import SwiftUI

struct NotificationSettingsView: View {
    @EnvironmentObject var settings: Settings
    @EnvironmentObject var notificationManager: NotificationManager
    @EnvironmentObject var apiClient: APIClient
    @State private var showingPermissionAlert = false
    @State private var boards: [Board] = []
    @State private var isLoadingBoards = false
    
    var body: some View {
        Form {
            Section(header: Text("Уведомления")) {
                Toggle("Включить уведомления", isOn: $settings.notificationsEnabled)
                    .onChange(of: settings.notificationsEnabled) { newValue in
                        if newValue {
                            requestNotificationPermission()
                        }
                        settings.saveSettings()
                    }
                
                if settings.notificationsEnabled {
                    HStack {
                        Text("Интервал проверки")
                        Spacer()
                        Picker("", selection: $settings.notificationInterval) {
                            Text("5 мин").tag(300)
                            Text("15 мин").tag(900)
                            Text("30 мин").tag(1800)
                            Text("1 час").tag(3600)
                        }
                        .pickerStyle(MenuPickerStyle())
                    }
                    .onChange(of: settings.notificationInterval) { _ in
                        settings.saveSettings()
                    }
                }
            }
            
            if settings.notificationsEnabled {
                Section(header: Text("Подписки на доски")) {
                    if isLoadingBoards {
                        HStack {
                            ProgressView()
                                .scaleEffect(0.8)
                            Text("Загрузка досок...")
                                .foregroundColor(.secondary)
                        }
                    } else {
                        ForEach(boards) { board in
                            HStack {
                                VStack(alignment: .leading, spacing: 2) {
                                    Text("/\(board.code)/")
                                        .font(.headline)
                                    Text(board.description.isEmpty ? "Без описания" : board.description)
                                        .font(.caption)
                                        .foregroundColor(.secondary)
                                        .lineLimit(1)
                                }
                                
                                Spacer()
                                
                                Toggle("", isOn: Binding(
                                    get: { notificationManager.subscribedBoards.contains(board.code) },
                                    set: { isSubscribed in
                                        if isSubscribed {
                                            notificationManager.subscribeToBoard(board.code)
                                        } else {
                                            notificationManager.unsubscribeFromBoard(board.code)
                                        }
                                    }
                                ))
                            }
                        }
                    }
                }
            }
        }
        .navigationTitle("Уведомления")
        .onAppear {
            if boards.isEmpty {
                loadBoards()
            }
        }
        .alert("Разрешить уведомления", isPresented: $showingPermissionAlert) {
            Button("Настройки") {
                if let url = URL(string: UIApplication.openSettingsURLString) {
                    UIApplication.shared.open(url)
                }
            }
            Button("Отмена", role: .cancel) {
                settings.notificationsEnabled = false
            }
        } message: {
            Text("Для получения уведомлений о новых тредах необходимо разрешить уведомления в настройках")
        }
    }
    
    private func loadBoards() {
        isLoadingBoards = true
        
        apiClient.getBoards { result in
            DispatchQueue.main.async {
                self.isLoadingBoards = false
                
                switch result {
                case .success(let loadedBoards):
                    self.boards = loadedBoards
                case .failure:
                    self.boards = []
                }
            }
        }
    }
    
    private func requestNotificationPermission() {
        notificationManager.requestPermission { granted in
            if !granted {
                showingPermissionAlert = true
            }
        }
    }
}