//
//  Copyright © 2015年 Anson. All rights reserved.
//

#import "UIImage+LeChange.h"

CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};


@implementation UIImage (LeChange)

- (CGFloat)width {
    return self.size.width;
}

- (CGFloat)height {
    return self.size.height;
}

- (UIImage *)applyBlurWithRadius:(CGFloat)blurRadius
                       tintColor:(UIColor *)tintColor
           saturationDeltaFactor:(CGFloat)saturationDeltaFactor
                       maskImage:(UIImage *)maskImage
{
    // Check pre-conditions.
    if (self.size.width < 1 || self.size.height < 1) {
        NSLog (@"*** error: invalid size: (%.2f x %.2f). Both dimensions must be >= 1: %@", self.size.width, self.size.height, self);
        return nil;
    }
    if (!self.CGImage) {
        NSLog (@"*** error: image must be backed by a CGImage: %@", self);
        return nil;
    }
    if (maskImage && !maskImage.CGImage) {
        NSLog (@"*** error: maskImage must be backed by a CGImage: %@", maskImage);
        return nil;
    }

    CGRect imageRect = { CGPointZero, self.size };
    UIImage *effectImage = self;

    BOOL hasBlur = blurRadius > __FLT_EPSILON__;
    BOOL hasSaturationChange = fabs(saturationDeltaFactor - 1.) > __FLT_EPSILON__;
    if (hasBlur || hasSaturationChange) {
        UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
        CGContextRef effectInContext = UIGraphicsGetCurrentContext();
        CGContextScaleCTM(effectInContext, 1.0, -1.0);
        CGContextTranslateCTM(effectInContext, 0, -self.size.height);
        CGContextDrawImage(effectInContext, imageRect, self.CGImage);

        vImage_Buffer effectInBuffer;
        effectInBuffer.data     = CGBitmapContextGetData(effectInContext);
        effectInBuffer.width    = CGBitmapContextGetWidth(effectInContext);
        effectInBuffer.height   = CGBitmapContextGetHeight(effectInContext);
        effectInBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectInContext);

        UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
        CGContextRef effectOutContext = UIGraphicsGetCurrentContext();
        vImage_Buffer effectOutBuffer;
        effectOutBuffer.data     = CGBitmapContextGetData(effectOutContext);
        effectOutBuffer.width    = CGBitmapContextGetWidth(effectOutContext);
        effectOutBuffer.height   = CGBitmapContextGetHeight(effectOutContext);
        effectOutBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectOutContext);

        if (hasBlur) {
            // A description of how to compute the box kernel width from the Gaussian
            // radius (aka standard deviation) appears in the SVG spec:
            // http://www.w3.org/TR/SVG/filters.html#feGaussianBlurElement
            //
            // For larger values of 's' (s >= 2.0), an approximation can be used: Three
            // successive box-blurs build a piece-wise quadratic convolution kernel, which
            // approximates the Gaussian kernel to within roughly 3%.
            //
            // let d = floor(s * 3*sqrt(2*pi)/4 + 0.5)
            //
            // ... if d is odd, use three box-blurs of size 'd', centered on the output pixel.
            //
            CGFloat inputRadius = blurRadius * [[UIScreen mainScreen] scale];
            NSUInteger radius = floor(inputRadius * 3. * sqrt(2 * M_PI) / 4 + 0.5);
            if (radius % 2 != 1) {
                radius += 1; // force radius to be odd so that the three box-blur methodology works.
            }
            vImageBoxConvolve_ARGB8888(&effectInBuffer, &effectOutBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
            vImageBoxConvolve_ARGB8888(&effectOutBuffer, &effectInBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
            vImageBoxConvolve_ARGB8888(&effectInBuffer, &effectOutBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
        }
        BOOL effectImageBuffersAreSwapped = NO;
        if (hasSaturationChange) {
            CGFloat s = saturationDeltaFactor;
            CGFloat floatingPointSaturationMatrix[] = {
                0.0722 + 0.9278 * s,  0.0722 - 0.0722 * s,  0.0722 - 0.0722 * s,  0,
                0.7152 - 0.7152 * s,  0.7152 + 0.2848 * s,  0.7152 - 0.7152 * s,  0,
                0.2126 - 0.2126 * s,  0.2126 - 0.2126 * s,  0.2126 + 0.7873 * s,  0,
                0,                    0,                    0,  1,
            };
            const int32_t divisor = 256;
            NSUInteger matrixSize = sizeof(floatingPointSaturationMatrix)/sizeof(floatingPointSaturationMatrix[0]);
            int16_t saturationMatrix[matrixSize];
            for (NSUInteger i = 0; i < matrixSize; ++i) {
                saturationMatrix[i] = (int16_t)roundf(floatingPointSaturationMatrix[i] * divisor);
            }
            if (hasBlur) {
                vImageMatrixMultiply_ARGB8888(&effectOutBuffer, &effectInBuffer, saturationMatrix, divisor, NULL, NULL, kvImageNoFlags);
                effectImageBuffersAreSwapped = YES;
            }
            else {
                vImageMatrixMultiply_ARGB8888(&effectInBuffer, &effectOutBuffer, saturationMatrix, divisor, NULL, NULL, kvImageNoFlags);
            }
        }
        if (!effectImageBuffersAreSwapped)
            effectImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        if (effectImageBuffersAreSwapped)
            effectImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }

    // Set up output context.
    UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
    CGContextRef outputContext = UIGraphicsGetCurrentContext();
    CGContextScaleCTM(outputContext, 1.0, -1.0);
    CGContextTranslateCTM(outputContext, 0, -self.size.height);

    // Draw base image.
    CGContextDrawImage(outputContext, imageRect, self.CGImage);

    // Draw effect image.
    if (hasBlur) {
        CGContextSaveGState(outputContext);
        if (maskImage) {
            CGContextClipToMask(outputContext, imageRect, maskImage.CGImage);
        }
        CGContextDrawImage(outputContext, imageRect, effectImage.CGImage);
        CGContextRestoreGState(outputContext);
    }

    // Add in color tint.
    if (tintColor) {
        CGContextSaveGState(outputContext);
        CGContextSetFillColorWithColor(outputContext, tintColor.CGColor);
        CGContextFillRect(outputContext, imageRect);
        CGContextRestoreGState(outputContext);
    }

    // Output image is ready.
    UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return outputImage;
}


- (UIImage *)lc_imageWithBlurLevel:(CGFloat)blur
{
    UIColor *tintColor = [[UIColor blackColor] colorWithAlphaComponent:0.2];
    return [self applyBlurWithRadius:blur tintColor:tintColor saturationDeltaFactor:1.8 maskImage:nil];
}

- (BOOL)lc_writeToFileAtPath:(NSString*)aPath
{
    if ((self == nil) || (aPath == nil) || ([aPath isEqualToString:@""]))
        return NO;

    @try
    {
        NSData *imageData = nil;
        NSString *ext = [aPath pathExtension];
        if ([ext isEqualToString:@"png"])
        {
            imageData = UIImagePNGRepresentation(self);
        }
        else
        {
            // the rest, we write to jpeg
            // 0. best, 1. lost. about compress.
            imageData = UIImageJPEGRepresentation(self, 1);
        }

        if ((imageData == nil) || ([imageData length] <= 0))
            return NO;

        [imageData writeToFile:aPath atomically:YES];
        return YES;
    }
    @catch (NSException *e)
    {
        NSLog(@"create thumbnail exception.");
    }

    return NO;
}

+ (UIImage *)lc_imageWithScreenContents
{
    UIGraphicsBeginImageContextWithOptions([UIScreen mainScreen].bounds.size, YES, 1.0);
    [[UIApplication sharedApplication].keyWindow.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *uiImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return uiImage;
}

+ (UIImage*)lc_createImageWithColor: (UIColor*) color
{
    CGRect rect=CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return theImage;
}

-(UIImage *)lc_imageAtRect:(CGRect)rect
{
    CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect);
    UIImage* subImage = [UIImage imageWithCGImage: imageRef];
    CGImageRelease(imageRef);

    return subImage;

}

- (UIImage *)lc_imageByScalingProportionallyToMinimumSize:(CGSize)targetSize
{

    UIImage *sourceImage = self;
    UIImage *newImage = nil;

    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;

    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;

    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;

    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    if (CGSizeEqualToSize(imageSize, targetSize) == NO) {

        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor > heightFactor)
            scaleFactor = widthFactor;
        else
            scaleFactor = heightFactor;

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // center the image

        if (widthFactor > heightFactor) {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        } else if (widthFactor < heightFactor) {
            thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
        }
    }


    // this is actually the interesting part:

    UIGraphicsBeginImageContext(targetSize);

    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if(newImage == nil) NSLog(@"could not scale image");


    return newImage ;
}

- (UIImage *)lc_imageByScalingProportionallyToSize:(CGSize)targetSize
{

    UIImage *sourceImage = self;
    UIImage *newImage = nil;

    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;

    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;

    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;

    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    if (CGSizeEqualToSize(imageSize, targetSize) == NO) {

        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor < heightFactor)
            scaleFactor = widthFactor;
        else
            scaleFactor = heightFactor;

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // center the image

        if (widthFactor < heightFactor) {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        } else if (widthFactor > heightFactor) {
            thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
        }
    }


    // this is actually the interesting part:

    UIGraphicsBeginImageContext(targetSize);

    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if(newImage == nil) NSLog(@"could not scale image");


    return newImage ;
}
- (UIImage *)lc_imageByScalingToSize:(CGSize)targetSize {

    UIImage *sourceImage = self;
    UIImage *newImage = nil;

    //   CGSize imageSize = sourceImage.size;
    //   CGFloat width = imageSize.width;
    //   CGFloat height = imageSize.height;

    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;

    //   CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;

    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    // this is actually the interesting part:

    UIGraphicsBeginImageContext(targetSize);

    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if(newImage == nil) NSLog(@"could not scale image");


    return newImage ;
}
- (UIImage *)lc_imageRotatedByRadians:(CGFloat)radians
{
    return [self lc_imageRotatedByDegrees:RadiansToDegrees(radians)];
}
- (UIImage *)lc_imageRotatedByDegrees:(CGFloat)degrees
{
    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
    CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
    rotatedViewBox.transform = t;
    CGSize rotatedSize = rotatedViewBox.frame.size;

    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();

    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

    //   // Rotate the image context
    CGContextRotateCTM(bitmap, DegreesToRadians(degrees));

    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}

- (UIImage *)lc_keepScaleWithWidth:(float) newWidth
{
    float oldWidth = self.size.width;
    float oldHeight = self.size.height;
    float newHeight = newWidth / oldWidth * oldHeight;
    CGSize newSize = CGSizeMake(newWidth, newHeight);
    return [self lc_imageByScalingToSize:newSize];
}

- (UIImage *)lc_scaleWithOutDamageInTop:(CGFloat)top
                                left:(CGFloat)left
                              bottom:(CGFloat)bottom
                               right:(CGFloat)right;
{

    UIEdgeInsets insets = UIEdgeInsetsMake(top, left, bottom, right);
    UIImage *img2 = [self resizableImageWithCapInsets:insets];
    return img2;
}

- (UIImage *)lc_chnageToScale:(float)scaleSize
{
    UIGraphicsBeginImageContext(CGSizeMake(self.size.width*scaleSize,self.size.height*scaleSize));
    [self drawInRect:CGRectMake(0, 0, self.size.width * scaleSize, self.size.height *scaleSize)];
    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return scaledImage;
}

- (UIImage *)lc_centerClipBySize:(CGFloat)size
{
    CGFloat width = self.size.width;
    CGFloat height = self.size.height;
    CGFloat targetSize = 0;
    if (width > height) { //以中心区域的高度作为基准，裁剪方形图片
        targetSize = MIN(size, height);
    }
    else
    {
        targetSize = MIN(size, width);
    }

    CGFloat left = (width - targetSize) / 2.0;
    CGFloat top = (height - targetSize) / 2.0;
    CGRect rect = CGRectMake(left, top, size, size);
    return [self lc_imageAtRect:rect];
}

- (UIImage *)lc_centerScaleToSize:(CGSize)size {

    UIImage *image = [self lc_cutWithWideRate:size.width / size.height];
    //缩放比例
    float scale = size.width / image.width;
    image = [image lc_chnageToScale:scale];
    return image;
}

- (UIImage *)lc_cutWithWideRate:(CGFloat)rate {

    CGFloat x = 0.0;
    CGFloat y = 0.0;
    CGFloat w = 0.0;
    CGFloat h = 0.0;

    CGFloat imageSizeRate = self.width / self.height;
    if(imageSizeRate >= rate) {
        w = self.height * rate;
        h = self.height;
        x = (self.width - w) / 2;
        y = 0;
    }else {
        w = self.width;
        h = self.width / rate;
        x = 0;
        y = (self.height - h) / 2;
    }

    return [self lc_imageAtRect:CGRectMake(x, y, w, h)];
}

- (UIImage *)lc_imageScalingWithSize:(CGSize)size {

    CGFloat scaleWidth = self.size.width / size.width;
    CGFloat scaleHeight = self.size.height / size.height;
    CGFloat scale = MAX(scaleWidth, scaleHeight);

    return [UIImage imageWithCGImage:self.CGImage scale:scale orientation:UIImageOrientationUp];
}

- (UIImage *)lc_imageWithColor:(UIColor *)color
{
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, 0, self.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);
    CGContextSetBlendMode(context, kCGBlendModeNormal);
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    CGContextClipToMask(context, rect, self.CGImage);
    [color setFill];
    CGContextFillRect(context, rect);
    UIImage*newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

- (NSData *)compressToMaxDataSizeKBytes:(CGFloat)size{
    NSData * data = UIImageJPEGRepresentation(self, 1.0);
    CGFloat dataKBytes = data.length/1000.0;
    CGFloat maxQuality = 0.9f;
    CGFloat lastData = dataKBytes;
    while (dataKBytes > size && maxQuality > 0.01f) {
        maxQuality = maxQuality - 0.01f;
        data = UIImageJPEGRepresentation(self, maxQuality);
        dataKBytes = data.length / 1000.0;
        if (lastData == dataKBytes) {
            break;
        }else{
            lastData = dataKBytes;
        }
    }
    return data;
}
@end