using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Automation.Peers;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Input;
using Comal.Classes;
using InABox.Clients;
using InABox.Configuration;
using InABox.Core;
using InABox.Wpf;
using InABox.WPF;
using PRSDesktop.Forms;
using ValidationResult = InABox.Clients.ValidationResult;

namespace PRSDesktop;

/// <summary>
///     Interaction logic for PinLogin.xaml
/// </summary>
public partial class PinLogin : ThemableWindow
{
    private bool _isloggedin = false;

    private enum Page
    {
        PIN,
        PASSWORD,
        _2FA
    }

    private bool PINPage;
    private Page CurrentPage;

    private bool Checking = false;

    private List<TextBox> codeInputs = new();

    public PinLogin(string version, ValidationResult status)
    {
        InitializeComponent();

        Title = $"{(String.Equals(App.Profile?.ToUpper(), "DEFAULT") ? "PRS Desktop" : App.Profile)} (Release {CoreUtils.GetVersion()})";

        foreach (var codeInput in CodeInput.Children)
        {
            var tb = codeInput as TextBox;

            tb.PreviewKeyDown += Code2FA_PreviewKeyDown;
            tb.PreviewTextInput += Code2FA_Preview;
            tb.TextChanged += Code2FA_TextChanged;

            codeInputs.Add(tb);
        }

        UserID.Text = App.DatabaseSettings.UserID;
        Password.Password = App.DatabaseSettings.Password;

        if (status == ValidationResult.PASSWORD_EXPIRED)
        {
            status = TryValidation("", status);
        }

        PINPage = App.DatabaseSettings.LoginType == LoginType.PIN;
        if (status == ValidationResult.REQUIRE_2FA)
            Show2FAPage();
        else if (PINPage)
            ShowPINPage();
        else
            ShowPasswordPage();

        //AutoLogin.IsChecked = _settings.Autologin;
    }

    private void ShowPINPage()
    {
        CurrentPage = Page.PIN;

        OverallLayout.ColumnDefinitions[0].Width = new GridLength(1, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[1].Width = new GridLength(0, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[2].Width = new GridLength(0, GridUnitType.Star);

        PINLayout.RowDefinitions[3].Height = new GridLength(70, GridUnitType.Pixel);
        PINLayout.RowDefinitions[4].Height = new GridLength(70, GridUnitType.Pixel);

        Layout_2FA.RowDefinitions[3].Height = new GridLength(0, GridUnitType.Pixel);
    }

    private void ShowPasswordPage()
    {
        CurrentPage = Page.PASSWORD;

        OverallLayout.ColumnDefinitions[0].Width = new GridLength(0, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[1].Width = new GridLength(1, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[2].Width = new GridLength(0, GridUnitType.Star);

        PINLayout.RowDefinitions[3].Height = new GridLength(0, GridUnitType.Pixel);
        PINLayout.RowDefinitions[4].Height = new GridLength(0, GridUnitType.Pixel);

        Layout_2FA.RowDefinitions[3].Height = new GridLength(0, GridUnitType.Pixel);
    }

    private void Show2FAPage()
    {
        CurrentPage = Page._2FA;

        OverallLayout.ColumnDefinitions[0].Width = new GridLength(0, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[1].Width = new GridLength(0, GridUnitType.Star);
        OverallLayout.ColumnDefinitions[2].Width = new GridLength(1, GridUnitType.Star);

        PINLayout.RowDefinitions[3].Height = new GridLength(0, GridUnitType.Pixel);
        PINLayout.RowDefinitions[4].Height = new GridLength(0, GridUnitType.Pixel);

        Layout_2FA.RowDefinitions[3].Height = new GridLength(70, GridUnitType.Pixel);

        foreach (var codeInput in codeInputs)
        {
            codeInput.Text = "";
        }
        codeInputs[0].Focus();

        Label_2FA.Content = string.Format("Please enter the code that was sent to {0}", ClientFactory.Recipient2FA);
    }

    private void ViewPINClick(object sender, RoutedEventArgs e)
    {
        ShowPINPage();
        PIN.Focus();
        PINPage = true;
    }

    private void ViewPasswordClick(object sender, RoutedEventArgs e)
    {
        ShowPasswordPage();
        UserID.Focus();
        PINPage = false;
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        var button = (Button)sender;
        PIN.Password += button.Content;
    }

    private void Back_Click(object sender, RoutedEventArgs e)
    {
        if (!string.IsNullOrEmpty(PIN.Password))
            PIN.Password = PIN.Password[..^1]; //.Reverse().Skip(1).Reverse().ToString();
    }

    private void Window_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        if(CurrentPage == Page._2FA)
        {
            if (e.Key == Key.Enter || e.Key == Key.Return)
            {
                e.Handled = true;
                Do2FA();
            }
            return;
        }
        if (CurrentPage != Page.PIN)
            return;

        e.Handled = true;

        Button button = null;
        if (e.Key == Key.Enter || e.Key == Key.Return)
            button = OK;
        else if (e.Key == Key.D1 || e.Key == Key.NumPad1)
            button = Key1;
        else if (e.Key == Key.D2 || e.Key == Key.NumPad2)
            button = Key2;
        else if (e.Key == Key.D3 || e.Key == Key.NumPad3)
            button = Key3;
        else if (e.Key == Key.D4 || e.Key == Key.NumPad4)
            button = Key4;
        else if (e.Key == Key.D5 || e.Key == Key.NumPad5)
            button = Key5;
        else if (e.Key == Key.D6 || e.Key == Key.NumPad6)
            button = Key6;
        else if (e.Key == Key.D7 || e.Key == Key.NumPad7)
            button = Key7;
        else if (e.Key == Key.D8 || e.Key == Key.NumPad8)
            button = Key8;
        else if (e.Key == Key.D9 || e.Key == Key.NumPad9)
            button = Key9;
        else if (e.Key == Key.D0 || e.Key == Key.NumPad0)
            button = Key0;
        else if (e.Key == Key.Back)
            button = Back;


        if (button == null || !button.IsEnabled)
            return;

        var peer = new ButtonAutomationPeer(button);
        var invokeProv = peer.GetPattern(PatternInterface.Invoke) as IInvokeProvider;
        invokeProv.Invoke();
    }

    private void PINChanged(object sender, RoutedEventArgs e)
    {
        Back.IsEnabled = !string.IsNullOrEmpty(PIN.Password);
        OK.IsEnabled = !string.IsNullOrEmpty(PIN.Password);
    }

    private string? ShowChangePassword(string userID)
    {
        using (var session = new BypassSession())
        {
            var user = new Client<User>().Query(
                new Filter<User>(x => x.UserID).IsEqualTo(userID),
                new Columns<User>(x => x.ID)).Rows.FirstOrDefault()?.ToObject<User>();
            if(user != null)
            {
                var changePassword = new ChangePassword(user.ID);
                if (changePassword.ShowDialog() == true && changePassword.Password != null)
                {
                    ChangePassword.ChangeUserPassword(user, changePassword.Password);
                    new Client<User>().Save(user, "Changed password");
                    return changePassword.Password;
                }
                else
                {
                    if (PINPage)
                        ShowPINPage();
                    else
                        ShowPasswordPage();
                }
            }
            else
            {
                MessageBox.Show($"No user with username {userID}");
            }
        }
        return null;
    }

    private void OK_Click(object sender, RoutedEventArgs e)
    {
        ValidationResult? result;
        using (new WaitCursor())
        {
            try
            {
                result = ClientFactory.Validate(PIN.Password);
            }
            catch(Exception err)
            {
                Logger.Send(LogType.Error, ClientFactory.UserID, $"Error connecting to server: {CoreUtils.FormatException(err)}");
                MessageBox.Show("Error connecting to server! Check the server URL and port number.");
                result = null;
            }
        }

        if (result == ValidationResult.REQUIRE_2FA)
        {
            Show2FAPage();
            return;
        }

        var bOK = result == ValidationResult.VALID;
        if (bOK)
        {
            App.DatabaseSettings.LoginType = LoginType.PIN;
            App.DatabaseSettings.Autologin = false;
            App.DatabaseSettings.UserID = "";
            App.DatabaseSettings.Password = "";
            DialogResult = true;
            Close();
        }
        else
        {
            if(result != null)
            {
                MessageBox.Show("Invalid PIN!");
            }
            PIN.Password = "";
        }
    }

    private void UserID_TextChanged(object sender, TextChangedEventArgs e)
    {
        Login.IsEnabled = !string.IsNullOrEmpty(UserID.Text) && !string.IsNullOrEmpty(Password.Password);
    }

    private void Password_PasswordChanged(object sender, RoutedEventArgs e)
    {
        Login.IsEnabled = !string.IsNullOrEmpty(UserID.Text) && !string.IsNullOrEmpty(Password.Password);
    }

    private void AutoLogin_Checked(object sender, RoutedEventArgs e)
    {
    }

    private ValidationResult TryValidation(string password, ValidationResult? result = null)
    {
        while (true)
        {
            if(result == null)
            {
                using (new WaitCursor())
                {
                    try
                    {
                        result = ClientFactory.Validate(UserID.Text, password);
                    }
                    catch (Exception e)
                    {
                        Logger.Send(LogType.Error, ClientFactory.UserID, $"Error connecting to server: {CoreUtils.FormatException(e)}");
                        MessageBox.Show("Error connecting to server! Check the server URL and port number.");
                    }
                }
            }
            if (result == ValidationResult.PASSWORD_EXPIRED)
            {
                MessageBox.Show("Your password has expired!");
                var newPassword = ShowChangePassword(UserID.Text);
                if (newPassword == null)
                {
                    break;
                }
                else
                {
                    password = newPassword;
                    Password.Clear();
                }
            }
            else
            {
                break;
            }
            result = null;
        }
        return result ?? ValidationResult.INVALID;
    }

    private void Login_Click(object sender, RoutedEventArgs e)
    {
        ValidationResult result = TryValidation(Password.Password);

        if (result == ValidationResult.REQUIRE_2FA)
        {
            Show2FAPage();
            return;
        }

        var bOK = result == ValidationResult.VALID;

        if (bOK)
        {
            //if (AutoLogin.IsChecked == true)
            //{
            //    _settings.LoginType = LoginType.UserID;
            //    _settings.UserID = UserID.Text;
            //    _settings.Password = Password.Password;
            //    _settings.Autologin = true;
            //    new LocalConfiguration<DatabaseSettings>().Save(_settings);
            //}
            DialogResult = true;
            Close();
        }
        else
        {
            MessageBox.Show("Login Failed!");
        }
    }

    private void Window_Closing(object sender, CancelEventArgs e)
    {
        //e.Cancel = ClientFactory.UserGuid == Guid.Empty;
        if(!PINPage && DialogResult == true && App.DatabaseSettings.Autologin
            && App.DatabaseSettings.UserID == UserID.Text
            && App.DatabaseSettings.Password != Password.Password)
        {
            if(MessageBox.Show("You have logged in with a new password. Would you like to update your password in your settings so that you login automatically next time?",
                "Update password?",
                MessageBoxButton.YesNo) == MessageBoxResult.Yes)
            {
                App.DatabaseSettings.Password = Password.Password;
                App.SaveDatabaseSettings();
            }
        }
    }

    private void Password_KeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter || e.Key == Key.Return)
        {
            e.Handled = true;
            var peer = new ButtonAutomationPeer(Login);
            var invokeProv = peer.GetPattern(PatternInterface.Invoke) as IInvokeProvider;
            invokeProv.Invoke();
        }
    }

    private void UserID_KeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter || e.Key == Key.Return)
        {
            e.Handled = true;
            Password.Focus();
        }
    }

    private bool HasFilled2FABoxes()
    {
        foreach (var codeInput in CodeInput.Children)
        {
            var digit = (codeInput as TextBox)?.Text;
            if (digit == null || digit.Length != 1 || !char.IsDigit(digit[0]))
            {
                return false;
            }
        }
        return true;
    }

    private void Do2FA(bool showMessage = true)
    {
        if (Checking) return;

        Checking = true;
        var code = "";
        foreach (var codeInput in CodeInput.Children)
        {
            var digit = (codeInput as TextBox)?.Text;
            if (digit != null && digit.Length == 1 && char.IsDigit(digit[0]))
            {
                code += digit[0];
            }
            else
            {
                MessageBox.Show("All boxes must be filled and must contain a number");
                return;
            }
        }

        Task.Run(() =>
        {
            if (ClientFactory.Check2FA(code))
            {
                Dispatcher.Invoke(() =>
                {
                    DialogResult = true;

                    Close();
                });
            }
            else
            {
                MessageBox.Show("Code is incorrect!");
                Checking = false;
            }
        });
    }

    private void Click_2FA(object sender, RoutedEventArgs e)
    {
        Do2FA();
    }

    private void Back_2FA(object sender, RoutedEventArgs e)
    {
        ClientFactory.InvalidateUser();

        if (PINPage)
            ShowPINPage();
        else
            ShowPasswordPage();
    }

    private void MoveFocus()
    {
        var element = Keyboard.FocusedElement;
        if (element is TextBox)
        {
            var tb = element as TextBox;
            if (tb.Text.Length == 1)
            {
                var index = codeInputs.IndexOf(tb) + 1;
                if (index >= codeInputs.Count)
                {
                    Focus();
                    if (HasFilled2FABoxes())
                    {
                        Do2FA();
                    }
                }
                else
                {
                    var nextChild = codeInputs[index];
                    nextChild.Focus();
                }
            }
        }
    }

    private void Code2FA_Preview(object sender, TextCompositionEventArgs e)
    {
        var tb = sender as TextBox;
        var oldText = tb!.Text;
        var newText = e.Text;
        var valid = newText.Length == 0 || (newText.Length == 1 && char.IsDigit(newText[0]));
        if (oldText.Length != 0 && valid)
        {
            tb.Text = "";
        }
        e.Handled = !valid;
        if (!valid && oldText.Length + newText.Length > 0)
        {
            MoveFocus();
        }
    }

    private void Code2FA_TextChanged(object sender, TextChangedEventArgs e)
    {
        MoveFocus();
    }

    private void Code2FA_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        if (sender is TextBox tb)
        {
            var currentIndex = codeInputs.IndexOf(tb);
            int? newIndex = null;

            switch (e.Key)
            {
                case Key.Back:
                    tb.Text = "";
                    newIndex = Math.Max(currentIndex - 1, 0);
                    e.Handled = true;
                    break;
                case Key.Left:
                    newIndex = Math.Max(currentIndex - 1, 0);
                    e.Handled = true;
                    break;
                case Key.Right:
                    newIndex = Math.Min(currentIndex + 1, codeInputs.Count - 1);
                    e.Handled = true;
                    break;
            }

            if(newIndex != null)
            {
                var nextChild = codeInputs[newIndex ?? 0];
                nextChild.Focus();
            }
        }
    }
}