ColourViewModel+Response.swift

private extension ColourViewModel {
  var url: URL { URL(string: "http://colormind.io/api/")! }
  
  var input: [Input] {
    let colour1: Input = .integerArray([Int(red1 * Response.max),
                                        Int(green1 * Response.max),
                                        Int(blue1 * Response.max)])
    let colour2: Input = .integerArray([Int(red2 * Response.max),
                                        Int(green2 * Response.max),
                                        Int(blue2 * Response.max)])
    return [colour1, .unknown, .unknown, .unknown, colour2]
  }
  
  var request: URLRequest {
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    let body = Request(input: input, model: "default")
    guard let data = try? JSONEncoder().encode(body) else {
      return request
    }
    request.httpBody = data
    return request
  }
  
  func getResponse() async -> Response {
    await withUnsafeContinuation { continuation in
      URLSession.shared.dataTask(with: request) { (data, response, error) in
        guard let data, let successfulResponse = try?
                JSONDecoder().decode(Response.self, from: data) else {
          fatalError("Data not found or Response couldn't be decoded")
        }
        continuation.resume(with: .success(successfulResponse))
      }.resume()
    }
  }
  
  struct Response: Codable {
    static var max: Double { Double(UInt8.max) }
    let result: [[Int]]
    func schemeColour(atIndex index: Int) -> Color? {
      guard result.indices.contains(index), result[index].count == 3 else {
        return nil
      }
      let array = result[index]
      return Color(red: Double(array[0]) / Self.max,
                   green: Double(array[1]) / Self.max,
                   blue: Double(array[2]) / Self.max)
    }
  }
}