//
//  UIImage+Utility.m
//
//  Created by sho yakushiji on 2013/05/17.
//  Copyright (c) 2013年 CALACULU. All rights reserved.
//

#import "UIImage+Utility.h"

#import <Accelerate/Accelerate.h>

@implementation UIImage (Utility)

+ (UIImage*)decode:(UIImage*)image
{
    if(image==nil){  return nil; }
    
    UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
    {
        [image drawAtPoint:CGPointMake(0, 0)];
        image = UIGraphicsGetImageFromCurrentImageContext();
    }
    UIGraphicsEndImageContext();
    
    return image;
}

+ (UIImage*)fastImageWithData:(NSData *)data
{
    UIImage *image = [UIImage imageWithData:data];
    return [self decode:image];
}

+ (UIImage*)fastImageWithContentsOfFile:(NSString*)path
{
    UIImage *image = [[UIImage alloc] initWithContentsOfFile:path];
    return [self decode:image];
}

#pragma mark- Copy

- (UIImage*)deepCopy
{
    return [UIImage decode:self];
}

#pragma mark- GrayScale

- (UIImage*)grayScaleImage
{
    CGRect imageRect = CGRectMake(0, 0, self.size.width, self.size.height);
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    CGContextRef context = CGBitmapContextCreate(nil, self.size.width, self.size.height, 8, 0, colorSpace, kCGBitmapByteOrderDefault);
    
    CGContextDrawImage(context, imageRect, [self CGImage]);
    
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    UIImage *newImage = [UIImage imageWithCGImage:imageRef];
    
    CGColorSpaceRelease(colorSpace);
    CGContextRelease(context);
    CFRelease(imageRef);
    
    return newImage;
}

#pragma mark- Resizing

- (UIImage*)resize:(CGSize)size
{
    int W = size.width;
    int H = size.height;
    
    CGImageRef   imageRef   = self.CGImage;
    CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
    
    
    CGContextRef bitmap = CGBitmapContextCreate(NULL, W, H, 8, 4*W, colorSpaceInfo, kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little);
    
    if(self.imageOrientation == UIImageOrientationLeft || self.imageOrientation == UIImageOrientationRight){
        W = size.height;
        H = size.width;
    }
    
    if(self.imageOrientation == UIImageOrientationLeft || self.imageOrientation == UIImageOrientationLeftMirrored){
        CGContextRotateCTM (bitmap, M_PI/2);
        CGContextTranslateCTM (bitmap, 0, -H);
    }
    else if (self.imageOrientation == UIImageOrientationRight || self.imageOrientation == UIImageOrientationRightMirrored){
        CGContextRotateCTM (bitmap, -M_PI/2);
        CGContextTranslateCTM (bitmap, -W, 0);
    }
    else if (self.imageOrientation == UIImageOrientationUp || self.imageOrientation == UIImageOrientationUpMirrored){
        // Nothing
    }
    else if (self.imageOrientation == UIImageOrientationDown || self.imageOrientation == UIImageOrientationDownMirrored){
        CGContextTranslateCTM (bitmap, W, H);
        CGContextRotateCTM (bitmap, -M_PI);
    }
    
    CGContextDrawImage(bitmap, CGRectMake(0, 0, W, H), imageRef);
    CGImageRef ref = CGBitmapContextCreateImage(bitmap);
    UIImage* newImage = [UIImage imageWithCGImage:ref];
    
    CGContextRelease(bitmap);
    CGImageRelease(ref);
    return newImage;
}

- (UIImage*)aspectFit:(CGSize)size
{
    CGFloat ratio = MIN(size.width/self.size.width, size.height/self.size.height);
    return [self resize:CGSizeMake(self.size.width*ratio, self.size.height*ratio)];
}

- (UIImage*)aspectFill:(CGSize)size
{
    return [self aspectFill:size offset:0];
}

- (UIImage*)aspectFill:(CGSize)size offset:(CGFloat)offset
{
    int W  = size.width;
    int H  = size.height;
    int W0 = self.size.width;
    int H0 = self.size.height;
    
    CGImageRef   imageRef = self.CGImage;
    CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
    
    CGContextRef bitmap = CGBitmapContextCreate(NULL, W, H, 8, 4*W, colorSpaceInfo, kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little);
    
    if(self.imageOrientation == UIImageOrientationLeft || self.imageOrientation == UIImageOrientationRight){
        W  = size.height;
        H  = size.width;
        W0 = self.size.height;
        H0 = self.size.width;
    }
    
    double ratio = MAX(W/(double)W0, H/(double)H0);
    W0 = ratio * W0;
    H0 = ratio * H0;
    
    int dW = abs((W0-W)/2);
    int dH = abs((H0-H)/2);
    
    if(dW==0){ dH += offset; }
    if(dH==0){ dW += offset; }
    
    if(self.imageOrientation == UIImageOrientationLeft || self.imageOrientation == UIImageOrientationLeftMirrored){
        CGContextRotateCTM (bitmap, M_PI/2);
        CGContextTranslateCTM (bitmap, 0, -H);
    }
    else if (self.imageOrientation == UIImageOrientationRight || self.imageOrientation == UIImageOrientationRightMirrored){
        CGContextRotateCTM (bitmap, -M_PI/2);
        CGContextTranslateCTM (bitmap, -W, 0);
    }
    else if (self.imageOrientation == UIImageOrientationUp || self.imageOrientation == UIImageOrientationUpMirrored){
        // Nothing
    }
    else if (self.imageOrientation == UIImageOrientationDown || self.imageOrientation == UIImageOrientationDownMirrored){
        CGContextTranslateCTM (bitmap, W, H);
        CGContextRotateCTM (bitmap, -M_PI);
    }
    
    CGContextDrawImage(bitmap, CGRectMake(-dW, -dH, W0, H0), imageRef);
    CGImageRef ref = CGBitmapContextCreateImage(bitmap);
    UIImage* newImage = [UIImage imageWithCGImage:ref];
    
    CGContextRelease(bitmap);
    CGImageRelease(ref);
    
    return newImage;
}

#pragma mark- Clipping

- (UIImage*)crop:(CGRect)rect
{
    CGPoint origin = CGPointMake(-rect.origin.x, -rect.origin.y);
    
    UIImage *img = nil;
    
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, self.scale);
    [self drawAtPoint:origin];
    img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return img;
}

#pragma mark- Masking

- (UIImage*)maskedImage:(UIImage*)maskImage
{
    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskImage.CGImage),
                                        CGImageGetHeight(maskImage.CGImage),
                                        CGImageGetBitsPerComponent(maskImage.CGImage),
                                        CGImageGetBitsPerPixel(maskImage.CGImage),
                                        CGImageGetBytesPerRow(maskImage.CGImage),
                                        CGImageGetDataProvider(maskImage.CGImage), NULL, false);
    
    CGImageRef masked = CGImageCreateWithMask(self.CGImage, mask);
    
    UIImage *result = [UIImage imageWithCGImage:masked];
    
    CGImageRelease(mask);
    CGImageRelease(masked);
    
    return result;
}

#pragma mark- Blur

- (UIImage*)gaussBlur:(CGFloat)blurLevel
{
    blurLevel = MIN(1.0, MAX(0.0, blurLevel));
    
    int boxSize = (int)(blurLevel * 0.1 * MIN(self.size.width, self.size.height));
    boxSize = boxSize - (boxSize % 2) + 1;
    
    NSData *imageData = UIImageJPEGRepresentation([UIImage decode:self], 1);
    UIImage *tmpImage = [UIImage imageWithData:imageData];
    
    CGImageRef img = tmpImage.CGImage;
    vImage_Buffer inBuffer, outBuffer;
    vImage_Error error;
    void *pixelBuffer;
    
    //create vImage_Buffer with data from CGImageRef
    CGDataProviderRef inProvider = CGImageGetDataProvider(img);
    CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
    
    inBuffer.width = CGImageGetWidth(img);
    inBuffer.height = CGImageGetHeight(img);
    inBuffer.rowBytes = CGImageGetBytesPerRow(img);
    
    inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
    
    //create vImage_Buffer for output
    pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
    
    outBuffer.data = pixelBuffer;
    outBuffer.width = CGImageGetWidth(img);
    outBuffer.height = CGImageGetHeight(img);
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);
    
    NSInteger windowR = boxSize/2;
    CGFloat sig2 = windowR / 3.0;
    if(windowR>0){ sig2 = -1/(2*sig2*sig2); }
    
    int16_t *kernel = (int16_t*)malloc(boxSize*sizeof(int16_t));
    int32_t  sum = 0;
    for(NSInteger i=0; i<boxSize; ++i){
        kernel[i] = 255*exp(sig2*(i-windowR)*(i-windowR));
        sum += kernel[i];
    }
    
    // convolution
    error = vImageConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, kernel, boxSize, 1, sum, NULL, kvImageEdgeExtend)?:
    vImageConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, 0, 0, kernel, 1, boxSize, sum, NULL, kvImageEdgeExtend);
    outBuffer = inBuffer;
    
    free(kernel);
    
    if (error) {
        NSLog(@"error from convolution %ld", error);
    }
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate(outBuffer.data,
                                             outBuffer.width,
                                             outBuffer.height,
                                             8,
                                             outBuffer.rowBytes,
                                             colorSpace,
                                             kCGBitmapAlphaInfoMask & kCGImageAlphaNoneSkipLast);
    CGImageRef imageRef = CGBitmapContextCreateImage(ctx);
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
    
    //clean up
    CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);
    free(pixelBuffer);
    CFRelease(inBitmapData);
    CGImageRelease(imageRef);
    
    return returnImage;
}

@end
