import SwiftUI

struct DashboardView: View {
    @EnvironmentObject var authManager: AuthManager
    @State private var tasks: [PulseTask] = []
    @State private var habits: [Habit] = []
    @State private var readiness: ReadinessResponse?
    @State private var isLoading = true

    var greeting: String {
        let h = Calendar.current.component(.hour, from: Date())
        switch h {
        case 5..<12: return "Доброе утро"
        case 12..<17: return "Добрый день"
        case 17..<22: return "Добрый вечер"
        default: return "Доброй ночи"
        }
    }

    var pendingTasks: [PulseTask] { tasks.filter { !$0.completed } }
    var completedHabitsToday: Int { habits.filter { $0.completedToday == true }.count }

    var body: some View {
        ZStack {
            Color(hex: "0a0a1a").ignoresSafeArea()
            ScrollView {
                VStack(spacing: 20) {
                    // Header
                    HStack {
                        VStack(alignment: .leading, spacing: 4) {
                            Text(greeting + ", " + authManager.userName + "!")
                                .font(.title2.bold()).foregroundColor(.white)
                            Text(Date(), style: .date)
                                .font(.subheadline).foregroundColor(Color(hex: "8888aa"))
                        }
                        Spacer()

                        // Logout
                        Button {
                            UIImpactFeedbackGenerator(style: .light).impactOccurred()
                            authManager.logout()
                        } label: {
                            ZStack {
                                Circle()
                                    .fill(Color(hex: "1a1a3e"))
                                    .frame(width: 42, height: 42)
                                Image(systemName: "rectangle.portrait.and.arrow.right")
                                    .font(.system(size: 14, weight: .medium))
                                    .foregroundColor(Color(hex: "8888aa"))
                            }
                        }
                    }
                    .padding(.horizontal)
                    .padding(.top)

                    if isLoading {
                        ProgressView().tint(Color(hex: "00d4aa")).padding(.top, 40)
                    } else {
                        // Readiness Score mini card
                        if let r = readiness {
                            ReadinessMiniCard(readiness: r)
                        }

                        // Stats row
                        HStack(spacing: 12) {
                            StatCard(icon: "checkmark.circle.fill", value: "\(pendingTasks.count)", label: "Задач", color: "00d4aa")
                            StatCard(icon: "flame.fill", value: "\(completedHabitsToday)/\(habits.count)", label: "Привычек", color: "ffa502")
                            if let r = readiness {
                                StatCard(icon: "heart.fill", value: "\(r.score)", label: "Готовность", color: r.score >= 80 ? "00d4aa" : r.score >= 60 ? "ffa502" : "ff4757")
                            }
                        }
                        .padding(.horizontal)

                        // Today's tasks
                        if !pendingTasks.isEmpty {
                            VStack(alignment: .leading, spacing: 12) {
                                Text("Задачи на сегодня").font(.headline).foregroundColor(.white).padding(.horizontal)
                                ForEach(pendingTasks.prefix(3)) { task in
                                    TaskRowView(task: task) {
                                        await completeTask(task)
                                    }
                                }
                            }
                        }

                        // Habits progress
                        if !habits.isEmpty {
                            VStack(alignment: .leading, spacing: 12) {
                                Text("Привычки сегодня").font(.headline).foregroundColor(.white).padding(.horizontal)
                                ForEach(habits.prefix(4)) { habit in
                                    HabitRowView(habit: habit) {
                                        await logHabit(habit)
                                    }
                                }
                            }
                        }
                    }
                    Spacer(minLength: 20)
                }
            }
            .refreshable { await loadData(refresh: true) }
        }
        .task { await loadData() }
    }

    func loadData(refresh: Bool = false) async {
        if !refresh { isLoading = true }
        async let t = APIService.shared.getTodayTasks(token: authManager.token)
        async let h = APIService.shared.getHabits(token: authManager.token)
        async let r = HealthAPIService.shared.getReadiness(apiKey: authManager.healthApiKey)
        tasks = (try? await t) ?? []
        habits = (try? await h) ?? []
        readiness = try? await r
        isLoading = false
    }

    func completeTask(_ task: PulseTask) async {
        try? await APIService.shared.completeTask(token: authManager.token, id: task.id)
        await loadData()
    }

    func logHabit(_ habit: Habit) async {
        try? await APIService.shared.logHabit(token: authManager.token, id: habit.id)
        await loadData()
    }
}

// MARK: - StatCard

struct StatCard: View {
    let icon: String
    let value: String
    let label: String
    let color: String

    var body: some View {
        VStack(spacing: 6) {
            Image(systemName: icon).foregroundColor(Color(hex: color)).font(.title3)
            Text(value).font(.headline.bold()).foregroundColor(.white)
            Text(label).font(.caption).foregroundColor(Color(hex: "8888aa"))
        }
        .frame(maxWidth: .infinity)
        .padding(12)
        .background(RoundedRectangle(cornerRadius: 16).fill(Color.white.opacity(0.05)))
    }
}

// MARK: - ReadinessMiniCard

struct ReadinessMiniCard: View {
    let readiness: ReadinessResponse

    var statusColor: Color {
        readiness.score >= 80 ? Color(hex: "00d4aa") :
        readiness.score >= 60 ? Color(hex: "ffa502") :
        Color(hex: "ff4757")
    }

    var body: some View {
        HStack(spacing: 16) {
            ZStack {
                Circle().stroke(Color.white.opacity(0.1), lineWidth: 6).frame(width: 60, height: 60)
                Circle().trim(from: 0, to: CGFloat(readiness.score) / 100)
                    .stroke(statusColor, style: StrokeStyle(lineWidth: 6, lineCap: .round))
                    .frame(width: 60, height: 60).rotationEffect(.degrees(-90))
                Text("\(readiness.score)").font(.headline.bold()).foregroundColor(statusColor)
            }
            VStack(alignment: .leading, spacing: 4) {
                Text("Готовность").font(.subheadline).foregroundColor(Color(hex: "8888aa"))
                Text(readiness.recommendation).font(.callout).foregroundColor(.white).lineLimit(2)
            }
            Spacer()
        }
        .padding(16)
        .background(RoundedRectangle(cornerRadius: 16).fill(Color.white.opacity(0.05)))
        .padding(.horizontal)
    }
}