CountdownView.swift

import Combine
import SwiftUI

struct CountdownView: View {
    @State private var countdown: Int = 15 * 60
    @State private var displayedTime = "15:00"
    @State private var countdownTimer: AnyCancellable?
    
    @State private var isShowingLaurels = false
    @State private var isShowingExpiry = false
    @State private var isShowingCountdown = false
    
    var body: some View {
        HStack {
            LaurelIcon(isShowing: isShowingLaurels, direction: .leading)
            
            VStack {
                Text("Expires in")
                    .bold()
                    .opacity(0.6)
                    .opacity(isShowingExpiry ? 0.6 : 0)
                    .offset(y: isShowingExpiry ? 0 : 50)
                    .animation(.spring(response: 0.4, dampingFraction: 0.4, blendDuration: 1.0), value: isShowingExpiry)
                
                Text(displayedTime)
                    .fontDesign(.rounded)
                    .font(.system(size: 60))
                    .bold()
                    .monospacedDigit()
                    .contentTransition(.numericText(countsDown: true))
                    .opacity(isShowingCountdown ? 1 : 0)
                    .blur(radius: isShowingCountdown ? 0 : 10)
                    .scaleEffect(isShowingCountdown ? 1 : 1.2)
                    .animation(.spring(response: 0.4, dampingFraction: 0.4, blendDuration: 1.0), value: isShowingCountdown)
            }
            
            LaurelIcon(isShowing: isShowingLaurels, direction: .trailing)
        }
        .onAppear {
            animateEntrance()
            startCountdown()
        }
        .onDisappear {
            resetAnimations()
            stopCountdown()
        }
        .padding()
    }
}

extension CountdownView {
    private func animateEntrance() {
        Task {
            isShowingCountdown = false
            isShowingLaurels = false
            isShowingExpiry = false
            
            try? await Task.sleep(nanoseconds: 100_000_000)
            withAnimation { isShowingCountdown = true }
            
            try? await Task.sleep(nanoseconds: 100_000_000)
            withAnimation { isShowingLaurels = true }
            
            try? await Task.sleep(nanoseconds: 100_000_000)
            withAnimation { isShowingExpiry = true }
        }
    }
    
    private func resetAnimations() {
        isShowingCountdown = false
        isShowingLaurels = false
        isShowingExpiry = false
    }
    
    private func startCountdown() {
        stopCountdown()
        
        countdownTimer = Timer.publish(every: 1, on: .main, in: .common)
            .autoconnect()
            .sink { _ in
                if countdown > 0 {
                    countdown -= 1
                    updateDisplayedTime()
                } else {
                    stopCountdown()
                }
            }
    }
    
    private func stopCountdown() {
        countdownTimer?.cancel()
        countdownTimer = nil
    }
    
    private func updateDisplayedTime() {
        let minutes = countdown / 60
        let seconds = countdown % 60
        let newTime = String(format: "%02d:%02d", minutes, seconds)
        
        withAnimation {
            displayedTime = newTime
        }
    }
}

struct LaurelIcon: View {
    var isShowing: Bool
    var direction: Direction
    
    enum Direction {
        case leading, trailing
    }
    
    var body: some View {
        Image(systemName: direction == .leading ? "laurel.leading" : "laurel.trailing")
            .font(.system(size: 50))
            .opacity(isShowing ? 0.6 : 0)
            .offset(x: isShowing ? 0 : (direction == .leading ? 50 : -50))
            .animation(.spring(response: 0.4, dampingFraction: 0.5), value: isShowing)
    }
}

#Preview("Countdown") {
    CountdownView()
}