ContentView.swift

import SwiftUI

struct ContentView: View {
    @State var babblingState = false // Bool to show/hide progress indicators
    @State var userInput = "" // binding var to set textfield to show user input
    @State var timeDisplay = "Time"
    @State var iterationsDisplay = "Iterations"
    @State var output = ""
    @State var result = []
    @State var babbleQueue: DispatchWorkItem?
    @State var babbleProgress = 0.1
    @State var babbleTotal = 0.2 // placeholders until proper values are passed

    var body: some View {
        VStack {
            ZStack {
                VStack { // Progress Indicators
                    ForEach(0..<2) { i in
                        Spacer()
                    }
                    if babblingState {
                        ProgressView("Babbling")
                            .padding()
                        ProgressView(value: babbleProgress, total: babbleTotal)
                            .padding()
                    } else  {
                        ProgressView("Babbling")
                            .padding()
                            .hidden()
                        ProgressView(value: 50, total: 100)
                            .padding()
                            .hidden()
                    }
                    ForEach(0..<1) { i in
                        Spacer()
                    }
                }
                VStack { // Time/Iterations
                    ForEach(0..<1) { i in
                        Spacer()
                    }
                    Text(timeDisplay)
                        .font(.title)
                        .padding()
                    Text(iterationsDisplay)
                        .font(.subheadline)
                        .padding(.leading)
                        .padding(.trailing)
                    ForEach(0..<6) { i in
                        Spacer()
                    }
                }
                VStack { // Babble/Cancel Button
                    ForEach(0..<2) { i in
                        Spacer()
                    }
                    if babblingState {
                        Button(action: {
                            babblingState = false;
                            print("Cancelling");
                            babbleQueue?.cancel();
                            print("babbleQueue cancelled?")
                            
                        }) {
                            Text("Cancel")
                                .foregroundColor(.red)
                        }
                    } else {
                        Button(action: {
                            babblingState = true;
                            babbleQueue = DispatchWorkItem {
                                print("babbleIt dispatching")
                                result = babbleIt(input: userInput)
                                output = result[2] as! String
                                timeDisplay = result[1] as! String
                                iterationsDisplay = result[0] as! String
                                babblingState = false
                            }
                            DispatchQueue.global(qos: .utility).async(execute: babbleQueue!)
                            print("Executing babbleQueue")
                            
                        }) {
                            Text("Babble")
                                .foregroundColor(.green)
                        }
                    }
                    ForEach(0..<3) { i in
                        Spacer()
                    }
                }
                VStack { // Text Entry
                    TextField("Babble Here", text: $userInput)
                        .font(.largeTitle)
                        .multilineTextAlignment(.center)
                        .padding()
                }
                VStack { // History
                    ForEach(0..<12) { i in
                        Spacer()
                    }
                    Divider()
                        .padding()
                    ForEach(0..<1) { i in
                        Spacer()
                    }
                    Text("View History")
                        .padding(.top)
                    ForEach(0..<1) { i in
                        Spacer()
                    }
                }
            }
        }
    }
    
    func babbleIt(input: String) ->  Array<String> { // Func takes a String input and returns an array of strings
        print("babbleIt beginning")
        let startTime = Double(Date.timeIntervalSinceReferenceDate) // sets start time to the current time since refernceDate
        var finishTime = 0.0 // sets finish time to 0.0 as placeholder
        let sanitizedInput = input.lowercased()
        let charArray = sanitizedInput.map( {String($0) }) // transforms input string into an array of characters corresponding to each letter of the string
        var asciiArray: Array<UInt8> = [] // inits an empty array of ints
        for i in charArray { // loops for each item in charArray
            asciiArray.append(Character(i).asciiValue!) // takes the ascii numerical value of each character, and adds it to the ascii array
        }
        var babbleComplete = false // state var for determining when to stop iterating
        var positionInBabble = 0 // state var for keeping track of where in the array the current loop is
        var iterations = 0 // state var to hold how many times the loop resets
        while !babbleComplete { // loops while babbleComplete is false
            iterations += 1 // adds one to iteration value
            //usleep(500)
            babbleProgress = Double(positionInBabble)
            iterationsDisplay = String(iterations)
            let num = Int.random(in: 96...122) // generates random int in the ascii range of a-z/A-Z
            if UInt8(num) == asciiArray[positionInBabble] { // if the generated number matches the value of the current array position, move up one object in the array
                positionInBabble += 1
                if positionInBabble == asciiArray.count { // if the position in the array is the final position, set the complete state to true, ending the loop. Otherwise, resets loop
                    babbleComplete = true
                    finishTime = Double(Date.timeIntervalSinceReferenceDate) // sets finish time to current time since referenceDate
                }
            } else {
                positionInBabble = 0
            }
        }
        let elapsedTime = (finishTime - startTime) // declares elapsedTime as the difference between the finish and starting dates, to establish time elapsed
        print("babbleIt completed")
        return [String(iterations), String(elapsedTime), input]
    }
}