#ifndef __C_BLP_IMAGE_LOADER_H_INCLUDED__
#define __C_BLP_IMAGE_LOADER_H_INCLUDED__

/**
 * Copyright (C) <2014>
 * Ovan/Magun contact on irrlicht-fr.org or ovan@sleek-think.ovh
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
**/

#include "IrrCompileConfig.h"
#define _IRR_COMPILE_WITH_BLP_LOADER_

// force plugin compilation
// guard efined if loader included to the engine
#ifdef _IRR_COMPILE_WITH_BLP_LOADER_

#include <IImageLoader.h>

namespace irr
{
    namespace video
    {
        struct sharedheader;
        class IVideoDriver;
        class CImageLoaderBLP : public IImageLoader
        {
            protected:
                enum Compression : int
                {
                    JPG = 0,
                    BLP = 1,
                    RAW = 2,
                    DXT = 3
                };
            public:
                CImageLoaderBLP(IVideoDriver*);
                virtual ~CImageLoaderBLP();

                virtual bool isALoadableFileExtension(const io::path& filename) const;
                virtual bool isALoadableFileFormat(io::IReadFile* file) const;
                virtual IImage* loadImage(io::IReadFile* file) const;
            protected:
                IImage* decompressBLP(const sharedheader&, char *, size_t) const;
                IImage* decompressDXT(const sharedheader&, char *, size_t) const;
                IImage* decompressRaw(const sharedheader&, char *, size_t) const;
                IImage* decompressJpg(const sharedheader&, char *, size_t) const;
            private:
                IVideoDriver *driver;
        };

        IImageLoader* createImageLoaderBLP();
    }
}

#endif
#endif 

#include "CImageLoaderBLP.h"

#ifdef _IRR_COMPILE_WITH_BLP_LOADER_

#include <IVideoDriver.h>
#include <IReadFile.h>
#include <IImage.h>
#include <irrString.h>
#include <iostream>
#include "jpeglib.h"

namespace irr
{
    namespace video
    {
        struct sharedheader
        {
            u32 compression;
            u32 flags;
            u32 width;
            u32 height;
            u32 alpha_depth;
            u32 mipmap_offsets[16];
            u32 mipmap_lengths[16];
            u32 palette[265];
        };

        struct blpheader
        {
            u32 compression;
            u32 flags;
            u32 width;
            u32 height;
            u32 alpha_depth;
            u32 pictureSubType;
            u32 mipmap_offsets[16];
            u32 mipmap_lengths[16];
        };

        struct blp2header
        {
            u32   type;               // 0 = JPG, 1 = BLP / DXTC / Uncompressed
            u8    compression;        // 1 = BLP, 2 = DXTC, 3 = Uncompressed
            u8    alpha_depth;        // 0, 1, 4, or 8
            u8    alpha_type;         // 0, 1, 7, or 8
            u8    has_mips;           // 0 = no mips, 1 = has mips
            u32   width;              // Image width in pixels, usually a power of 2
            u32   height;             // Image height in pixels, usually a power of 2
            u32   mipmap_offsets[16]; // The file offsets of each mipmap, 0 for unused
            u32   mipmap_lengths[16]; // The length of each mipmap data block
        };

        CImageLoaderBLP::CImageLoaderBLP(irr::video::IVideoDriver *d) : driver(d)
        {
            #ifdef _DEBUG
            setDebugName("CImageLoaderBLP");
            #endif
        }

        //! destructor
        CImageLoaderBLP::~CImageLoaderBLP()
        {
        }

        bool CImageLoaderBLP::isALoadableFileExtension(const io::path& filename) const
        {
            return core::hasFileExtension(filename, "blp");
        }

        bool CImageLoaderBLP::isALoadableFileFormat(io::IReadFile* file) const
        {
            if(!file)
                return false;

            char buf[4];
            file->read(buf, 4);

            return buf[0] == 'B' && buf[1] == 'L' && buf[2] == 'P' &&
                   (buf[3] == '2' || buf[3] == '1' || buf[3] == '0');
        }

        IImage* CImageLoaderBLP::loadImage(io::IReadFile* file) const
        {
            if(!file)
                return 0;

            char blpid[4];
            file->read(blpid, 4);

            if(blpid[0] != 'B' || blpid[1] != 'L' || blpid[2] != 'P' ||
               !(blpid[3] == '2' || blpid[3] == '1' || blpid[3] == '0'))
               return 0;

            sharedheader shd;

            if(blpid[3] < '2')
            {
                std::cout << "war3 revision" << std::endl;

                blpheader header;
                file->read(&header, sizeof(blpheader));

                shd.compression = header.compression;
                shd.flags = header.flags;
                shd.width = header.width;
                shd.height = header.height;
                shd.alpha_depth = header.alpha_depth;

                for(int i = 0; i<16; ++i)
                {
                    shd.mipmap_offsets[i] = header.mipmap_offsets[i];
                    shd.mipmap_lengths[i] = header.mipmap_lengths[i];
                }
            }
            else
            {
                std::cout << "wow revision" << std::endl;

                blp2header header;
                file->read(&header, sizeof(blp2header));

                shd.flags = header.alpha_type;
                shd.width = header.width;
                shd.height = header.height;
                shd.alpha_depth = header.alpha_depth;

                for(int i = 0; i<16; ++i)
                {
                    shd.mipmap_offsets[i] = header.mipmap_offsets[i];
                    shd.mipmap_lengths[i] = header.mipmap_lengths[i];
                }

                if(header.type == 0)
                    shd.compression = JPG;
                else
                {
                    switch(header.compression)
                    {
                        case 1:  shd.compression = BLP; break;
                        case 2:  shd.compression = DXT; break;
                        default: shd.compression = RAW; break;
                    }
                    shd.flags = header.alpha_depth;
                }
            }

            std::cout << "compression: " << std::to_string(shd.compression) << std::endl;
            // only the first mipmap is loader, other can be generated by the engine

            switch(shd.compression)
            {
                case JPG:
                {
                    u32 jpegHeaderSize = 0;
                    file->read(&jpegHeaderSize, 4);
                    char *data = new char[shd.mipmap_lengths[0] + jpegHeaderSize];
                    file->read(data, jpegHeaderSize);
                    file->seek(shd.mipmap_offsets[0]);
                    file->read(data+jpegHeaderSize, shd.mipmap_lengths[0]);
                    return decompressJpg(shd, data, shd.mipmap_lengths[0] + jpegHeaderSize);
                }
                break;
                case BLP:
                {
                    file->read(shd.palette, 256*sizeof(u32));
                    for(int i = 0; i<256; ++i)
                    {
                        // from rgba
                        SColor c = shd.palette[i];
                        shd.palette[i] = SColor(
                            255-c.getRed(),
                            c.getGreen(),
                            c.getBlue(),
                            c.getAlpha()
                        ).color;
                    }
                    file->seek(shd.mipmap_offsets[0]);
                    char *data = new char[shd.mipmap_lengths[0]];
                    file->read(data, shd.mipmap_lengths[0]);
                    return decompressBLP(shd, data, shd.mipmap_lengths[0]);
                }
                break;
                case DXT:
                {
                    file->seek(shd.mipmap_offsets[0]);
                    char *data = new char[shd.mipmap_lengths[0]];
                    file->read(data, shd.mipmap_lengths[0]);
                    return decompressDXT(shd, data, shd.mipmap_lengths[0]);
                }
                break;
                default:
                {
                    file->seek(shd.mipmap_offsets[0]);
                    char *data = new char[shd.mipmap_lengths[0]];
                    file->read(data, shd.mipmap_lengths[0]);
                    return decompressRaw(shd, data, shd.mipmap_lengths[0]);
                }
                break;
            }

            return 0;
        }

        IImage* CImageLoaderBLP::decompressBLP(const sharedheader &header, char *data, size_t size) const
        {
            IImage *tmp = driver->createImage(
                ECF_A8R8G8B8,
                core::dimension2du(header.width, header.height)
            );

            for(int height = 0; height < header.height; ++height)
            {
                for(int width = 0; width < header.width; ++width)
                {
                    unsigned char index = (unsigned char)data[width + header.width*height];
                    tmp->setPixel(width, height, SColor(header.palette[index]));
                }
            }

            if(header.alpha_depth == 3 || header.alpha_depth == 4)
            {
                char *alpha = data + header.width*header.height;
                for(int height = 0; height < header.height; ++height)
                {
                    for(int width = 0; width < header.width; ++width)
                    {
                        SColor c(tmp->getPixel(width, height));
                        c.setAlpha(alpha[width + header.width*height]);
                        tmp->setPixel(width, height, c);
                    }
                }
            }

            delete [] data;
            return tmp;
        }
        IImage* CImageLoaderBLP::decompressDXT(const sharedheader &header, char *data, size_t size) const
        {
            ECOLOR_FORMAT dxt;

            // untested section (no file found)
            // the doc tell that the header.palette is used to compute DXTC
            // but I suppose that irrlicht DXTC does not require it

            if(header.flags == 0)
                dxt = ECF_DXT1;
            if(header.flags == 1)
                dxt = ECF_DXT3;
            if(header.flags == 7)
                dxt = ECF_DXT5;

            return driver->createImageFromData(
                dxt,
                core::dimension2du(header.width, header.height),
                data, true, true
            );
        }
        IImage* CImageLoaderBLP::decompressRaw(const sharedheader &header, char *data, size_t size) const
        {
            ECOLOR_FORMAT dxt;

            if(header.alpha_depth == 0)
                 dxt = ECF_R8G8B8;
            else dxt = ECF_A8R8G8B8;

            // untested section (no file found)

            IImage *tmp = driver->createImageFromData(
                ECF_A8R8G8B8,
                core::dimension2du(header.width, header.height),
                data, true, true
            );

            return tmp;
        }
        IImage* CImageLoaderBLP::decompressJpg(const sharedheader &header, char *buffer, size_t size) const
        {
            struct jpeg_error_mgr jerr;
            struct jpeg_decompress_struct cinfo;
            cinfo.err = jpeg_std_error(&jerr);
            jpeg_create_decompress(&cinfo);

            jpeg_mem_src(&cinfo, (unsigned char*)buffer, size);

            if(jpeg_read_header(&cinfo, TRUE) != JPEG_HEADER_OK ||
              !jpeg_start_decompress(&cinfo))
            {
                jpeg_finish_decompress(&cinfo);
                jpeg_destroy_decompress(&cinfo);
                return 0;
            }

            IImage *tmp = driver->createImage(
                ECF_A8R8G8B8,
                core::dimension2du(cinfo.image_width, cinfo.image_height)
            );

            const JDIMENSION requiredScanlines = cinfo.output_height;
            const JDIMENSION scanlineSize = cinfo.output_width * cinfo.output_components;

            JSAMPARRAY scanlines = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, scanlineSize, requiredScanlines);

            while(cinfo.output_scanline < cinfo.output_height)
            {
                const JDIMENSION currentScanline = cinfo.output_scanline;
                const JDIMENSION dimension = jpeg_read_scanlines(&cinfo, scanlines, requiredScanlines);

                for(int height = 0; height < dimension; ++height)
                {
                    int width = 0;
                    for(int component = 0; component < scanlineSize; component += cinfo.output_components)
                    {
                        u32 argb = ((u32)scanlines[height][component]) |
                                   ((u32)scanlines[height][component + 1] << 8) |
                                   ((u32)scanlines[height][component + 2] << 16);

                        if(cinfo.output_components == 4)
                            argb |= ((u32)(scanlines[height][component + 3]) << 24);

                        tmp->setPixel(width, height + currentScanline, argb);
                        ++width;
                    }
                }
            }

            jpeg_finish_decompress(&cinfo);
            jpeg_destroy_decompress(&cinfo);
            return tmp;
        }
    }
}

#endif

 driver->addExternalImageLoader(new irr::video::CImageLoaderBLP(driver));
driver->getTexture("*.blp");