import UIKit

let appIconApple = generateAppleIcon()
let appIconUnknown = generateUnknownIcon()

func generateAppleIcon() -> UIImage? {
	let rect = CGRect(x: 0, y: 0, width: 30, height: 30)
	UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
	
//	#colorLiteral(red: 0.5843137503, green: 0.8235294223, blue: 0.4196078479, alpha: 1).setFill()
//	UIBezierPath(roundedRect: rect, cornerRadius: 0).fill()
//	print("drawing")
	let fs = 36 as CGFloat
	let hFont = UIFont.systemFont(ofSize: fs)
	var attrib = [
		NSAttributedString.Key.font: hFont,
		NSAttributedString.Key.foregroundColor: UIColor.gray
	]
	
	let str = "" as NSString
	let actualHeight = str.size(withAttributes: attrib).height
	attrib[NSAttributedString.Key.font] = hFont.withSize(fs * fs / actualHeight)
	
	let strW = str.size(withAttributes: attrib).width
	str.draw(at: CGPoint(x: (rect.size.width - strW) / 2.0, y: -3), withAttributes: attrib)
	
	let img = UIGraphicsGetImageFromCurrentImageContext()
	UIGraphicsEndImageContext()
	return img
}

func generateUnknownIcon() -> UIImage? {
	let rect = CGRect(x: 0, y: 0, width: 30, height: 30)
	UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
	
	let context = UIGraphicsGetCurrentContext()!
	let lineWidth: CGFloat = 0.5
	let corner: CGFloat = 6.75
	let c = corner / CGFloat.pi + lineWidth/2
	let sz: CGFloat = rect.height
	let m = sz / 2
	let r1 = 0.2 * sz, r2 = sqrt(2 * r1 * r1)
	
	// diagonal
	context.lineFromTo(x1: c, y1: c, x2: sz-c, y2: sz-c)
	context.lineFromTo(x1: c, y1: sz-c, x2: sz-c, y2: c)
	// horizontal
	context.lineFromTo(x1: 0, y1: m, x2: sz, y2: m)
	context.lineFromTo(x1: 0, y1: m + r1, x2: sz, y2: m + r1)
	context.lineFromTo(x1: 0, y1: m - r1, x2: sz, y2: m - r1)
	// vertical
	context.lineFromTo(x1: m, y1: 0, x2: m, y2: sz)
	context.lineFromTo(x1: m + r1, y1: 0, x2: m + r1, y2: sz)
	context.lineFromTo(x1: m - r1, y1: 0, x2: m - r1, y2: sz)
	// circles
	context.addEllipse(in: CGRect(x: m - r1, y: m - r1, width: 2*r1, height: 2*r1))
	context.addEllipse(in: CGRect(x: m - r2, y: m - r2, width: 2*r2, height: 2*r2))
	let r3 = CGRect(x: c, y: c, width: sz - 2*c, height: sz - 2*c)
	context.addEllipse(in: r3)
	context.addRect(r3)
	
	UIColor.clear.setFill()
	UIColor.gray.setStroke()
	let rounded = UIBezierPath(roundedRect: rect.insetBy(dx: lineWidth/2, dy: lineWidth/2), cornerRadius: corner)
	rounded.lineWidth = lineWidth
	rounded.stroke()
	
	let img = UIGraphicsGetImageFromCurrentImageContext()
	UIGraphicsEndImageContext()
	return img
}

extension CGContext {
	func lineFromTo(x1: CGFloat, y1: CGFloat, x2: CGFloat, y2: CGFloat) {
		self.move(to: CGPoint(x: x1, y: y1))
		self.addLine(to: CGPoint(x: x2, y: y2))
	}
}