import SwiftUI

struct Habit: Identifiable {
    let id = Int.random(in: 0...99999)
    let name: String
    let icon: String
    var streak: Int
    var done: Bool
}

struct HabitRingView: View {
    @State private var habits: [Habit] = [
        Habit(name: "Morning stretch", icon: "figure.cooldown", streak: 14, done: true),
        Habit(name: "Read 20 pages", icon: "book", streak: 9, done: false),
        Habit(name: "Deep work block", icon: "target", streak: 21, done: false),
        Habit(name: "Walk outside", icon: "figure.walk", streak: 5, done: false),
        Habit(name: "No screens after 10", icon: "moon", streak: 3, done: false)
    ]

    private var completed: Int { habits.filter(\.done).count }
    private var progress: Double { habits.isEmpty ? 0 : Double(completed) / Double(habits.count) }

    var body: some View {
        ZStack {
            Color(red: 0.04, green: 0.04, blue: 0.06).ignoresSafeArea()
            ScrollView {
                VStack(alignment: .leading, spacing: 16) {
                    Text("TUESDAY, 14 MAY")
                        .font(.caption).bold().foregroundColor(Color(red: 0.49, green: 0.36, blue: 1))
                    Text("Today").font(.system(size: 34, weight: .heavy)).foregroundColor(.white)

                    ZStack {
                        Circle().stroke(Color.white.opacity(0.08), lineWidth: 9).frame(width: 150, height: 150)
                        Circle()
                            .trim(from: 0, to: progress)
                            .stroke(Color(red: 0.49, green: 0.36, blue: 1), style: StrokeStyle(lineWidth: 9, lineCap: .round))
                            .rotationEffect(.degrees(-90))
                            .frame(width: 150, height: 150)
                            .animation(.easeInOut, value: progress)
                        VStack {
                            Text("\(Int(progress * 100))%").font(.system(size: 36, weight: .heavy)).foregroundColor(.white)
                            Text("\(completed) of \(habits.count)").font(.footnote).foregroundColor(.gray)
                        }
                    }
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 20)

                    ForEach($habits) { $habit in
                        Button {
                            habit.done.toggle()
                            habit.streak += habit.done ? 1 : -1
                        } label: {
                            HStack(spacing: 14) {
                                Image(systemName: habit.icon)
                                    .font(.title3).frame(width: 46, height: 46)
                                    .background(Color.white.opacity(0.06)).cornerRadius(13)
                                    .foregroundColor(.white)
                                VStack(alignment: .leading, spacing: 3) {
                                    Text(habit.name).fontWeight(.semibold)
                                        .strikethrough(habit.done)
                                        .foregroundColor(habit.done ? .gray : .white)
                                    Text("🔥 \(habit.streak) days").font(.footnote).foregroundColor(.gray)
                                }
                                Spacer()
                                Image(systemName: habit.done ? "checkmark.circle.fill" : "circle")
                                    .foregroundColor(habit.done ? Color(red: 0.49, green: 0.36, blue: 1) : .gray)
                                    .font(.title2)
                            }
                            .padding(14)
                            .background(Color.white.opacity(0.04)).cornerRadius(18)
                        }
                    }
                }
                .padding(22)
            }
        }
    }
}

#Preview { HabitRingView() }