#import <FastBlur/FastBlur.h>

#import <Accelerate/Accelerate.h>

static inline uint64_t get_colors (const uint8_t *p) {
    return p[0] + (p[1] << 16) + ((uint64_t)p[2] << 32);
}

void imageFastBlur(int imageWidth, int imageHeight, int imageStride, void * _Nonnull pixels)
{
    uint8_t *pix = (uint8_t *)pixels;
    const int w = imageWidth;
    const int h = imageHeight;
    const int stride = imageStride;
    const int radius = 3;
    const int r1 = radius + 1;
    const int div = radius * 2 + 1;
    
    if (radius > 15 || div >= w || div >= h)
    {
        return;
    }
    
    uint64_t *rgb = malloc(imageStride * imageHeight * sizeof(uint64_t));
    
    int x, y, i;
    
    int yw = 0;
    const int we = w - r1;
    for (y = 0; y < h; y++) {
        uint64_t cur = get_colors (&pix[yw]);
        uint64_t rgballsum = -radius * cur;
        uint64_t rgbsum = cur * ((r1 * (r1 + 1)) >> 1);
        
        for (i = 1; i <= radius; i++) {
            uint64_t cur = get_colors (&pix[yw + i * 4]);
            rgbsum += cur * (r1 - i);
            rgballsum += cur;
        }
        
        x = 0;
        
#define update(start, middle, end)                         \
rgb[y * w + x] = (rgbsum >> 4) & 0x00FF00FF00FF00FF; \
\
rgballsum += get_colors (&pix[yw + (start) * 4]) -   \
2 * get_colors (&pix[yw + (middle) * 4]) +  \
get_colors (&pix[yw + (end) * 4]);      \
rgbsum += rgballsum;                                 \
x++;                                                 \

        while (x < r1) {
            update (0, x, x + r1);
        }
        while (x < we) {
            update (x - r1, x, x + r1);
        }
        while (x < w) {
            update (x - r1, x, w - 1);
        }
#undef update
        
        yw += stride;
    }
    
    const int he = h - r1;
    for (x = 0; x < w; x++) {
        uint64_t rgballsum = -radius * rgb[x];
        uint64_t rgbsum = rgb[x] * ((r1 * (r1 + 1)) >> 1);
        for (i = 1; i <= radius; i++) {
            rgbsum += rgb[i * w + x] * (r1 - i);
            rgballsum += rgb[i * w + x];
        }
        
        y = 0;
        int yi = x * 4;
        
#define update(start, middle, end)         \
int64_t res = rgbsum >> 4;           \
pix[yi] = (uint8_t)res;                       \
pix[yi + 1] = (uint8_t)(res >> 16);             \
pix[yi + 2] = (uint8_t)(res >> 32);             \
\
rgballsum += rgb[x + (start) * w] -  \
2 * rgb[x + (middle) * w] + \
rgb[x + (end) * w];     \
rgbsum += rgballsum;                 \
y++;                                 \
yi += stride;
        
        while (y < r1) {
            update (0, y, y + r1);
        }
        while (y < he) {
            update (y - r1, y, y + r1);
        }
        while (y < h) {
            update (y - r1, y, h - 1);
        }
#undef update
    }
    
    free(rgb);
}

void telegramFastBlurMore(int imageWidth, int imageHeight, int imageStride, void * _Nonnull pixels)
{
    uint8_t *pix = (uint8_t *)pixels;
    const int w = imageWidth;
    const int h = imageHeight;
    const int stride = imageStride;
    const int radius = 7;
    const int r1 = radius + 1;
    const int div = radius * 2 + 1;
    
    if (radius > 15 || div >= w || div >= h)
    {
        return;
    }
    
    uint64_t *rgb = malloc(imageStride * imageHeight * sizeof(uint64_t));
    
    int x, y, i;
    
    int yw = 0;
    const int we = w - r1;
    for (y = 0; y < h; y++) {
        uint64_t cur = get_colors (&pix[yw]);
        uint64_t rgballsum = -radius * cur;
        uint64_t rgbsum = cur * ((r1 * (r1 + 1)) >> 1);
        
        for (i = 1; i <= radius; i++) {
            uint64_t cur = get_colors (&pix[yw + i * 4]);
            rgbsum += cur * (r1 - i);
            rgballsum += cur;
        }
        
        x = 0;
        
#define update(start, middle, end)                         \
rgb[y * w + x] = (rgbsum >> 6) & 0x00FF00FF00FF00FF; \
\
rgballsum += get_colors (&pix[yw + (start) * 4]) -   \
2 * get_colors (&pix[yw + (middle) * 4]) +  \
get_colors (&pix[yw + (end) * 4]);      \
rgbsum += rgballsum;                                 \
x++;                                                 \

        while (x < r1) {
            update (0, x, x + r1);
        }
        while (x < we) {
            update (x - r1, x, x + r1);
        }
        while (x < w) {
            update (x - r1, x, w - 1);
        }
#undef update
        
        yw += stride;
    }
    
    const int he = h - r1;
    for (x = 0; x < w; x++) {
        uint64_t rgballsum = -radius * rgb[x];
        uint64_t rgbsum = rgb[x] * ((r1 * (r1 + 1)) >> 1);
        for (i = 1; i <= radius; i++) {
            rgbsum += rgb[i * w + x] * (r1 - i);
            rgballsum += rgb[i * w + x];
        }
        
        y = 0;
        int yi = x * 4;
        
#define update(start, middle, end)         \
int64_t res = rgbsum >> 6;           \
pix[yi] = (uint8_t)res;                       \
pix[yi + 1] = (uint8_t)(res >> 16);             \
pix[yi + 2] = (uint8_t)(res >> 32);             \
\
rgballsum += rgb[x + (start) * w] -  \
2 * rgb[x + (middle) * w] + \
rgb[x + (end) * w];     \
rgbsum += rgballsum;                 \
y++;                                 \
yi += stride;
        
        while (y < r1) {
            update (0, y, y + r1);
        }
        while (y < he) {
            update (y - r1, y, y + r1);
        }
        while (y < h) {
            update (y - r1, y, h - 1);
        }
#undef update
    }
    
    free(rgb);
}

void stickerThumbnailAlphaBlur(int imageWidth, int imageHeight, int imageStride, void * _Nonnull pixels) {
    vImage_Buffer srcBuffer;
    srcBuffer.width = imageWidth;
    srcBuffer.height = imageHeight;
    srcBuffer.rowBytes = imageStride;
    srcBuffer.data = pixels;
    
    void *tempBytes = malloc(imageHeight * imageStride);
    
    {
        vImage_Buffer dstBuffer;
        dstBuffer.width = imageWidth;
        dstBuffer.height = imageHeight;
        dstBuffer.rowBytes = imageStride;
        dstBuffer.data = tempBytes;
        
        int boxSize = 2;
        boxSize = boxSize - (boxSize % 2) + 1;
        
        vImageBoxConvolve_ARGB8888(&srcBuffer, &dstBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
    }
    
    memcpy(pixels, tempBytes, imageHeight * imageStride);
    free(tempBytes);
}

static void modifyImage(void *pixels, unsigned int width, unsigned int height, unsigned int stride, int16_t * _Nonnull matrix)
{
    vImage_Buffer dstBuffer;
    dstBuffer.width = width;
    dstBuffer.height = height;
    dstBuffer.rowBytes = stride;
    dstBuffer.data = pixels;
    
    int32_t divisor = 256;
    vImageMatrixMultiply_ARGB8888(&dstBuffer, &dstBuffer, matrix, divisor, NULL, NULL, kvImageDoNotTile);
}

static void matrixMul(CGFloat * _Nonnull a, CGFloat * _Nonnull b, CGFloat *result)
{
    for (int i = 0; i != 4; ++i)
    {
        for (int j = 0; j != 4; ++j)
        {
            CGFloat sum = 0;
            for (int k = 0; k != 4; ++k)
            {
                sum += a[i + k * 4] * b[k + j * 4];
            }
            result[i + j * 4] = sum;
        }
    }
}

static int16_t *lightBrightenMatrix(int32_t * _Nullable outDivisor)
{
    static int16_t saturationMatrix[16];
    static const int32_t divisor = 256;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^
    {
        CGFloat s = 1.2f;
        CGFloat offset = 0.01f;
        CGFloat factor = 1.02f;
        CGFloat satMatrix[] = {
          0.0722f + 0.9278f * s,  0.0722f - 0.0722f * s,  0.0722f - 0.0722f * s,  0,
          0.7152f - 0.7152f * s,  0.7152f + 0.2848f * s,  0.7152f - 0.7152f * s,  0,
          0.2126f - 0.2126f * s,  0.2126f - 0.2126f * s,  0.2126f + 0.7873f * s,  0,
          0.0f,                    0.0f,                    0.0f,  1,
        };
        CGFloat contrastMatrix[] = {
          factor, 0.0f, 0.0f, 0.0f,
          0.0f, factor, 0.0f, 0.0f,
          0.0f, 0.0f, factor, 0.0f,
          offset, offset, offset, 1.0f
        };
        CGFloat colorMatrix[16];
        matrixMul(satMatrix, contrastMatrix, colorMatrix);

        NSUInteger matrixSize = sizeof(colorMatrix) / sizeof(colorMatrix[0]);
        for (NSUInteger i = 0; i < matrixSize; ++i) {
            saturationMatrix[i] = (int16_t)round(colorMatrix[i] * divisor);
        }
    });
    
    if (outDivisor != NULL)
        *outDivisor = divisor;
    
    return saturationMatrix;
}

void telegramBrightenImage(int imageWidth, int imageHeight, int imageStride, void * _Nonnull pixels)
{
    modifyImage(pixels, imageWidth, imageHeight, imageStride, lightBrightenMatrix(NULL));
}