SwiftUI Color Extension

Color+Extension.swift

//
//  Color+Extension.swift
//  Helpers pack with:
//  
//  1 - encode/decode RGBA
//  2 - accessibleFontColor depends on background color
//  3 - isLightColor - color lightness detection
//
//  Created by Alexo on 19.12.2020.
//

import SwiftUI

extension Color: Codable {
	private struct Components {
		let red: Double
		let green: Double
		let blue: Double
		let alpha: Double
	}
	
	private enum CodingKeys: String, CodingKey {
		case red
		case green
		case blue
		case alpha
	}
	
	/// A new random color.
	static var random: Color {
		let red = Double.random(in: 0...1)
		let green = Double.random(in: 0...1)
		let blue = Double.random(in: 0...1)
		return Color(.sRGB, red: red, green: green, blue: blue, opacity: 1)
	}
	
	private var components: Components {
		var red: CGFloat = 0
		var green: CGFloat = 0
		var blue: CGFloat = 0
		var alpha: CGFloat = 0
		UIColor(self).getRed(&red, green: &green, blue: &blue, alpha: &alpha)
		return Components(red: Double(red),
								green: Double(green),
								blue: Double(blue),
								alpha: Double(alpha))
	}
	
	public init(from decoder: Decoder) throws {
		let container = try decoder.container(keyedBy: CodingKeys.self)
		let red = try container.decode(Double.self, forKey: .red)
		let green = try container.decode(Double.self, forKey: .green)
		let blue = try container.decode(Double.self, forKey: .blue)
		let alpha = try container.decode(Double.self, forKey: .alpha)
		self.init(Components(red: red, green: green, blue: blue, alpha: alpha))
	}
	
	private init(_ components: Components) {
		self.init(.sRGB, red: components.red, green: components.green, blue: components.blue, opacity: components.alpha)
	}
	
	public func encode(to encoder: Encoder) throws {
		var container = encoder.container(keyedBy: CodingKeys.self)
		let components = self.components
		try container.encode(components.red, forKey: .red)
		try container.encode(components.green, forKey: .green)
		try container.encode(components.blue, forKey: .blue)
		try container.encode(components.alpha, forKey: .alpha)
	}
	
	// MARK: - font colors
	/// This color is either black or white, whichever is more accessible when viewed against the scrum color.
	var accessibleFontColor: Color {
		var red: CGFloat = 0
		var green: CGFloat = 0
		var blue: CGFloat = 0
		UIColor(self).getRed(&red, green: &green, blue: &blue, alpha: nil)
		return isLightColor(red: red, green: green, blue: blue) ? .black : .white
	}
	
	private func isLightColor(red: CGFloat, green: CGFloat, blue: CGFloat) -> Bool {
		let lightRed = red > 0.65
		let lightGreen = green > 0.65
		let lightBlue = blue > 0.65
		
		let lightness = [lightRed, lightGreen, lightBlue].reduce(0) { $1 ? $0 + 1 : $0 }
		return lightness >= 2
	}
}