr;
            jpeg_compress_struct cinfo;

            // Init
            cinfo.err = jpeg_std_error(&jerr.pub);
            jerr.pub.error_exit = libjpeg_error_func_l;

            if (setjmp(jerr.setjmp_buffer))
            {
                // Free memory
                delete[] jpeg_decomp;
                jpeg_mem_mtex.unlock();
                return std::vector<uint8_t>();
            }

            jpeg_create_compress(&cinfo);

            // Parse and start decompressing
            cinfo.dest = (struct jpeg_destination_mgr *)malloc(sizeof(struct jpeg_destination_mgr));
            cinfo.dest->init_destination = &jpeg_init_destination;
            cinfo.dest->empty_output_buffer = &jpeg_empty_output_buffer;
            cinfo.dest->term_destination = &jpeg_term_destination;

            cinfo.image_width = d_width;
            cinfo.image_height = d_height;
            int jpeg_channels = d_channels == 4 ? 3 : d_channels;
            cinfo.input_components = jpeg_channels;
            cinfo.in_color_space = jpeg_channels == 3 ? JCS_RGB : JCS_GRAYSCALE;
            jpeg_set_defaults(&cinfo);
            jpeg_set_quality(&cinfo, 90, true);
            jpeg_start_compress(&cinfo, true);

            // Init output buffer
            jpeg_decomp = new unsigned char[cinfo.image_width * cinfo.image_height * cinfo.num_components];

            // Copy over
            if (d_depth == 8)
            {
                for (int i = 0; i < (int)d_width * (int)d_height; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        jpeg_decomp[i * cinfo.num_components + c] = img.get(c, i);
            }
            else if (d_depth == 16)
            {
                for (int i = 0; i < (int)d_width * (int)d_height; i++)
                    for (int c = 0; c < cinfo.num_components; c++)
                        jpeg_decomp[i * cinfo.num_components + c] = img.get(c, i) >> 8; // Scale down to 8 if required
            }

            // Compress
            while (cinfo.next_scanline < cinfo.image_height)
            {
                unsigned char *buffer_array[1];
                buffer_array[0] = jpeg_decomp + (cinfo.next_scanline) * cinfo.image_width * cinfo.num_components;
                jpeg_write_scanlines(&cinfo, buffer_array, 1);
            }

            jpeg_finish_compress(&cinfo);
            free(cinfo.dest);
            jpeg_destroy_compress(&cinfo);

            // Free memory
            delete[] jpeg_decomp;
            jpeg_mem_mtex.unlock();
            return j_buffer;
        }
    } // namespace image
} // namespace satdump