//
//  ContentView.swift
//  TheSwiftUI
//
//  Created by Valerio De Rosa on 14.06.19.
//  Copyright © 2019 Incloud Engineering GmbH. All rights reserved.
//

import SwiftUI

struct ColorSlider : View {

    @Binding var value: Double
    var textColor: Color

    var body: some View {
        HStack {
            Text("0").color(textColor)
            Slider(value: $value, from: 0.0, through: 1.0)
            Text("255").color(textColor)
        }.padding()
    }
}

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


    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)
    }

    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))")
                    }
                }
            }

            Button(action: {
                self.showAlert = true
            }) {
                Text("Hit Me!")
            }.presentation($showAlert) {
                Alert(title: Text("Your Score"), message: Text("\(computeScore())"))
            }.padding()

            VStack {
                ColorSlider(value: $rGuess, textColor: .red)
                ColorSlider(value: $gGuess, textColor: .green)
                ColorSlider(value: $bGuess, textColor: .blue)
            }
        }
    }
}

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