⚓️:: [#22] Stopwatch 추가

Sources/MindGymKit /Stopwatch.swift

@@ -0,0 +1,66 @@
+//
+//  File.swift
+//  
+//
+//  Created by 박준하 on 12/28/23.
+//
+
+import UIKit
+import RxSwift
+
+// MARK: - Stopwatch
+public protocol TimerControl {
+    func start()
+    func stop()
+    func reset()
+    func record()
+}
+
+public class Stopwatch: NSObject, TimerControl {
+    private var counter: Double = 0.0
+    private var timer: Timer?
+    private var lapTimes: [Double] = []
+    private let timeSubject = PublishSubject<String>()
+    private let recordSubject = PublishSubject<[String]>()
+
+    public var timeUpdate: Observable<String> {
+        return timeSubject.asObservable()
+    }
+
+    public var recordUpdate: Observable<[String]> {
+        return recordSubject.asObservable()
+    }
+
+    public func start() {
+        timer = Timer.scheduledTimer(withTimeInterval: 0.035, repeats: true) { [weak self] _ in
+            guard let self = self else { return }
+            self.counter += 0.035
+            let timeString = self.timeString(from: self.counter)
+            self.timeSubject.onNext(timeString)
+        }
+    }
+
+    public func stop() {
+        timer?.invalidate()
+        timer = nil
+    }
+
+    public func reset() {
+        counter = 0
+        lapTimes.removeAll()
+    }
+
+    public func record() {
+        lapTimes.append(counter)
+        let lapTimesString = lapTimes.map { timeString(from: $0) }
+        recordSubject.onNext(lapTimesString)
+    }
+
+    private func timeString(from counter: Double) -> String {
+        let minutes: String = String(format: "%02d", Int(counter / 60))
+        let seconds: String = String(format: "%02d", Int(counter.truncatingRemainder(dividingBy: 60)))
+        let milliseconds: String = String(format: "%02d", Int((counter * 100).truncatingRemainder(dividingBy: 100)))
+        return "\(minutes):\(seconds).\(milliseconds)"
+    }
+}
+