//
//  UIImage+Orientation.m
//  iOS-Categories (https://github.com/shaojiankui/iOS-Categories)
//
//  Created by Jakey on 15/1/4.
//  Copyright (c) 2015年 www.skyfox.org. All rights reserved.
//

#import "UIImage+Orientation.h"

@implementation UIImage (Orientation)
/**
 *  @brief  修正图片的方向
 *
 *  @param srcImg 图片
 *
 *  @return 修正方向后的图片
 */
+ (UIImage *)fixOrientation:(UIImage *)srcImg {
    if (srcImg.imageOrientation == UIImageOrientationUp) return srcImg;
    CGAffineTransform transform = CGAffineTransformIdentity;
    switch (srcImg.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, srcImg.size.width, srcImg.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, srcImg.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, srcImg.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationUpMirrored:
            break;
    }
    switch (srcImg.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, srcImg.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, srcImg.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationDown:
        case UIImageOrientationLeft:
        case UIImageOrientationRight:
            break;
    }
    CGContextRef ctx = CGBitmapContextCreate(NULL, srcImg.size.width, srcImg.size.height,
                                             CGImageGetBitsPerComponent(srcImg.CGImage), 0,
                                             CGImageGetColorSpace(srcImg.CGImage),
                                             CGImageGetBitmapInfo(srcImg.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (srcImg.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            CGContextDrawImage(ctx, CGRectMake(0,0,srcImg.size.height,srcImg.size.width), srcImg.CGImage);
            break;
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,srcImg.size.width,srcImg.size.height), srcImg.CGImage);
            break;
    }
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

- (UIImage *)flip:(BOOL)isHorizontal {
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextClipToRect(ctx, rect);
    if (isHorizontal) {
        CGContextRotateCTM(ctx, M_PI);
        CGContextTranslateCTM(ctx, -rect.size.width, -rect.size.height);
    }
    CGContextDrawImage(ctx, rect, self.CGImage);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}
/**
 *  @brief  垂直翻转
 *
 *  @return  翻转后的图片
 */
- (UIImage *)flipVertical {
    return [self flip:NO];
}
/**
 *  @brief  水平翻转
 *
 *  @return 翻转后的图片
 */
- (UIImage *)flipHorizontal {
    return [self flip:YES];
}
/**
 *  @brief  旋转图片
 *
 *  @param degrees 弧度
 *
 *  @return 旋转后图片
 */
- (UIImage *)imageRotatedByRadians:(CGFloat)radians
{
    return [self imageRotatedByDegrees:[UIImage radiansToDegrees:radians]];
}
/**
 *  @brief  旋转图片
 *
 *  @param degrees 度
 *
 *  @return 旋转后图片
 */
- (UIImage *)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([UIImage 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, [UIImage 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;
    
}

/**
 *  @brief  角度转弧度
 *
 *  @param degrees 角度
 *
 *  @return 弧度
 */
+(CGFloat)degreesToRadians:(CGFloat)degrees
{
    return degrees * M_PI / 180;
}
/**
 *  @brief  弧度转角度
 *
 *  @param radians 弧度
 *
 *  @return 角度
 */
+(CGFloat)radiansToDegrees:(CGFloat)radians
{
    return radians * 180/M_PI;
}
@end