import SwiftUI
import HealthKit

struct ContentView: View {
    @EnvironmentObject private var workout: WorkoutManager

    var body: some View {
        Group {
            if workout.isRunning {
                LiveWorkoutView()
            } else {
                ActivityPickerView()
            }
        }
        .task {
            // Déclenchement auto du mode test (validation simulateur) :
            // SIMCTL_CHILD_AUTOSIM=1 xcrun simctl launch …
            if ProcessInfo.processInfo.environment["AUTOSIM"] == "1" {
                workout.startSimulation()
            }
        }
    }
}

struct ActivityPickerView: View {
    @EnvironmentObject private var workout: WorkoutManager
    @State private var showRoutine = false
    @State private var showVma = false

    private struct Activity: Identifiable {
        let id = UUID()
        let label: String
        let symbol: String
        let type: HKWorkoutActivityType
        let location: HKWorkoutSessionLocationType
    }

    private let activities: [Activity] = [
        .init(label: "Course", symbol: "figure.run", type: .running, location: .outdoor),
        .init(label: "Vélo", symbol: "figure.outdoor.cycle", type: .cycling, location: .outdoor),
        .init(label: "Marche", symbol: "figure.walk", type: .walking, location: .outdoor),
        .init(label: "Renfo", symbol: "dumbbell", type: .traditionalStrengthTraining, location: .indoor)
    ]

    var body: some View {
        ScrollView {
            VStack(spacing: 8) {
                ForEach(activities) { activity in
                    Button {
                        Task {
                            await workout.startWorkout(activityType: activity.type,
                                                       locationType: activity.location)
                        }
                    } label: {
                        Label(activity.label, systemImage: activity.symbol)
                            .frame(maxWidth: .infinity, alignment: .leading)
                    }
                }
                Button {
                    showRoutine = true
                } label: {
                    Label("Routine du jour", systemImage: "figure.cooldown")
                        .frame(maxWidth: .infinity, alignment: .leading)
                }
                .tint(.cyan)

                Button {
                    showVma = true
                } label: {
                    Label("Test VMA", systemImage: "speedometer")
                        .frame(maxWidth: .infinity, alignment: .leading)
                }
                .tint(.orange)

                Button {
                    workout.startSimulation()
                } label: {
                    Label("Test (FC simulée)", systemImage: "waveform.path.ecg")
                        .frame(maxWidth: .infinity, alignment: .leading)
                }
                .tint(.gray)

                if let message = workout.statusMessage {
                    Text(message)
                        .font(.footnote)
                        .foregroundStyle(.secondary)
                }
            }
            .padding(.horizontal, 4)
        }
        .navigationTitle("Coach")
        .sheet(isPresented: $showRoutine) {
            RoutineView()
        }
        .sheet(isPresented: $showVma) {
            VmaTestView()
        }
    }
}

struct LiveWorkoutView: View {
    @EnvironmentObject private var workout: WorkoutManager
    @EnvironmentObject private var connectivity: ConnectivityManager

    var body: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 10) {
                HeartRateMetric(bpm: Int(workout.heartRate), zones: connectivity.zones)
                Metric(label: "Calories", value: "\(Int(workout.activeEnergyKcal))", unit: "kcal", color: .orange)
                Metric(label: "Distance",
                       value: String(format: "%.2f", workout.distanceMeters / 1000),
                       unit: "km", color: .blue)
                // km/h plutôt que l'allure min/km : l'app Exercice d'Apple ne
                // propose la vitesse qu'à vélo, jamais en course.
                Metric(label: "Vitesse",
                       value: workout.speedKmh > 0
                           ? String(format: "%.1f", workout.speedKmh) : "—",
                       unit: "km/h", color: .cyan)
                Metric(label: "Durée", value: Self.timeString(workout.elapsedSec), unit: "", color: .green)

                HStack(spacing: 4) {
                    Image(systemName: connectivity.isReachable
                          ? "iphone.radiowaves.left.and.right" : "iphone.slash")
                        .foregroundStyle(connectivity.isReachable ? .green : .secondary)
                    Text(connectivity.isReachable ? "iPhone connecté" : "iPhone hors de portée")
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                }

                // Pause/reprise : la Live Activity de l'iPhone pilote les mêmes
                // appels, l'état affiché ici doit donc suivre `isPaused` et non
                // un état local au bouton.
                Button {
                    workout.isPaused ? workout.resume() : workout.pause()
                } label: {
                    Label(workout.isPaused ? "Reprendre" : "Pause",
                          systemImage: workout.isPaused ? "play.fill" : "pause.fill")
                        .frame(maxWidth: .infinity)
                }
                .tint(workout.isPaused ? .green : .yellow)

                Button(role: .destructive) {
                    workout.end()
                } label: {
                    Label("Terminer", systemImage: "stop.fill")
                        .frame(maxWidth: .infinity)
                }
            }
            .padding(.horizontal, 4)
        }
    }

    private static func timeString(_ seconds: Double) -> String {
        let total = Int(seconds)
        let h = total / 3600
        let m = (total % 3600) / 60
        let s = total % 60
        return h > 0
            ? String(format: "%d:%02d:%02d", h, m, s)
            : String(format: "%02d:%02d", m, s)
    }
}

/// FC de la séance, accompagnée de sa zone quand les zones sont connues.
///
/// ⚠️ La couleur ne porte jamais l'information seule : « Z3 » est écrit à côté.
/// Une pastille nue serait illisible pour un daltonien, et le contraste d'un
/// écran de montre en plein soleil ne se prête pas aux nuances.
private struct HeartRateMetric: View {
    let bpm: Int
    let zones: HeartRateZones?

    private var zone: HeartRateZone? {
        guard bpm > 0 else { return nil }
        return zones?.zone(for: bpm)
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            HStack(spacing: 6) {
                Text("FC")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
                if let zone {
                    Text(zone.label)
                        .font(.caption2.weight(.bold))
                        .padding(.horizontal, 6)
                        .padding(.vertical, 1)
                        .background(zone.color.opacity(0.25), in: Capsule())
                        .foregroundStyle(zone.color)
                }
            }
            HStack(alignment: .firstTextBaseline, spacing: 2) {
                Text("\(bpm)")
                    .font(.system(size: 30, weight: .semibold, design: .rounded))
                    // La valeur prend la couleur de la zone : d'un coup d'œil,
                    // sans lire, on sait si l'on est trop haut.
                    .foregroundStyle(zone?.color ?? .red)
                    .contentTransition(.numericText())
                Text("bpm")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
            if let zone, let bounds = zones?[zone], bounds.count == 2 {
                Text("\(zone.name) · \(bounds[0])–\(bounds[1])")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
            }
        }
        .accessibilityElement(children: .ignore)
        .accessibilityLabel("Fréquence cardiaque")
        .accessibilityValue(zone.map { "\(bpm) battements par minute, zone \($0.label), \($0.name)" }
                            ?? "\(bpm) battements par minute")
    }
}

private struct Metric: View {
    let label: String
    let value: String
    let unit: String
    let color: Color

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            Text(label)
                .font(.caption2)
                .foregroundStyle(.secondary)
            HStack(alignment: .firstTextBaseline, spacing: 2) {
                Text(value)
                    .font(.system(size: 30, weight: .semibold, design: .rounded))
                    .foregroundStyle(color)
                if !unit.isEmpty {
                    Text(unit)
                        .font(.caption)
                        .foregroundStyle(.secondary)
                }
            }
        }
    }
}

#Preview {
    ContentView()
        .environmentObject(WorkoutManager.shared)
        .environmentObject(ConnectivityManager.shared)
}