BITHockeyHelper.m

/*
 * Author: Andreas Linde <mail@andreaslinde.de>
 *
 * Copyright (c) 2012-2014 HockeyApp, Bit Stadium GmbH.
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */


#import "BITHockeyHelper.h"
#import "BITKeychainUtils.h"
#import "HockeySDK.h"
#import "HockeySDKPrivate.h"
#if !defined (HOCKEYSDK_CONFIGURATION_ReleaseCrashOnly) && !defined (HOCKEYSDK_CONFIGURATION_ReleaseCrashOnlyExtensions)
#import <QuartzCore/QuartzCore.h>
#endif

#pragma mark NSString helpers

NSString *bit_URLEncodedString(NSString *inputString) {
  
  // Requires iOS 7
  if ([inputString respondsToSelector:@selector(stringByAddingPercentEncodingWithAllowedCharacters:)]) {
    return [inputString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet characterSetWithCharactersInString:@"!*'();:@&=+$,/?%#[]"].invertedSet];
    
  } else {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    return CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                                     (__bridge CFStringRef)inputString,
                                                                     NULL,
                                                                     CFSTR("!*'();:@&=+$,/?%#[]"),
                                                                     kCFStringEncodingUTF8)
                             );
#pragma clang diagnostic pop
  }
}

NSString *bit_base64String(NSData * data, unsigned long length) {
  SEL base64EncodingSelector = NSSelectorFromString(@"base64EncodedStringWithOptions:");
  if ([data respondsToSelector:base64EncodingSelector]) {
    return [data base64EncodedStringWithOptions:0];
  } else {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    return [data base64Encoding];
#pragma clang diagnostic pop
  }
}

NSString *bit_settingsDir(void) {
  static NSString *settingsDir = nil;
  static dispatch_once_t predSettingsDir;
  
  dispatch_once(&predSettingsDir, ^{
    NSFileManager *fileManager = [[NSFileManager alloc] init];
    
    // temporary directory for crashes grabbed from PLCrashReporter
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    settingsDir = [[paths objectAtIndex:0] stringByAppendingPathComponent:BITHOCKEY_IDENTIFIER];
    
    if (![fileManager fileExistsAtPath:settingsDir]) {
      NSDictionary *attributes = [NSDictionary dictionaryWithObject: [NSNumber numberWithUnsignedLong: 0755] forKey: NSFilePosixPermissions];
      NSError *theError = NULL;
      
      [fileManager createDirectoryAtPath:settingsDir withIntermediateDirectories: YES attributes: attributes error: &theError];
    }
  });
  
  return settingsDir;
}

BOOL bit_validateEmail(NSString *email) {
  NSString *emailRegex =
  @"(?:[a-z0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[a-z0-9!#$%\\&'*+/=?\\^_`{|}"
  @"~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\"
  @"x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-"
  @"z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?:25[0-5"
  @"]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-"
  @"9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21"
  @"-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])";
  NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES[c] %@", emailRegex];
  
  return [emailTest evaluateWithObject:email];
}

NSString *bit_keychainHockeySDKServiceName(void) {
  static NSString *serviceName = nil;
  static dispatch_once_t predServiceName;
  
  dispatch_once(&predServiceName, ^{
    serviceName = [NSString stringWithFormat:@"%@.HockeySDK", bit_mainBundleIdentifier()];
  });
  
  return serviceName;
}

NSComparisonResult bit_versionCompare(NSString *stringA, NSString *stringB) {
  // Extract plain version number from self
  NSString *plainSelf = stringA;
  NSRange letterRange = [plainSelf rangeOfCharacterFromSet: [NSCharacterSet letterCharacterSet]];
  if (letterRange.length)
    plainSelf = [plainSelf substringToIndex: letterRange.location];
	
  // Extract plain version number from other
  NSString *plainOther = stringB;
  letterRange = [plainOther rangeOfCharacterFromSet: [NSCharacterSet letterCharacterSet]];
  if (letterRange.length)
    plainOther = [plainOther substringToIndex: letterRange.location];
	
  // Compare plain versions
  NSComparisonResult result = [plainSelf compare:plainOther options:NSNumericSearch];
	
  // If plain versions are equal, compare full versions
  if (result == NSOrderedSame)
    result = [stringA compare:stringB options:NSNumericSearch];
	
  // Done
  return result;
}

NSString *bit_mainBundleIdentifier(void) {
  return [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleIdentifier"];
}

NSString *bit_encodeAppIdentifier(NSString *inputString) {
  return (inputString ? bit_URLEncodedString(inputString) : bit_URLEncodedString(bit_mainBundleIdentifier()));
}

NSString *bit_appName(NSString *placeHolderString) {
  NSString *appName = [[[NSBundle mainBundle] localizedInfoDictionary] objectForKey:@"CFBundleDisplayName"];
  if (!appName)
    appName = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleDisplayName"];
  if (!appName)
    appName = [[[NSBundle mainBundle] localizedInfoDictionary] objectForKey:@"CFBundleName"];
  if (!appName)
    appName = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleName"] ?: placeHolderString;
  
  return appName;
}

NSString *bit_UUIDPreiOS6(void) {
  // Create a new UUID
  CFUUIDRef uuidObj = CFUUIDCreate(nil);
  
  // Get the string representation of the UUID
  NSString *resultUUID = (NSString*)CFBridgingRelease(CFUUIDCreateString(nil, uuidObj));
  CFRelease(uuidObj);
  
  return resultUUID;
}

NSString *bit_UUID(void) {
  NSString *resultUUID = nil;
  
  id uuidClass = NSClassFromString(@"NSUUID");
  if (uuidClass) {
    resultUUID = [[NSUUID UUID] UUIDString];
  } else {
    resultUUID = bit_UUIDPreiOS6();
  }
  
  return resultUUID;
}

NSString *bit_appAnonID(BOOL forceNewAnonID) {
  static NSString *appAnonID = nil;
  static dispatch_once_t predAppAnonID;
  __block NSError *error = nil;
  NSString *appAnonIDKey = @"appAnonID";
  
  if (forceNewAnonID) {
    appAnonID = bit_UUID();
    // store this UUID in the keychain (on this device only) so we can be sure to always have the same ID upon app startups
    if (appAnonID) {
      // add to keychain in a background thread, since we got reports that storing to the keychain may take several seconds sometimes and cause the app to be killed
      // and we don't care about the result anyway
      dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
        [BITKeychainUtils storeUsername:appAnonIDKey
                            andPassword:appAnonID
                         forServiceName:bit_keychainHockeySDKServiceName()
                         updateExisting:YES
                          accessibility:kSecAttrAccessibleAlwaysThisDeviceOnly
                                  error:&error];
      });
    }
  } else {
    dispatch_once(&predAppAnonID, ^{
      // first check if we already have an install string in the keychain
      appAnonID = [BITKeychainUtils getPasswordForUsername:appAnonIDKey andServiceName:bit_keychainHockeySDKServiceName() error:&error];
      
      if (!appAnonID) {
        appAnonID = bit_UUID();
        // store this UUID in the keychain (on this device only) so we can be sure to always have the same ID upon app startups
        if (appAnonID) {
          // add to keychain in a background thread, since we got reports that storing to the keychain may take several seconds sometimes and cause the app to be killed
          // and we don't care about the result anyway
          dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
            [BITKeychainUtils storeUsername:appAnonIDKey
                                andPassword:appAnonID
                             forServiceName:bit_keychainHockeySDKServiceName()
                             updateExisting:YES
                              accessibility:kSecAttrAccessibleAlwaysThisDeviceOnly
                                      error:&error];
          });
        }
      }
    });
  }
  
  return appAnonID;
}

BOOL bit_isPreiOS7Environment(void) {
  static BOOL isPreiOS7Environment = YES;
  static dispatch_once_t checkOS;
  
  dispatch_once(&checkOS, ^{
    // NSFoundationVersionNumber_iOS_6_1 = 993.00
    // We hardcode this, so compiling with iOS 6 is possible while still being able to detect the correct environment
    
    // runtime check according to
    // https://developer.apple.com/library/prerelease/ios/documentation/UserExperience/Conceptual/TransitionGuide/SupportingEarlieriOS.html
    if (floor(NSFoundationVersionNumber) <= 993.00) {
      isPreiOS7Environment = YES;
    } else {
      isPreiOS7Environment = NO;
    }
  });
  
  return isPreiOS7Environment;
}

BOOL bit_isPreiOS8Environment(void) {
  static BOOL isPreiOS8Environment = YES;
  static dispatch_once_t checkOS8;
  
  dispatch_once(&checkOS8, ^{
    // NSFoundationVersionNumber_iOS_7_1 = 1047.25
    // We hardcode this, so compiling with iOS 7 is possible while still being able to detect the correct environment

    // runtime check according to
    // https://developer.apple.com/library/prerelease/ios/documentation/UserExperience/Conceptual/TransitionGuide/SupportingEarlieriOS.html
    if (floor(NSFoundationVersionNumber) <= 1047.25) {
      isPreiOS8Environment = YES;
    } else {
      isPreiOS8Environment = NO;
    }
  });
  
  return isPreiOS8Environment;
}

BOOL bit_isAppStoreReceiptSandbox(void) {
#if TARGET_IPHONE_SIMULATOR
  return NO;
#else
  NSURL *appStoreReceiptURL = NSBundle.mainBundle.appStoreReceiptURL;
  NSString *appStoreReceiptLastComponent = appStoreReceiptURL.lastPathComponent;
  
  BOOL isSandboxReceipt = [appStoreReceiptLastComponent isEqualToString:@"sandboxReceipt"];
  return isSandboxReceipt;
#endif
}

BOOL bit_hasEmbeddedMobileProvision(void) {
  BOOL hasEmbeddedMobileProvision = [[NSBundle mainBundle] pathForResource:@"embedded" ofType:@"mobileprovision"];
  return hasEmbeddedMobileProvision;
}

BOOL bit_isRunningInTestFlightEnvironment(void) {
#if TARGET_IPHONE_SIMULATOR
  return NO;
#else
  if (bit_isAppStoreReceiptSandbox() && !bit_hasEmbeddedMobileProvision()) {
    return YES;
  }
  return NO;
#endif
}

BOOL bit_isRunningInAppStoreEnvironment(void) {
#if TARGET_IPHONE_SIMULATOR
  return NO;
#else
  if (bit_isAppStoreReceiptSandbox() || bit_hasEmbeddedMobileProvision()) {
    return NO;
  }
  return YES;
#endif
}

BOOL bit_isRunningInAppExtension(void) {
  static BOOL isRunningInAppExtension = NO;
  static dispatch_once_t checkAppExtension;
  
  dispatch_once(&checkAppExtension, ^{
    isRunningInAppExtension = ([[[NSBundle mainBundle] executablePath] rangeOfString:@".appex/"].location != NSNotFound);
  });
  
  return isRunningInAppExtension;
}

#if !defined (HOCKEYSDK_CONFIGURATION_ReleaseCrashOnly) && !defined (HOCKEYSDK_CONFIGURATION_ReleaseCrashOnlyExtensions)

/**
 Find a valid app icon filename that points to a proper app icon image
 
 @param icons NSArray with app icon filenames
 
 @return NSString with the valid app icon or nil if none found
 */
NSString *bit_validAppIconStringFromIcons(NSBundle *resourceBundle, NSArray *icons) {
  if (!icons) return nil;
  if (![icons isKindOfClass:[NSArray class]]) return nil;
  
  BOOL useHighResIcon = NO;
  BOOL useiPadIcon = NO;
  if ([UIScreen mainScreen].scale == 2.0f) useHighResIcon = YES;
  if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) useiPadIcon = YES;
  
  NSString *currentBestMatch = nil;
  float currentBestMatchHeight = 0;
  float bestMatchHeight = 0;

  if (bit_isPreiOS7Environment()) {
    bestMatchHeight = useiPadIcon ? (useHighResIcon ? 144 : 72) : (useHighResIcon ? 114 : 57);
  } else {
    bestMatchHeight = useiPadIcon ? (useHighResIcon ? 152 : 76) : 120;
  }
  
  for(NSString *icon in icons) {
    // Don't use imageNamed, otherwise unit tests won't find the fixture icon
    // and using imageWithContentsOfFile doesn't load @2x files with absolut paths (required in tests)

    NSString *iconPathExtension = ([[icon pathExtension] length] > 0) ? [icon pathExtension] : @"png";
    NSMutableArray *iconFilenameVariants = [NSMutableArray new];
    
    [iconFilenameVariants addObject:[icon stringByDeletingPathExtension]];
    [iconFilenameVariants addObject:[NSString stringWithFormat:@"%@@2x", [icon stringByDeletingPathExtension]]];
    
    for (NSString *iconFilename in iconFilenameVariants) {
      // this call already covers "~ipad" files
      NSString *iconPath = [resourceBundle pathForResource:iconFilename ofType:iconPathExtension];
      
      NSData *imgData = [[NSData alloc] initWithContentsOfFile:iconPath];
    
      UIImage *iconImage = [[UIImage alloc] initWithData:imgData];
      
      if (iconImage) {
        if (iconImage.size.height == bestMatchHeight) {
          return iconFilename;
        } else if (iconImage.size.height < bestMatchHeight &&
                   iconImage.size.height > currentBestMatchHeight) {
          currentBestMatchHeight = iconImage.size.height;
          currentBestMatch = iconFilename;
        }
      }
    }
  }
  
  return currentBestMatch;
}

NSString *bit_validAppIconFilename(NSBundle *bundle, NSBundle *resourceBundle) {
  NSString *iconFilename = nil;
  NSArray *icons = nil;
  
  icons = [bundle objectForInfoDictionaryKey:@"CFBundleIconFiles"];
  iconFilename = bit_validAppIconStringFromIcons(resourceBundle, icons);
  
  if (!iconFilename) {
    icons = [bundle objectForInfoDictionaryKey:@"CFBundleIcons"];
    if (icons && [icons isKindOfClass:[NSDictionary class]]) {
      icons = [icons valueForKeyPath:@"CFBundlePrimaryIcon.CFBundleIconFiles"];
    }
    iconFilename = bit_validAppIconStringFromIcons(resourceBundle, icons);
  }
  
  // we test iPad structure anyway and use it if we find a result and don't have another one yet
  if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
    icons = [bundle objectForInfoDictionaryKey:@"CFBundleIcons~ipad"];
    if (icons && [icons isKindOfClass:[NSDictionary class]]) {
      icons = [icons valueForKeyPath:@"CFBundlePrimaryIcon.CFBundleIconFiles"];
    }
    NSString *iPadIconFilename = bit_validAppIconStringFromIcons(resourceBundle, icons);
    if (iPadIconFilename && !iconFilename) {
      iconFilename = iPadIconFilename;
    }
  }

  if (!iconFilename) {
    NSString *tempFilename = [bundle objectForInfoDictionaryKey:@"CFBundleIconFile"];
    if (tempFilename) {
      iconFilename = bit_validAppIconStringFromIcons(resourceBundle, @[tempFilename]);
    }
  }
  
  if (!iconFilename) {
    iconFilename = bit_validAppIconStringFromIcons(resourceBundle, @[@"Icon.png"]);
  }
  
  return iconFilename;
}

#pragma mark UIImage private helpers

static void bit_addRoundedRectToPath(CGRect rect, CGContextRef context, CGFloat ovalWidth, CGFloat ovalHeight);
static CGContextRef bit_MyOpenBitmapContext(int pixelsWide, int pixelsHigh);
static CGImageRef bit_CreateGradientImage(int pixelsWide, int pixelsHigh, float fromAlpha, float toAlpha);
static BOOL bit_hasAlpha(UIImage *inputImage);
UIImage *bit_imageWithAlpha(UIImage *inputImage);
UIImage *bit_addGlossToImage(UIImage *inputImage);

// Adds a rectangular path to the given context and rounds its corners by the given extents
// Original author: Björn Sållarp. Used with permission. See: http://blog.sallarp.com/iphone-uiimage-round-corners/
void bit_addRoundedRectToPath(CGRect rect, CGContextRef context, CGFloat ovalWidth, CGFloat ovalHeight) {
  if (ovalWidth == 0 || ovalHeight == 0) {
    CGContextAddRect(context, rect);
    return;
  }
  CGContextSaveGState(context);
  CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
  CGContextScaleCTM(context, ovalWidth, ovalHeight);
  CGFloat fw = CGRectGetWidth(rect) / ovalWidth;
  CGFloat fh = CGRectGetHeight(rect) / ovalHeight;
  CGContextMoveToPoint(context, fw, fh/2);
  CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);
  CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1);
  CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1);
  CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1);
  CGContextClosePath(context);
  CGContextRestoreGState(context);
}

CGImageRef bit_CreateGradientImage(int pixelsWide, int pixelsHigh, float fromAlpha, float toAlpha) {
  CGImageRef theCGImage = NULL;
  
  // gradient is always black-white and the mask must be in the gray colorspace
  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
  
  // create the bitmap context
  CGContextRef gradientBitmapContext = CGBitmapContextCreate(NULL, pixelsWide, pixelsHigh,
                                                             8, 0, colorSpace, (CGBitmapInfo)kCGImageAlphaNone);
  
  // define the start and end grayscale values (with the alpha, even though
  // our bitmap context doesn't support alpha the gradient requires it)
  CGFloat colors[] = {toAlpha, 1.0, fromAlpha, 1.0};
  
  // create the CGGradient and then release the gray color space
  CGGradientRef grayScaleGradient = CGGradientCreateWithColorComponents(colorSpace, colors, NULL, 2);
  CGColorSpaceRelease(colorSpace);
  
  // create the start and end points for the gradient vector (straight down)
  CGPoint gradientEndPoint = CGPointZero;
  CGPoint gradientStartPoint = CGPointMake(0, pixelsHigh);
  
  // draw the gradient into the gray bitmap context
  CGContextDrawLinearGradient(gradientBitmapContext, grayScaleGradient, gradientStartPoint,
                              gradientEndPoint, kCGGradientDrawsAfterEndLocation);
  CGGradientRelease(grayScaleGradient);
  
  // convert the context into a CGImageRef and release the context
  theCGImage = CGBitmapContextCreateImage(gradientBitmapContext);
  CGContextRelease(gradientBitmapContext);
  
  // return the imageref containing the gradient
  return theCGImage;
}

CGContextRef bit_MyOpenBitmapContext(int pixelsWide, int pixelsHigh) {
  CGSize size = CGSizeMake(pixelsWide, pixelsHigh);
  UIGraphicsBeginImageContextWithOptions(size, NO, 0.0);
  
  return UIGraphicsGetCurrentContext();
}


// Returns true if the image has an alpha layer
BOOL bit_hasAlpha(UIImage *inputImage) {
  CGImageAlphaInfo alpha = CGImageGetAlphaInfo(inputImage.CGImage);
  return (alpha == kCGImageAlphaFirst ||
          alpha == kCGImageAlphaLast ||
          alpha == kCGImageAlphaPremultipliedFirst ||
          alpha == kCGImageAlphaPremultipliedLast);
}

// Returns a copy of the given image, adding an alpha channel if it doesn't already have one
UIImage *bit_imageWithAlpha(UIImage *inputImage) {
  if (bit_hasAlpha(inputImage)) {
    return inputImage;
  }
  
  CGImageRef imageRef = inputImage.CGImage;
  size_t width = CGImageGetWidth(imageRef) * inputImage.scale;
  size_t height = CGImageGetHeight(imageRef) * inputImage.scale;
  
  // The bitsPerComponent and bitmapInfo values are hard-coded to prevent an "unsupported parameter combination" error
  CGContextRef offscreenContext = CGBitmapContextCreate(NULL,
                                                        width,
                                                        height,
                                                        8,
                                                        0,
                                                        CGImageGetColorSpace(imageRef),
                                                        kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedFirst);
  
  // Draw the image into the context and retrieve the new image, which will now have an alpha layer
  CGContextDrawImage(offscreenContext, CGRectMake(0, 0, width, height), imageRef);
  CGImageRef imageRefWithAlpha = CGBitmapContextCreateImage(offscreenContext);
  UIImage *imageWithAlpha = [UIImage imageWithCGImage:imageRefWithAlpha];
  
  // Clean up
  CGContextRelease(offscreenContext);
  CGImageRelease(imageRefWithAlpha);
  
  return imageWithAlpha;
}

UIImage *bit_addGlossToImage(UIImage *inputImage) {
  UIGraphicsBeginImageContextWithOptions(inputImage.size, NO, 0.0);
  
  [inputImage drawAtPoint:CGPointZero];
  UIImage *iconGradient = bit_imageNamed(@"IconGradient.png", BITHOCKEYSDK_BUNDLE);
  [iconGradient drawInRect:CGRectMake(0, 0, inputImage.size.width, inputImage.size.height) blendMode:kCGBlendModeNormal alpha:0.5];
  
  UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  return result;
}

#pragma mark UIImage helpers

UIImage *bit_imageToFitSize(UIImage *inputImage, CGSize fitSize, BOOL honorScaleFactor) {
  
  if (!inputImage){
    return nil;
  }
  
  float imageScaleFactor = 1.0;
  if (honorScaleFactor) {
    if ([inputImage respondsToSelector:@selector(scale)]) {
      imageScaleFactor = [inputImage scale];
    }
  }
  
  float sourceWidth = [inputImage size].width * imageScaleFactor;
  float sourceHeight = [inputImage size].height * imageScaleFactor;
  float targetWidth = fitSize.width;
  float targetHeight = fitSize.height;
  
  // Calculate aspect ratios
  float sourceRatio = sourceWidth / sourceHeight;
  float targetRatio = targetWidth / targetHeight;
  
  // Determine what side of the source image to use for proportional scaling
  BOOL scaleWidth = (sourceRatio <= targetRatio);
  // Deal with the case of just scaling proportionally to fit, without cropping
  scaleWidth = !scaleWidth;
  
  // Proportionally scale source image
  float scalingFactor, scaledWidth, scaledHeight;
  if (scaleWidth) {
    scalingFactor = 1.0 / sourceRatio;
    scaledWidth = targetWidth;
    scaledHeight = round(targetWidth * scalingFactor);
  } else {
    scalingFactor = sourceRatio;
    scaledWidth = round(targetHeight * scalingFactor);
    scaledHeight = targetHeight;
  }
  
  // Calculate compositing rectangles
  CGRect sourceRect, destRect;
  sourceRect = CGRectMake(0, 0, sourceWidth, sourceHeight);
  destRect = CGRectMake(0, 0, scaledWidth, scaledHeight);
  
  // Create appropriately modified image.
  UIImage *image = nil;
  UIGraphicsBeginImageContextWithOptions(destRect.size, NO, honorScaleFactor ? 0.0 : 1.0); // 0.0 for scale means "correct scale for device's main screen".
  CGImageRef sourceImg = CGImageCreateWithImageInRect([inputImage CGImage], sourceRect); // cropping happens here.
  image = [UIImage imageWithCGImage:sourceImg scale:0.0 orientation:inputImage.imageOrientation]; // create cropped UIImage.
  [image drawInRect:destRect]; // the actual scaling happens here, and orientation is taken care of automatically.
  CGImageRelease(sourceImg);
  image = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  if (!image) {
    // Try older method.
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL,  scaledWidth, scaledHeight, 8, (fitSize.width * 4),
                                                 colorSpace, (CGBitmapInfo)kCGImageAlphaPremultipliedLast);
    sourceImg = CGImageCreateWithImageInRect([inputImage CGImage], sourceRect);
    CGContextDrawImage(context, destRect, sourceImg);
    CGImageRelease(sourceImg);
    CGImageRef finalImage = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    image = [UIImage imageWithCGImage:finalImage];
    CGImageRelease(finalImage);
  }
  
  return image;
}


UIImage *bit_reflectedImageWithHeight(UIImage *inputImage, NSUInteger height, float fromAlpha, float toAlpha) {
  if(height == 0)
    return nil;
  
  // create a bitmap graphics context the size of the image
  CGContextRef mainViewContentContext = bit_MyOpenBitmapContext(inputImage.size.width, (int)height);
  
  // create a 2 bit CGImage containing a gradient that will be used for masking the
  // main view content to create the 'fade' of the reflection.  The CGImageCreateWithMask
  // function will stretch the bitmap image as required, so we can create a 1 pixel wide gradient
  CGImageRef gradientMaskImage = bit_CreateGradientImage(1, (int)height, fromAlpha, toAlpha);
  
  // create an image by masking the bitmap of the mainView content with the gradient view
  // then release the  pre-masked content bitmap and the gradient bitmap
  CGContextClipToMask(mainViewContentContext, CGRectMake(0.0, 0.0, inputImage.size.width, height), gradientMaskImage);
  CGImageRelease(gradientMaskImage);
  
  // draw the image into the bitmap context
  CGContextDrawImage(mainViewContentContext, CGRectMake(0, 0, inputImage.size.width, inputImage.size.height), inputImage.CGImage);
  
  // convert the finished reflection image to a UIImage
  UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext(); // returns autoreleased
  UIGraphicsEndImageContext();
  
  return theImage;
}


UIImage *bit_newWithContentsOfResolutionIndependentFile(NSString * path) {
  if ([UIScreen instancesRespondToSelector:@selector(scale)] && (int)[[UIScreen mainScreen] scale] == 2.0) {
    NSString *path2x = [[path stringByDeletingLastPathComponent]
                        stringByAppendingPathComponent:[NSString stringWithFormat:@"%@@2x.%@",
                                                        [[path lastPathComponent] stringByDeletingPathExtension],
                                                        [path pathExtension]]];
    
    if ([[NSFileManager defaultManager] fileExistsAtPath:path2x]) {
      return [[UIImage alloc] initWithContentsOfFile:path2x];
    }
  }
  
  return [[UIImage alloc] initWithContentsOfFile:path];
}


UIImage *bit_imageWithContentsOfResolutionIndependentFile(NSString *path) {
  return bit_newWithContentsOfResolutionIndependentFile(path);
}


UIImage *bit_imageNamed(NSString *imageName, NSString *bundleName) {
  NSString *resourcePath = [[NSBundle bundleForClass:[BITHockeyManager class]] resourcePath];
  NSString *bundlePath = [resourcePath stringByAppendingPathComponent:bundleName];
  NSString *imagePath = [bundlePath stringByAppendingPathComponent:imageName];
  return bit_imageWithContentsOfResolutionIndependentFile(imagePath);
}



// Creates a copy of this image with rounded corners
// If borderSize is non-zero, a transparent border of the given size will also be added
// Original author: Björn Sållarp. Used with permission. See: http://blog.sallarp.com/iphone-uiimage-round-corners/
UIImage *bit_roundedCornerImage(UIImage *inputImage, NSInteger cornerSize, NSInteger borderSize) {
  // If the image does not have an alpha layer, add one
  
  UIImage *roundedImage = nil;
  UIGraphicsBeginImageContextWithOptions(inputImage.size, NO, 0.0); // 0.0 for scale means "correct scale for device's main screen".
  CGImageRef sourceImg = CGImageCreateWithImageInRect([inputImage CGImage], CGRectMake(0, 0, inputImage.size.width * inputImage.scale, inputImage.size.height * inputImage.scale)); // cropping happens here.
  
  // Create a clipping path with rounded corners
  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextBeginPath(context);
  bit_addRoundedRectToPath(CGRectMake(borderSize, borderSize, inputImage.size.width - borderSize * 2, inputImage.size.height - borderSize * 2), context, cornerSize, cornerSize);
  CGContextClosePath(context);
  CGContextClip(context);
  
  roundedImage = [UIImage imageWithCGImage:sourceImg scale:0.0 orientation:inputImage.imageOrientation]; // create cropped UIImage.
  [roundedImage drawInRect:CGRectMake(0, 0, inputImage.size.width, inputImage.size.height)]; // the actual scaling happens here, and orientation is taken care of automatically.
  CGImageRelease(sourceImg);
  roundedImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  if (!roundedImage) {
    // Try older method.
    UIImage *image = bit_imageWithAlpha(inputImage);
    
    // Build a context that's the same dimensions as the new size
    context = CGBitmapContextCreate(NULL,
                                    image.size.width,
                                    image.size.height,
                                    CGImageGetBitsPerComponent(image.CGImage),
                                    0,
                                    CGImageGetColorSpace(image.CGImage),
                                    CGImageGetBitmapInfo(image.CGImage));
    
    // Create a clipping path with rounded corners
    CGContextBeginPath(context);
    bit_addRoundedRectToPath(CGRectMake(borderSize, borderSize, image.size.width - borderSize * 2, image.size.height - borderSize * 2), context, cornerSize, cornerSize);
    CGContextClosePath(context);
    CGContextClip(context);
    
    // Draw the image to the context; the clipping path will make anything outside the rounded rect transparent
    CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
    
    // Create a CGImage from the context
    CGImageRef clippedImage = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    
    // Create a UIImage from the CGImage
    roundedImage = [UIImage imageWithCGImage:clippedImage];
    CGImageRelease(clippedImage);
  }
  
  return roundedImage;
}

UIImage *bit_appIcon() {
  NSString *iconString = nil;
  NSArray *icons = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleIconFiles"];
  if (!icons) {
    icons = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleIcons"];
    if ((icons) && ([icons isKindOfClass:[NSDictionary class]])) {
      icons = [icons valueForKeyPath:@"CFBundlePrimaryIcon.CFBundleIconFiles"];
    }
    
    if (!icons) {
      iconString = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleIconFile"];
      if (!iconString) {
        iconString = @"Icon.png";
      }
    }
  }
  
  if (icons) {
    BOOL useHighResIcon = NO;
    if ([UIScreen mainScreen].scale == 2.0f) useHighResIcon = YES;
    
    for(NSString *icon in icons) {
      iconString = icon;
      UIImage *iconImage = [UIImage imageNamed:icon];
      
      if (iconImage.size.height == 57 && !useHighResIcon) {
        // found!
        break;
      }
      if (iconImage.size.height == 114 && useHighResIcon) {
        // found!
        break;
      }
    }
  }
  
  BOOL addGloss = YES;
  NSNumber *prerendered = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"UIPrerenderedIcon"];
  if (prerendered) {
    addGloss = ![prerendered boolValue];
  }
  
  if (addGloss) {
    return bit_addGlossToImage([UIImage imageNamed:iconString]);
  } else {
    return [UIImage imageNamed:iconString];
  }
}

UIImage *bit_screenshot(void) {
  // Create a graphics context with the target size
  CGSize imageSize = [[UIScreen mainScreen] bounds].size;
  BOOL isLandscapeLeft = [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeLeft;
  BOOL isLandscapeRight = [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeRight;
  BOOL isUpsideDown = [UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown;
  
  BOOL needsRotation = NO;
  
  if ((isLandscapeLeft ||isLandscapeRight) && imageSize.height > imageSize.width) {
    needsRotation = YES;
    CGFloat temp = imageSize.width;
    imageSize.width = imageSize.height;
    imageSize.height = temp;
  }
  
  UIGraphicsBeginImageContextWithOptions(imageSize, YES, 0);
  
  CGContextRef context = UIGraphicsGetCurrentContext();
  
  // Iterate over every window from back to front
  //NSInteger count = 0;
  for (UIWindow *window in [[UIApplication sharedApplication] windows])  {
    if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen]) {
      // -renderInContext: renders in the coordinate space of the layer,
      // so we must first apply the layer's geometry to the graphics context
      CGContextSaveGState(context);
      
      // Center the context around the window's anchor point
      CGContextTranslateCTM(context, [window center].x, [window center].y);
      
      // Apply the window's transform about the anchor point
      CGContextConcatCTM(context, [window transform]);
      
      // Offset by the portion of the bounds left of and above the anchor point
      CGContextTranslateCTM(context,
                            -[window bounds].size.width * [[window layer] anchorPoint].x,
                            -[window bounds].size.height * [[window layer] anchorPoint].y);
      
      if (needsRotation) {
        if (isLandscapeLeft) {
          CGContextConcatCTM(context, CGAffineTransformRotate(CGAffineTransformMakeTranslation( imageSize.width, 0), M_PI / 2.0));
        } else if (isLandscapeRight) {
          CGContextConcatCTM(context, CGAffineTransformRotate(CGAffineTransformMakeTranslation( 0, imageSize.height), 3 * M_PI / 2.0));
        }
      } else if (isUpsideDown) {
        CGContextConcatCTM(context, CGAffineTransformRotate(CGAffineTransformMakeTranslation( imageSize.width, imageSize.height), M_PI));
      }
      
      if ([window respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
        [window drawViewHierarchyInRect:window.bounds afterScreenUpdates:NO];
      } else {
        // Render the layer hierarchy to the current context
        [[window layer] renderInContext:context];
      }
      
      // Restore the context
      CGContextRestoreGState(context);
    }
  }
  
  // Retrieve the screenshot image
  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  
  UIGraphicsEndImageContext();
  
  return image;
}

#endif