using System;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace InstaSoftOfficeTool.Pages
{
    public partial class ProductKeyDialog : UserControl
    {
        private TaskCompletionSource<string> _tcs;
        private readonly TextBox[] _keyBoxes;
        private bool _suppress;

        public ProductKeyDialog()
        {
            InitializeComponent();
            _keyBoxes = new[] { DKey1, DKey2, DKey3, DKey4, DKey5 };

            foreach (var box in _keyBoxes)
            {
                DataObject.AddPastingHandler(box, OnPaste);
            }
        }

        public Task<string> ShowAsync()
        {
            foreach (var box in _keyBoxes) box.Text = "";
            BtnOk.IsEnabled = false;
            Visibility = Visibility.Visible;
            DKey1.Focus();
            _tcs = new TaskCompletionSource<string>();
            return _tcs.Task;
        }

        private string GetFullKey()
        {
            return string.Join("-", DKey1.Text, DKey2.Text, DKey3.Text, DKey4.Text, DKey5.Text).ToUpper();
        }

        private bool IsKeyComplete()
        {
            foreach (var box in _keyBoxes)
            {
                if (box.Text.Length != 5 || !Regex.IsMatch(box.Text, "^[A-Za-z0-9]{5}$"))
                    return false;
            }
            return true;
        }

        private void KeyBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            if (_suppress) return;
            var tb = (TextBox)sender;

            var cleaned = Regex.Replace(tb.Text, "[^A-Za-z0-9]", "");
            if (cleaned != tb.Text)
            {
                _suppress = true;
                tb.Text = cleaned;
                tb.CaretIndex = cleaned.Length;
                _suppress = false;
            }

            if (tb.Text.Length == 5)
            {
                for (int i = 0; i < _keyBoxes.Length - 1; i++)
                {
                    if (_keyBoxes[i] == tb)
                    {
                        _keyBoxes[i + 1].Focus();
                        break;
                    }
                }
            }

            BtnOk.IsEnabled = IsKeyComplete();
        }

        private void OnPaste(object sender, DataObjectPastingEventArgs e)
        {
            if (!e.DataObject.GetDataPresent(typeof(string))) return;
            var pasted = (string)e.DataObject.GetData(typeof(string));
            var allAlphaNum = Regex.Replace(pasted, "[^A-Za-z0-9]", "");

            if (allAlphaNum.Length <= 5) return;

            e.CancelCommand();
            _suppress = true;
            for (int i = 0; i < 5; i++)
            {
                int start = i * 5;
                if (start < allAlphaNum.Length)
                {
                    int len = Math.Min(5, allAlphaNum.Length - start);
                    _keyBoxes[i].Text = allAlphaNum.Substring(start, len).ToUpper();
                }
            }
            _suppress = false;
            _keyBoxes[4].Focus();
            _keyBoxes[4].CaretIndex = _keyBoxes[4].Text.Length;
            BtnOk.IsEnabled = IsKeyComplete();
        }

        private void BtnOk_Click(object sender, RoutedEventArgs e)
        {
            Visibility = Visibility.Collapsed;
            _tcs?.TrySetResult(GetFullKey());
        }

        private void BtnCancel_Click(object sender, RoutedEventArgs e)
        {
            Visibility = Visibility.Collapsed;
            _tcs?.TrySetResult(null);
        }

        private void Backdrop_MouseDown(object sender, MouseButtonEventArgs e)
        {
            Visibility = Visibility.Collapsed;
            _tcs?.TrySetResult(null);
        }
    }
}