import SwiftUI

// MARK: - SettingsView

struct SettingsView: View {
    @EnvironmentObject var authManager: AuthManager
    @AppStorage("colorScheme") private var colorSchemeRaw: String = "dark"
    @State private var profile: UserProfile?
    @State private var isLoading = true
    @State private var isSaving = false
    @State private var showPasswordChange = false

    // Profile fields
    @State private var telegramChatId = ""
    @State private var morningNotification = true
    @State private var eveningNotification = true
    @State private var morningTime = "09:00"
    @State private var eveningTime = "21:00"
    @State private var timezone = "Europe/Moscow"
    @State private var username = ""

    var isDark: Bool { colorSchemeRaw != "light" }

    let timezones = [
        "Europe/Moscow", "Europe/Kaliningrad", "Europe/Samara", "Asia/Yekaterinburg",
        "Asia/Omsk", "Asia/Krasnoyarsk", "Asia/Irkutsk", "Asia/Yakutsk",
        "Asia/Vladivostok", "Asia/Magadan", "Asia/Kamchatka",
        "UTC", "Europe/London", "Europe/Berlin", "Europe/Paris", "America/New_York"
    ]

    var body: some View {
        ZStack {
            Color(hex: "0a0a1a").ignoresSafeArea()
            ScrollView {
                VStack(spacing: 0) {
                    // Header / Avatar
                    VStack(spacing: 12) {
                        ZStack {
                            Circle().fill(Color(hex: "0D9488").opacity(0.2)).frame(width: 80, height: 80)
                            Text(String(authManager.userName.prefix(1)).uppercased())
                                .font(.largeTitle.bold()).foregroundColor(Color(hex: "0D9488"))
                        }
                        Text(authManager.userName).font(.title2.bold()).foregroundColor(.white)
                        Text("ID: \(authManager.userId)").font(.caption).foregroundColor(Color(hex: "8888aa"))
                    }
                    .padding(.top, 24)
                    .padding(.bottom, 28)

                    if isLoading {
                        ProgressView().tint(Color(hex: "0D9488")).padding(.top, 20)
                    } else {
                        VStack(spacing: 20) {
                            // MARK: Appearance
                            SettingsSection(title: "Внешний вид") {
                                SettingsToggle(icon: "moon.fill", title: isDark ? "Тёмная тема" : "Светлая тема", color: "6366f1", isOn: isDark) {
                                    colorSchemeRaw = isDark ? "light" : "dark"
                                }
                            }

                            // MARK: Profile
                            SettingsSection(title: "Профиль") {
                                VStack(spacing: 8) {
                                    Label("Имя пользователя", systemImage: "person.fill")
                                        .font(.caption).foregroundColor(Color(hex: "8888aa"))
                                        .frame(maxWidth: .infinity, alignment: .leading)
                                    TextField("Username", text: $username)
                                        .foregroundColor(.white).padding(14)
                                        .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.07)))
                                }
                                .padding(.horizontal, 4)

                                SettingsButton(icon: "lock.fill", title: "Сменить пароль", color: "7c3aed") {
                                    showPasswordChange = true
                                }
                            }

                            // MARK: Telegram
                            SettingsSection(title: "Telegram Бот") {
                                VStack(alignment: .leading, spacing: 8) {
                                    Label("Chat ID", systemImage: "paperplane.fill")
                                        .font(.caption).foregroundColor(Color(hex: "8888aa"))
                                    TextField("Например: 123456789", text: $telegramChatId)
                                        .keyboardType(.numbersAndPunctuation)
                                        .foregroundColor(.white).padding(14)
                                        .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.07)))
                                    HStack(spacing: 4) {
                                        Image(systemName: "info.circle").font(.caption2).foregroundColor(Color(hex: "0D9488"))
                                        Text("Напишите /start боту @pulse_tracking_bot, чтобы получить Chat ID")
                                            .font(.caption2).foregroundColor(Color(hex: "8888aa"))
                                    }
                                }
                                .padding(.horizontal, 4)
                            }

                            // MARK: Notifications
                            SettingsSection(title: "Уведомления") {
                                VStack(spacing: 12) {
                                    SettingsToggle(icon: "sunrise.fill", title: "Утренние уведомления", color: "ffa502", isOn: morningNotification) {
                                        morningNotification.toggle()
                                    }
                                    if morningNotification {
                                        HStack {
                                            Text("Время").font(.callout).foregroundColor(Color(hex: "8888aa"))
                                            Spacer()
                                            TextField("09:00", text: $morningTime)
                                                .keyboardType(.numbersAndPunctuation)
                                                .foregroundColor(.white)
                                                .multilineTextAlignment(.trailing)
                                                .frame(width: 60)
                                        }
                                        .padding(.horizontal, 4)
                                    }

                                    Divider().background(Color.white.opacity(0.08))

                                    SettingsToggle(icon: "moon.stars.fill", title: "Вечерние уведомления", color: "6366f1", isOn: eveningNotification) {
                                        eveningNotification.toggle()
                                    }
                                    if eveningNotification {
                                        HStack {
                                            Text("Время").font(.callout).foregroundColor(Color(hex: "8888aa"))
                                            Spacer()
                                            TextField("21:00", text: $eveningTime)
                                                .keyboardType(.numbersAndPunctuation)
                                                .foregroundColor(.white)
                                                .multilineTextAlignment(.trailing)
                                                .frame(width: 60)
                                        }
                                        .padding(.horizontal, 4)
                                    }
                                }
                            }

                            // MARK: Timezone
                            SettingsSection(title: "Часовой пояс") {
                                VStack(alignment: .leading, spacing: 8) {
                                    Label("Выберите часовой пояс", systemImage: "clock.fill")
                                        .font(.caption).foregroundColor(Color(hex: "8888aa"))
                                    Picker("Часовой пояс", selection: $timezone) {
                                        ForEach(timezones, id: \.self) { tz in Text(tz).tag(tz) }
                                    }
                                    .pickerStyle(.wheel)
                                    .frame(height: 120)
                                    .clipped()
                                    .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.04)))
                                }
                                .padding(.horizontal, 4)
                            }

                            // MARK: Save Button
                            Button(action: { Task { await saveProfile() } }) {
                                HStack {
                                    if isSaving { ProgressView().tint(.black).scaleEffect(0.8) }
                                    else { Text("Сохранить изменения").font(.headline).foregroundColor(.black) }
                                }
                                .frame(maxWidth: .infinity).padding()
                                .background(LinearGradient(colors: [Color(hex: "0D9488"), Color(hex: "14b8a6")], startPoint: .leading, endPoint: .trailing))
                                .cornerRadius(14)
                            }
                            .disabled(isSaving)
                            .padding(.horizontal)

                            // MARK: Logout
                            Button(action: { authManager.logout() }) {
                                HStack {
                                    Image(systemName: "rectangle.portrait.and.arrow.right")
                                    Text("Выйти из аккаунта")
                                }
                                .font(.callout.bold())
                                .foregroundColor(Color(hex: "ff4757"))
                                .frame(maxWidth: .infinity).padding()
                                .background(RoundedRectangle(cornerRadius: 14).fill(Color(hex: "ff4757").opacity(0.1)))
                                .overlay(RoundedRectangle(cornerRadius: 14).stroke(Color(hex: "ff4757").opacity(0.3), lineWidth: 1))
                            }
                            .padding(.horizontal)

                            Text("Pulse v1.1 • Made with ❤️").font(.caption).foregroundColor(Color(hex: "8888aa"))
                                .padding(.bottom, 20)
                        }
                    }
                }
            }
        }
        .task { await loadProfile() }
        .sheet(isPresented: $showPasswordChange) {
            ChangePasswordView(isPresented: $showPasswordChange)
                .presentationDetents([.medium])
                .presentationDragIndicator(.visible)
                .presentationBackground(Color(hex: "0a0a1a"))
        }
    }

    func loadProfile() async {
        isLoading = true
        username = authManager.userName
        if let p = try? await APIService.shared.getProfile(token: authManager.token) {
            profile = p
            telegramChatId = p.telegramChatId ?? ""
            morningNotification = p.morningNotification ?? true
            eveningNotification = p.eveningNotification ?? true
            morningTime = p.morningTime ?? "09:00"
            eveningTime = p.eveningTime ?? "21:00"
            timezone = p.timezone ?? "Europe/Moscow"
        }
        isLoading = false
    }

    func saveProfile() async {
        isSaving = true
        let req = UpdateProfileRequest(
            telegramChatId: telegramChatId.isEmpty ? nil : telegramChatId,
            morningNotification: morningNotification,
            eveningNotification: eveningNotification,
            morningTime: morningTime,
            eveningTime: eveningTime,
            timezone: timezone
        )
        _ = try? await APIService.shared.updateProfile(token: authManager.token, request: req)
        // Update username if changed
        if username != authManager.userName {
            var req2 = URLRequest(url: URL(string: "https://api.digital-home.site/auth/me")!)
            req2.httpMethod = "PUT"
            req2.setValue("application/json", forHTTPHeaderField: "Content-Type")
            req2.setValue("Bearer \(authManager.token)", forHTTPHeaderField: "Authorization")
            req2.httpBody = try? JSONEncoder().encode(["username": username])
            _ = try? await URLSession.shared.data(for: req2)
            await MainActor.run { authManager.userName = username; UserDefaults.standard.set(username, forKey: "userName") }
        }
        isSaving = false
    }
}

// MARK: - SettingsSection

struct SettingsSection<Content: View>: View {
    let title: String
    @ViewBuilder let content: () -> Content
    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text(title).font(.subheadline.bold()).foregroundColor(Color(hex: "8888aa")).padding(.horizontal)
            VStack(spacing: 8) {
                content()
            }
            .padding(16)
            .background(RoundedRectangle(cornerRadius: 16).fill(Color.white.opacity(0.04)))
            .padding(.horizontal)
        }
    }
}

// MARK: - SettingsToggle

struct SettingsToggle: View {
    let icon: String
    let title: String
    let color: String
    let isOn: Bool
    let onToggle: () -> Void
    var body: some View {
        HStack(spacing: 14) {
            ZStack {
                RoundedRectangle(cornerRadius: 8).fill(Color(hex: color).opacity(0.2)).frame(width: 36, height: 36)
                Image(systemName: icon).foregroundColor(Color(hex: color)).font(.subheadline)
            }
            Text(title).font(.callout).foregroundColor(.white)
            Spacer()
            Toggle("", isOn: Binding(get: { isOn }, set: { _ in onToggle() }))
                .tint(Color(hex: "0D9488"))
        }
    }
}

// MARK: - SettingsButton

struct SettingsButton: View {
    let icon: String
    let title: String
    let color: String
    let action: () -> Void
    var body: some View {
        Button(action: action) {
            HStack(spacing: 14) {
                ZStack {
                    RoundedRectangle(cornerRadius: 8).fill(Color(hex: color).opacity(0.2)).frame(width: 36, height: 36)
                    Image(systemName: icon).foregroundColor(Color(hex: color)).font(.subheadline)
                }
                Text(title).font(.callout).foregroundColor(.white)
                Spacer()
                Image(systemName: "chevron.right").foregroundColor(Color(hex: "8888aa")).font(.caption)
            }
        }
    }
}