#import "ImageUtils.h"

@implementation ImageUtils

+ (UIImage *)cropImage:(UIImage *)image toRect:(CGRect)rect
{
  CGImageRef takenCGImage = image.CGImage;
  CGImageRef cropCGImage = CGImageCreateWithImageInRect(takenCGImage, rect);
  image = [UIImage imageWithCGImage:cropCGImage scale:image.scale orientation:image.imageOrientation];
  CGImageRelease(cropCGImage);
  return image;
}

+ (UIImage *)fixOrientation:(UIImage *)image
{
  if (image.imageOrientation == UIImageOrientationUp) {
    return image;
  }

  CGAffineTransform transform = CGAffineTransformIdentity;
  switch (image.imageOrientation) {
    case UIImageOrientationDown:
    case UIImageOrientationDownMirrored:
      transform = CGAffineTransformTranslate(transform, image.size.width, image.size.height);
      transform = CGAffineTransformRotate(transform, M_PI);
      break;

    case UIImageOrientationLeft:
    case UIImageOrientationLeftMirrored:
      transform = CGAffineTransformTranslate(transform, image.size.width, 0);
      transform = CGAffineTransformRotate(transform, M_PI_2);
      break;

    case UIImageOrientationRight:
    case UIImageOrientationRightMirrored:
      transform = CGAffineTransformTranslate(transform, 0, image.size.height);
      transform = CGAffineTransformRotate(transform, -M_PI_2);
      break;

    default:
      break;
  }

  switch (image.imageOrientation) {
    case UIImageOrientationUpMirrored:
    case UIImageOrientationDownMirrored:
      transform = CGAffineTransformTranslate(transform, image.size.width, 0);
      transform = CGAffineTransformScale(transform, -1, 1);
      break;

    case UIImageOrientationLeftMirrored:
    case UIImageOrientationRightMirrored:
      transform = CGAffineTransformTranslate(transform, image.size.height, 0);
      transform = CGAffineTransformScale(transform, -1, 1);
      break;

    default:
      break;
  }

  CGContextRef ctx = CGBitmapContextCreate(NULL, image.size.width, image.size.height, CGImageGetBitsPerComponent(image.CGImage), 0, CGImageGetColorSpace(image.CGImage), CGImageGetBitmapInfo(image.CGImage));
  CGContextConcatCTM(ctx, transform);
  switch (image.imageOrientation) {
    case UIImageOrientationLeft:
    case UIImageOrientationLeftMirrored:
    case UIImageOrientationRight:
    case UIImageOrientationRightMirrored:
      CGContextDrawImage(ctx, CGRectMake(0, 0, image.size.height, image.size.width), image.CGImage);
      break;

    default:
      CGContextDrawImage(ctx, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
      break;
  }

  CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
  UIImage *img = [UIImage imageWithCGImage:cgimg];
  CGContextRelease(ctx);
  CGImageRelease(cgimg);
  return img;
}

@end