using KronaStaffTerminal.Models;
using KronaStaffTerminal.Services;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;

namespace KronaStaffTerminal;

public sealed partial class MainPage : Page
{
    private readonly TerminalStore _store = new();
    private readonly NotificationService _notifications = new();
    private readonly FingerprintScanner _scanner = new();
    private TerminalState _state = new();
    private bool _loaded;
    private TaskCompletionSource<bool>? _adminAuthCompletion;
    private ContentDialog? _adminAuthDialog;

    public MainPage()
    {
        InitializeComponent();
        _scanner.StatusChanged += message => Enqueue(() => SetStatus(message));
        _scanner.RegistrationProgress += count => Enqueue(() => SetStatus($"Регистрация отпечатка: {count}/3"));
        _scanner.RegistrationCompleted += (id, template) => Enqueue(() => _ = CompleteRegistrationAsync(id, template));
        _scanner.FingerRecognized += (id, score) => Enqueue(() => _ = HandleRecognizedFingerAsync(id, score));
    }

    private async void Page_Loaded(object sender, RoutedEventArgs e)
    {
        if (_loaded) return;
        _loaded = true;
        _state = await _store.LoadAsync();
        LoadSettings();
        ApplyStartupSetting();
        RefreshLists();
        ConnectScanner();
    }

    private void Page_Unloaded(object sender, RoutedEventArgs e) => _scanner.Dispose();

    private void ConnectScanner()
    {
        try
        {
            _scanner.Connect(_state.Settings.ReaderIndex, _state.Employees
                .Where(employee => employee.HasFingerprint)
                .Select(employee => (employee.FingerprintId, employee.FingerprintTemplate!)));
            ReaderCombo.Items.Clear();
            for (var index = 0; index < _scanner.DeviceCount; index++)
            {
                ReaderCombo.Items.Add($"SLK20R №{index + 1}");
            }
            ReaderCombo.SelectedIndex = _scanner.ReaderIndex;
            SetStatus($"Сканер SLK20R №{_scanner.ReaderIndex + 1} подключён. Зарегистрировано сотрудников: {_state.Employees.Count(employee => employee.HasFingerprint)}.", InfoBarSeverity.Success);
        }
        catch (Exception exception)
        {
            SetStatus(exception.Message, InfoBarSeverity.Error);
        }
    }

    private async void AddEmployee_Click(object sender, RoutedEventArgs e)
    {
        var name = EmployeeNameBox.Text.Trim();
        var number = PersonnelNumberBox.Text.Trim();
        if (string.IsNullOrWhiteSpace(name) || string.IsNullOrWhiteSpace(number))
        {
            SetStatus("Заполните имя и табельный номер сотрудника.", InfoBarSeverity.Warning);
            return;
        }
        if (_state.Employees.Any(employee => employee.PersonnelNumber.Equals(number, StringComparison.OrdinalIgnoreCase)))
        {
            SetStatus("Сотрудник с таким табельным номером уже есть.", InfoBarSeverity.Warning);
            return;
        }
        if (AdministratorCheckBox.IsChecked == true && SecurityConfigured &&
            !await AuthorizeAdminAsync("назначение нового администратора"))
        {
            return;
        }

        var employee = new EmployeeRecord
        {
            DisplayName = name,
            PersonnelNumber = number,
            Position = PositionBox.Text.Trim(),
            IsAdministrator = AdministratorCheckBox.IsChecked == true
        };
        _state.Employees.Add(employee);
        await _store.SaveAsync(_state);
        EmployeeNameBox.Text = "";
        PersonnelNumberBox.Text = "";
        PositionBox.Text = "";
        AdministratorCheckBox.IsChecked = false;
        RefreshLists();
        EmployeesList.SelectedItem = employee;
        SetStatus($"{name} добавлен. Теперь зарегистрируйте отпечаток.", InfoBarSeverity.Success);
    }

    private async void RegisterFingerprint_Click(object sender, RoutedEventArgs e)
    {
        if (EmployeesList.SelectedItem is not EmployeeRecord employee)
        {
            SetStatus("Сначала выберите сотрудника.", InfoBarSeverity.Warning);
            return;
        }
        if (!_scanner.IsConnected)
        {
            SetStatus("Сканер не подключён.", InfoBarSeverity.Error);
            return;
        }
        if (employee.HasFingerprint && SecurityConfigured &&
            !await AuthorizeAdminAsync("замена зарегистрированного отпечатка"))
        {
            return;
        }
        if (employee.FingerprintId <= 0)
        {
            employee.FingerprintId = _state.Employees.Select(item => item.FingerprintId).DefaultIfEmpty(0).Max() + 1;
        }
        _scanner.BeginRegistration(employee.FingerprintId);
    }

    private async Task CompleteRegistrationAsync(int fingerprintId, string template)
    {
        var employee = _state.Employees.FirstOrDefault(item => item.FingerprintId == fingerprintId);
        if (employee is null) return;
        employee.FingerprintTemplate = template;
        await _store.SaveAsync(_state);
        RefreshLists();
        TerminalMessage.Text = $"Отпечаток сотрудника «{employee.DisplayName}» зарегистрирован";
        SetStatus($"Отпечаток сотрудника «{employee.DisplayName}» зарегистрирован.", InfoBarSeverity.Success);
    }

    private async void ToggleAdministrator_Click(object sender, RoutedEventArgs e)
    {
        if (EmployeesList.SelectedItem is not EmployeeRecord employee)
        {
            SetStatus("Сначала выберите сотрудника.", InfoBarSeverity.Warning);
            return;
        }
        if (SecurityConfigured && !await AuthorizeAdminAsync("изменение прав администратора")) return;
        if (employee.IsAdministrator && _state.Employees.Count(item => item.IsAdministrator && item.HasFingerprint) <= 1)
        {
            SetStatus("Нельзя снять права с единственного администратора с зарегистрированным отпечатком.", InfoBarSeverity.Warning);
            return;
        }
        employee.IsAdministrator = !employee.IsAdministrator;
        await _store.SaveAsync(_state);
        RefreshLists();
        SetStatus(employee.IsAdministrator ? $"{employee.DisplayName} назначен администратором." : $"Права администратора у {employee.DisplayName} сняты.", InfoBarSeverity.Success);
    }

    private async void DeleteEmployee_Click(object sender, RoutedEventArgs e)
    {
        if (EmployeesList.SelectedItem is not EmployeeRecord employee)
        {
            SetStatus("Сначала выберите сотрудника.", InfoBarSeverity.Warning);
            return;
        }
        var dialog = new ContentDialog
        {
            XamlRoot = XamlRoot,
            Title = "Удалить сотрудника и отпечаток?",
            Content = $"{employee.DisplayName}, его отпечаток и право доступа будут удалены из терминала.",
            PrimaryButtonText = "Продолжить",
            CloseButtonText = "Отмена",
            DefaultButton = ContentDialogButton.Close
        };
        if (await dialog.ShowAsync() != ContentDialogResult.Primary) return;
        if (!SecurityConfigured)
        {
            SetStatus("Сначала назначьте администратора с отпечатком и установите PIN.", InfoBarSeverity.Warning);
            return;
        }
        if (!await AuthorizeAdminAsync("удаление сотрудника и отпечатка")) return;
        if (employee.IsAdministrator && _state.Employees.Count(item => item.IsAdministrator && item.HasFingerprint) <= 1)
        {
            SetStatus("Нельзя удалить единственного администратора.", InfoBarSeverity.Warning);
            return;
        }

        _state.Employees.Remove(employee);
        await _store.SaveAsync(_state);
        RefreshLists();
        ConnectScanner();
        SetStatus("Сотрудник и его отпечаток удалены.", InfoBarSeverity.Success);
    }

    private async Task HandleRecognizedFingerAsync(int fingerprintId, int score)
    {
        var employee = _state.Employees.FirstOrDefault(item => item.FingerprintId == fingerprintId);
        if (employee is null) return;
        if (_adminAuthCompletion is not null)
        {
            if (employee.IsAdministrator)
            {
                TerminalMessage.Text = $"Администратор {employee.DisplayName} подтверждён";
                _adminAuthCompletion.TrySetResult(true);
                _adminAuthDialog?.Hide();
            }
            else
            {
                SetStatus($"{employee.DisplayName} не имеет прав администратора.", InfoBarSeverity.Warning);
            }
            return;
        }
        await RecordAttendanceAsync(employee, score);
    }

    private async Task RecordAttendanceAsync(EmployeeRecord employee, int score)
    {
        var now = DateTimeOffset.UtcNow;
        var last = _state.Attendance
            .Where(item => item.EmployeeId == employee.Id)
            .OrderByDescending(item => item.OccurredAtUtc)
            .FirstOrDefault();
        var guard = TimeSpan.FromSeconds(Math.Clamp(_state.Settings.DuplicateScanGuardSeconds, 10, 3600));
        if (last is not null && now - last.OccurredAtUtc < guard)
        {
            var remaining = Math.Max(1, (int)Math.Ceiling((guard - (now - last.OccurredAtUtc)).TotalSeconds));
            TerminalMessage.Text = $"{employee.DisplayName}\nПовторный скан отклонён\nПовторите через {remaining} сек.";
            SetStatus($"Повторный скан защищён: событие не создано. Последнее событие — «{last.EventType}».", InfoBarSeverity.Informational);
            return;
        }

        var isNewDay = last is null || last.OccurredAtUtc.ToLocalTime().Date != now.ToLocalTime().Date;
        var eventType = isNewDay || last!.EventType == "Уход" ? "Приход" : "Уход";
        var record = new AttendanceRecord
        {
            EmployeeId = employee.Id,
            EmployeeName = employee.DisplayName,
            OccurredAtUtc = now,
            ReaderIndex = _scanner.ReaderIndex,
            EventType = eventType
        };
        _state.Attendance.Insert(0, record);
        await _store.SaveAsync(_state);
        RefreshLists();
        TerminalMessage.Text = $"{employee.DisplayName}\n{eventType} отмечен в {now.ToLocalTime():HH:mm}";
        SetStatus($"{eventType} отмечен. Точность распознавания: {score}.", InfoBarSeverity.Success);

        var delivery = await _notifications.SendAttendanceAsync(_state.Settings, employee.DisplayName, eventType, now.ToLocalTime());
        record.NotificationDelivered = delivery.Delivered;
        record.NotificationError = delivery.Error;
        await _store.SaveAsync(_state);
        RefreshLists();
        if (delivery.Error is not null)
        {
            SetStatus($"{eventType} сохранён, но уведомление не отправлено: {delivery.Error}", InfoBarSeverity.Warning);
        }
    }

    public async Task<bool> AuthorizeExitAsync()
    {
        if (!SecurityConfigured)
        {
            SetStatus("Выход заблокирован: сначала настройте PIN и отпечаток администратора.", InfoBarSeverity.Warning);
            return false;
        }
        return await AuthorizeAdminAsync("полное завершение терминала");
    }

    private bool SecurityConfigured =>
        !string.IsNullOrWhiteSpace(_state.Settings.AdminPinHash) &&
        _state.Employees.Any(employee => employee.IsAdministrator && employee.HasFingerprint);

    private async Task<bool> AuthorizeAdminAsync(string operation)
    {
        var pinBox = new PasswordBox { Header = "PIN администратора", PasswordRevealMode = PasswordRevealMode.Peek, MinWidth = 280 };
        var pinDialog = new ContentDialog
        {
            XamlRoot = XamlRoot,
            Title = $"Подтверждение: {operation}",
            Content = pinBox,
            PrimaryButtonText = "Продолжить",
            CloseButtonText = "Отмена",
            DefaultButton = ContentDialogButton.Primary
        };
        if (await pinDialog.ShowAsync() != ContentDialogResult.Primary) return false;
        if (!AdminPinService.Verify(pinBox.Password, _state.Settings.AdminPinSalt, _state.Settings.AdminPinHash))
        {
            SetStatus("Неверный PIN администратора.", InfoBarSeverity.Error);
            return false;
        }

        _adminAuthCompletion = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
        _adminAuthDialog = new ContentDialog
        {
            XamlRoot = XamlRoot,
            Title = "Приложите палец администратора",
            Content = "PIN принят. Теперь приложите зарегистрированный палец сотрудника с правами администратора.",
            CloseButtonText = "Отмена",
            DefaultButton = ContentDialogButton.Close
        };
        _ = ObserveAdminDialogAsync(_adminAuthDialog, _adminAuthCompletion);
        var authorized = await _adminAuthCompletion.Task;
        _adminAuthCompletion = null;
        _adminAuthDialog = null;
        SetStatus(authorized ? "Действие подтверждено администратором." : "Подтверждение отменено.", authorized ? InfoBarSeverity.Success : InfoBarSeverity.Warning);
        return authorized;
    }

    private static async Task ObserveAdminDialogAsync(ContentDialog dialog, TaskCompletionSource<bool> completion)
    {
        await dialog.ShowAsync();
        completion.TrySetResult(false);
    }

    private async void SetAdminPin_Click(object sender, RoutedEventArgs e)
    {
        var newPin = NewAdminPinBox.Password.Trim();
        if (newPin.Length < 4)
        {
            SetStatus("PIN должен содержать не менее 4 символов.", InfoBarSeverity.Warning);
            return;
        }
        if (!string.IsNullOrWhiteSpace(_state.Settings.AdminPinHash) && !await AuthorizeAdminAsync("изменение PIN")) return;
        var pin = AdminPinService.Hash(newPin);
        _state.Settings.AdminPinSalt = pin.Salt;
        _state.Settings.AdminPinHash = pin.Hash;
        NewAdminPinBox.Password = "";
        await _store.SaveAsync(_state);
        SetStatus("Новый PIN администратора сохранён.", InfoBarSeverity.Success);
    }

    private async void SaveSettings_Click(object sender, RoutedEventArgs e)
    {
        CopySettingsFromControls();
        await _store.SaveAsync(_state);
        ApplyStartupSetting();
        ConnectScanner();
        SetStatus("Настройки сохранены.", InfoBarSeverity.Success);
    }

    private async void TestNotification_Click(object sender, RoutedEventArgs e)
    {
        CopySettingsFromControls();
        var result = await _notifications.SendTestAsync(_state.Settings);
        SetStatus(result.Delivered ? "Тестовое сообщение отправлено." : result.Error ?? "Включите Telegram или MAX и заполните реквизиты.", result.Delivered ? InfoBarSeverity.Success : InfoBarSeverity.Warning);
    }

    private void CopySettingsFromControls()
    {
        _state.Settings.ReaderIndex = Math.Max(0, ReaderCombo.SelectedIndex);
        _state.Settings.StartWithWindows = StartWithWindowsSwitch.IsOn;
        _state.Settings.DuplicateScanGuardSeconds = double.IsNaN(DuplicateGuardBox.Value) ? 120 : Math.Clamp((int)DuplicateGuardBox.Value, 10, 3600);
        _state.Settings.TelegramEnabled = TelegramEnabledSwitch.IsOn;
        _state.Settings.TelegramBotToken = TelegramTokenBox.Password.Trim();
        _state.Settings.TelegramChatId = TelegramChatBox.Text.Trim();
        _state.Settings.MaxEnabled = MaxEnabledSwitch.IsOn;
        _state.Settings.MaxBotToken = MaxTokenBox.Password.Trim();
        _state.Settings.MaxChatId = MaxChatBox.Text.Trim();
    }

    private void LoadSettings()
    {
        StartWithWindowsSwitch.IsOn = _state.Settings.StartWithWindows;
        DuplicateGuardBox.Value = Math.Clamp(_state.Settings.DuplicateScanGuardSeconds, 10, 3600);
        TelegramEnabledSwitch.IsOn = _state.Settings.TelegramEnabled;
        TelegramTokenBox.Password = _state.Settings.TelegramBotToken;
        TelegramChatBox.Text = _state.Settings.TelegramChatId;
        MaxEnabledSwitch.IsOn = _state.Settings.MaxEnabled;
        MaxTokenBox.Password = _state.Settings.MaxBotToken;
        MaxChatBox.Text = _state.Settings.MaxChatId;
    }

    private void ApplyStartupSetting()
    {
        try
        {
            StartupService.SetEnabled(_state.Settings.StartWithWindows);
            StartWithWindowsSwitch.IsOn = StartupService.IsEnabled();
        }
        catch (Exception exception)
        {
            SetStatus($"Не удалось изменить автозагрузку: {exception.Message}", InfoBarSeverity.Warning);
        }
    }

    private void RefreshLists()
    {
        EmployeesList.ItemsSource = null;
        EmployeesList.ItemsSource = _state.Employees.OrderBy(employee => employee.DisplayName).ToList();
        AttendanceList.ItemsSource = null;
        AttendanceList.ItemsSource = _state.Attendance.OrderByDescending(item => item.OccurredAtUtc).Take(100).ToList();
    }

    private void SetStatus(string message, InfoBarSeverity severity = InfoBarSeverity.Informational)
    {
        StatusBar.Message = message;
        StatusBar.Severity = severity;
        StatusBar.IsOpen = true;
    }

    private static void Enqueue(Action action) => App.DispatcherQueue.TryEnqueue(() => action());
}