import UIKit

extension UIColor {

    /// Creates a color based on a hexString. If the string is not a valid hexColor it return nil
    /// Example of colors: #FF0000, #00FF0000
    ///
    convenience init?(hexString: String) {

        let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
        var int = UInt32()
        if !Scanner(string: hex).scanHexInt32(&int) {
            return nil
        }
        let a, r, g, b: UInt32
        switch hex.count {
        case 3: // RGB (12-bit)
            (a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
        case 8: // ARGB (32-bit)
            (a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
        default:
            return nil
        }
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
    }

}