//
//  ContentView.swift
//  RGBullsEye
//
//  Created by Heredia, Daniel on 11/21/19.
//  Copyright © 2019 Heredia, Daniel. All rights reserved.
//

import SwiftUI

struct ContentView: View {

    let rTarget = Double.random(in: 0..<1)
    let gTarget = Double.random(in: 0..<1)
    let bTarget = Double.random(in: 0..<1)
    @State var rGuess: Double
    @State var gGuess: Double
    @State var bGuess: Double
    @State var showAlert = false

    var body: some View {
        VStack {
            HStack {
                // Target color block
                VStack {
                    Rectangle()
                    .foregroundColor(Color(red: rTarget, green: gTarget, blue: bTarget, opacity: 1.0))
                    Text("Match this color")
                }
                // Guess color block
                VStack {
                    Rectangle()
                    .foregroundColor(Color(red: rGuess, green: gGuess, blue: bGuess, opacity: 1.0))
                    HStack {
                        Text("R: \(Int(rGuess * 255.0))")
                        Text("G: \(Int(gGuess * 255.0))")
                        Text("B: \(Int(bGuess * 255.0))")
                    }
                }
            }
            // Sliders
            VStack {
                // Hit button
                Button(action: {
                    self.showAlert = true
                }) {
                    Text("Hit me")
                }
                .alert(isPresented: $showAlert) {
                    Alert(title: Text("Your Score"), message: Text("\(computeScore())"))
                }
                ColorSlider(value: $rGuess, textColor: .red)
                .padding()
                ColorSlider(value: $gGuess, textColor: .green)
                .padding()
                ColorSlider(value: $bGuess, textColor: .blue)
                .padding()
            }
        }
    }



    struct ColorSlider: View {
        @Binding var value: Double
        var textColor: Color

        var body: some View {
            HStack {
                Text("0")
                    .foregroundColor(.red)
                Slider(value: $value)
                Text("255")
                    .foregroundColor(textColor)
            }
        }
    }
}

// MARK: - Utils
extension ContentView {

    func computeScore() -> Int {
      let rDiff = rGuess - rTarget
      let gDiff = gGuess - gTarget
      let bDiff = bGuess - bTarget
      let diff = sqrt(rDiff * rDiff + gDiff * gDiff + bDiff * bDiff)
      return Int((1.0 - diff) * 100.0 + 0.5)
    }



}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView(rGuess: 0.5, gGuess: 0.5, bGuess: 0.5)
    }
}