Added a timer view

Nextcloud Cookbook iOS Client/Views/TimerView.swift

@@ -0,0 +1,127 @@
+//
+//  TimerView.swift
+//  Nextcloud Cookbook iOS Client
+//
+//  Created by Vincent Meilinger on 11.01.24.
+//
+
+import Foundation
+import SwiftUI
+import Combine
+
+
+struct TimerView: View {
+    @ObservedObject var timer: RecipeTimer
+    
+    var body: some View {
+        HStack {
+            Gauge(value: timer.timeTotal - timer.timeElapsed, in: 0...timer.timeTotal) {
+                Text("Cooking time")
+            } currentValueLabel: {
+                Button {
+                    if timer.isRunning {
+                        timer.pause()
+                    } else {
+                        timer.start()
+                    }
+                } label: {
+                    if timer.isRunning {
+                        Image(systemName: "pause.fill")
+                            .foregroundStyle(.blue)
+                    } else {
+                        Image(systemName: "play.fill")
+                            .foregroundStyle(.blue)
+                    }
+                }
+            }
+            .gaugeStyle(.accessoryCircularCapacity)
+            .animation(.easeInOut, value: timer.timeElapsed)
+            .tint(.white)
+            
+            VStack(alignment: .leading) {
+                HStack {
+                    Text("Cooking time")
+                        .padding(.horizontal)
+                    Button {
+                        timer.cancel()
+                    } label: {
+                        Image(systemName: "xmark.circle.fill")
+                    }
+                }
+                Text("\(Int(timer.timeTotal - timer.timeElapsed))")
+                    .padding(.horizontal)
+            }
+        }
+        .bold()
+        .padding()
+        .background {
+            RoundedRectangle(cornerRadius: 20)
+                .foregroundStyle(.ultraThickMaterial)
+        }
+    }
+}
+
+
+
+class RecipeTimer: ObservableObject {
+    var timeTotal: Double
+    private var startDate: Date?
+    private var pauseDate: Date?
+    @Published var timeElapsed: Double = 0
+    @Published var isRunning: Bool = false
+    private var timer: Timer.TimerPublisher?
+    private var timerCancellable: Cancellable?
+
+    init(timeTotal: Double) {
+        self.timeTotal = timeTotal
+    }
+    
+    func start() {
+        self.isRunning = true
+        if startDate == nil {
+            startDate = Date()
+        } else if let pauseDate = pauseDate {
+            // Adjust start date based on the pause duration
+            let pauseDuration = Date().timeIntervalSince(pauseDate)
+            startDate = startDate?.addingTimeInterval(pauseDuration)
+        }
+
+        self.timer = Timer.publish(every: 1, on: .main, in: .common)
+        self.timerCancellable = self.timer?.autoconnect().sink { [weak self] _ in
+            DispatchQueue.main.async {
+                if let self = self, let startTime = self.startDate {
+                    let elapsed = Date().timeIntervalSince(startTime)
+                    if elapsed < self.timeTotal {
+                        self.timeElapsed = elapsed
+                    } else {
+                        self.timeElapsed = self.timeTotal
+                        self.pause()
+                    }
+                }
+            }
+        }
+    }
+    
+    func pause() {
+        self.isRunning = false
+        pauseDate = Date()
+        self.timerCancellable?.cancel()
+        self.timerCancellable = nil
+        self.timer = nil
+    }
+    
+    func resume() {
+        self.isRunning = true
+        start()
+    }
+    
+    func cancel() {
+        self.isRunning = false
+        self.timerCancellable?.cancel()
+        self.timerCancellable = nil
+        self.timer = nil
+        self.timeElapsed = 0
+        self.startDate = nil
+        self.pauseDate = nil
+    }
+}