deltachat-ios/deltachat-ios/Extensions/UIImage+Extension.swift

import UIKit

extension UIImage {
    func imageResize(sizeChange: CGSize) -> UIImage {
        let hasAlpha = true
        let scale: CGFloat = 0.0 // Use scale factor of main screen

        UIGraphicsBeginImageContextWithOptions(sizeChange, !hasAlpha, scale)
        draw(in: CGRect(origin: CGPoint.zero, size: sizeChange))

        let scaledImage = UIGraphicsGetImageFromCurrentImageContext()
        return scaledImage!
    }

    public convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
        let rect = CGRect(origin: .zero, size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        color.setFill()
        UIRectFill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        guard let cgImage = image?.cgImage else { return nil }
        self.init(cgImage: cgImage)
    }

    func resizeImage(targetSize: CGSize) -> UIImage? {
        let size = self.size

        let widthRatio  = targetSize.width  / size.width
        let heightRatio = targetSize.height / size.height

        var newSize: CGSize
        if widthRatio > heightRatio {
            newSize = CGSize(width: size.width * heightRatio, height: size.height * heightRatio)
        } else {
            newSize = CGSize(width: size.width * widthRatio, height: size.height *      widthRatio)
        }

        let rect = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)

        UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
        draw(in: rect)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return newImage
    }

    func dcCompress(toMax target: Float = 1280) -> UIImage? {
        return resize(toMax: target)
    }

    func imageSizeInPixel() -> CGSize {
        let heightInPoints = size.height
        let heightInPixels = heightInPoints * scale
        let widthInPoints = size.width
        let widthInPixels = widthInPoints * scale
        return CGSize(width: widthInPixels, height: heightInPixels)
    }

    // source: https://stackoverflow.com/questions/29137488/how-do-i-resize-the-uiimage-to-reduce-upload-image-size // slightly changed
    func resize(toMax: Float) -> UIImage? {
        var actualHeight = Float(size.height)
        var actualWidth = Float(size.width)
        let maxHeight: Float = toMax
        let maxWidth: Float = toMax
        var imgRatio: Float = actualWidth / actualHeight
        let maxRatio: Float = maxWidth / maxHeight
        let compressionQuality: Float = 0.5
        //50 percent compression
        if actualHeight > maxHeight || actualWidth > maxWidth {
            if imgRatio < maxRatio {
                //adjust width according to maxHeight
                imgRatio = maxHeight / actualHeight
                actualWidth = imgRatio * actualWidth
                actualHeight = maxHeight
            } else if imgRatio > maxRatio {
                //adjust height according to maxWidth
                imgRatio = maxWidth / actualWidth
                actualHeight = imgRatio * actualHeight
                actualWidth = maxWidth
            } else {
                actualHeight = maxHeight
                actualWidth = maxWidth
            }
        }

        let rect = CGRect(x: 0.0, y: 0.0, width: CGFloat(actualWidth), height: CGFloat(actualHeight))
        UIGraphicsBeginImageContext(rect.size)
        draw(in: rect)
        let img = UIGraphicsGetImageFromCurrentImageContext()
        let imageData = img?.jpegData(compressionQuality: CGFloat(compressionQuality))
        UIGraphicsEndImageContext()
        return UIImage(data: imageData!)
    }

    public class func messageKitImageWith(type: ImageType) -> UIImage? {
        let assetBundle = Bundle.messageKitAssetBundle()
        let imagePath = assetBundle.path(forResource: type.rawValue, ofType: "png", inDirectory: "Images")
        let image = UIImage(contentsOfFile: imagePath ?? "")
        return image
    }

}

public enum ImageType: String {
    case play
    case pause
    case disclouser
}