//
//  UIImage+Utils.m
//  YYMobileFramework
//
//  Created by wuwei on 14/6/20.
//  Copyright (c) 2014年 YY Inc. All rights reserved.
//

#import "UIImage+Utils.h"
#import <ImageIO/ImageIO.h>

@implementation UIImage (Utils)
- (UIImage *)grayscaleImage
{
    CGFloat width = self.size.width;
    CGFloat height = self.size.height;
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    
    CGContextRef context = CGBitmapContextCreate(nil,
                                                 width,
                                                 height,
                                                 8,
                                                 0,
                                                 colorSpace,
                                                 kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedLast);
    CGColorSpaceRelease(colorSpace);

    if (context == NULL) {
        return nil;
    }
    
    CGContextDrawImage(context,  CGRectMake(0, 0, width, height), self.CGImage);
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    UIImage *grayscaleImage = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    CGContextRelease(context);
    
    return grayscaleImage;
}


- (UIImage *)imageBlendInGray {
 
    UIGraphicsBeginImageContext(self.size);
    CGRect bounds = CGRectMake(0, 0, self.size.width, self.size.height);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextFillRect(context, bounds);
    [self drawInRect:bounds blendMode:kCGBlendModeLuminosity alpha:1.0f];
    [self drawInRect:bounds blendMode:kCGBlendModeDestinationIn alpha:1.0f];
    UIImage *newImg = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return newImg;
}



- (UIImage *)imageWithBlendMode:(CGBlendMode)blendMode {
    
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0f);
    CGRect bounds = CGRectMake(0, 0, self.size.width, self.size.height);
    UIRectFill(bounds);
    
    [self drawInRect:bounds blendMode:blendMode alpha:1.0f];
    
    if (blendMode != kCGBlendModeDestinationIn) {
        [self drawInRect:bounds blendMode:kCGBlendModeDestinationIn alpha:1.0f];
    }
    UIImage *newImg = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImg;
}

+ (UIImage *)imageWithColor:(UIColor *)color
{
    return [self imageWithColor:color size:CGSizeMake(1, 1)];
}

+ (UIImage *)imageWithColor:(UIColor *)color size:(CGSize)size {
    if (!color || size.width <= 0 || size.height <= 0) return nil;
    CGRect rect = CGRectMake(0.0f, 0.0f, size.width + 1, size.height);
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, color.CGColor);
    CGContextFillRect(context, rect);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

+ (UIImage *)fixOrientation:(UIImage *)aImage {
    
    // No-op if the orientation is already correct
    if (aImage.imageOrientation == UIImageOrientationUp)
        return aImage;
    
    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;
    
    switch (aImage.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
            
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
            
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        default:
            break;
    }
    
    switch (aImage.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
            
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        default:
            break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
                                             CGImageGetBitsPerComponent(aImage.CGImage), 0,
                                             CGImageGetColorSpace(aImage.CGImage),
                                             CGImageGetBitmapInfo(aImage.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (aImage.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
            break;
            
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
            break;
    }
    
    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

- (UIImage *)imageWithColor:(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 *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return image;
    
}

//异步生成纯色圆角图片
- (void)imageWithSize:(CGSize)size radius:(CGFloat)radius backColor:(UIColor *)backColor completion:(void(^)(UIImage *image))completion {
    // 异步绘制裁切
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        // 利用绘图建立上下文
        UIGraphicsBeginImageContextWithOptions(size, true, 0);
        CGRect rect = CGRectMake(0, 0, size.width, size.height);
        // 填充颜色
        [backColor setFill];
        UIRectFill(rect);
        //        // 贝塞尔裁切
        //        UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:radius];
        //        [path addClip];
        //        [self drawInRect:rect];
        
        // 获取结果
        UIImage *resultImage = [UIGraphicsGetImageFromCurrentImageContext() circularImage];
        // 关闭上下文
        UIGraphicsEndImageContext();
        // 主队列回调
        dispatch_async(dispatch_get_main_queue(), ^{
            completion(resultImage);
        });
    });
    
}

- (UIImage *)circularImage {
    // 1. 开启图形上下文
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0);
    
    // 2. 描述路径
    
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, self.size.width, self.size.height) byRoundingCorners:UIRectCornerTopLeft|UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(self.size.width, self.size.height)];
    //    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, self.size.width, self.size.height)];
    
    // 3. 添加裁减区域
    [path addClip];
    
    // 4. 绘制图片
    [self drawAtPoint:CGPointZero];
    
    // 5. 从上下文获取图片
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    
    // 6. 关闭上下文
    UIGraphicsEndImageContext();
    
    // 7. 设置图片
    return image;
}

+ (UIImage *)gradientColorImageFromColors:(NSArray<UIColor *> *)colors gradientType:(GradientType)gradientType imgSize:(CGSize)imgSize{
    
    NSMutableArray *ar = [NSMutableArray array];
    for(UIColor *c in colors) {
        [ar addObject:(id)c.CGColor];
    }
    UIGraphicsBeginImageContextWithOptions(imgSize, YES, 1);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSaveGState(context);
    CGColorSpaceRef colorSpace = CGColorGetColorSpace([[colors lastObject] CGColor]);
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (CFArrayRef)ar, NULL);
    CGPoint start;
    CGPoint end;
    switch (gradientType) {
        case GradientTypeTopToBottom:
            start = CGPointMake(0.0, 0.0);
            end = CGPointMake(0.0, imgSize.height);
            break;
        case GradientTypeLeftToRight:
            start = CGPointMake(0.0, 0.0);
            end = CGPointMake(imgSize.width, 0.0);
            break;
        case GradientTypeUpleftToLowright:
            start = CGPointMake(0.0, 0.0);
            end = CGPointMake(imgSize.width, imgSize.height);
            break;
        case GradientTypeUprightToLowleft:
            start = CGPointMake(imgSize.width, 0.0);
            end = CGPointMake(0.0, imgSize.height);
            break;
        default:
            break;
    }
    CGContextDrawLinearGradient(context, gradient, start, end, kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    CGGradientRelease(gradient);
    CGContextRestoreGState(context);
    CGColorSpaceRelease(colorSpace);
    UIGraphicsEndImageContext();
    
    return image;
}

- (UIImage *)setCornerWithRadius:(CGFloat)radius andSize:(CGSize)size {
    //开启图形上下文
    UIGraphicsBeginImageContext(size);
    //绘制圆角矩形
    CGRect rect = CGRectMake(0, 0, size.width, size.height);
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(radius, radius)];
    //将Path添加到上下文中
    CGContextAddPath(UIGraphicsGetCurrentContext(), path.CGPath);
    //裁剪上下文
    CGContextClip(UIGraphicsGetCurrentContext());
    //将图片绘制到上下文中
    [self drawInRect:rect];
    //设置绘制模式
    CGContextDrawPath(UIGraphicsGetCurrentContext(), kCGPathStroke);
    //获取图片
    UIImage *output = UIGraphicsGetImageFromCurrentImageContext();
    //关闭上下文
    UIGraphicsEndImageContext();
    //返回裁剪好的图片
    return output;
}

@end