using System;
using System.Linq;
using Artemis.Core;
using Artemis.Core.Services;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Data;
using Avalonia.Input;
using Avalonia.Interactivity;
using Avalonia.Markup.Xaml;
using Humanizer;
using Material.Icons;

namespace Artemis.UI.Shared
{
    /// <summary>
    /// Represents a control that can be used to display or edit <see cref="Core.Hotkey"/> instances.
    /// </summary>
    public class HotkeyBox : UserControl
    {
        private readonly TextBox _displayTextBox;

        /// <summary>
        /// Creates a new instance of the <see cref="HotkeyBox"/> class
        /// </summary>
        public HotkeyBox()
        {
            InitializeComponent();

            _displayTextBox = this.Find<TextBox>("DisplayTextBox");
            _displayTextBox.KeyDown += DisplayTextBoxOnKeyDown;
            _displayTextBox.KeyUp += DisplayTextBoxOnKeyUp;
            UpdateDisplayTextBox();
        }

        private static void HotkeyChanging(IAvaloniaObject sender, bool before)
        {
            ((HotkeyBox) sender).UpdateDisplayTextBox();
        }

        private void DisplayTextBoxOnKeyDown(object? sender, KeyEventArgs e)
        {
            if (e.Key >= Key.LeftShift && e.Key <= Key.RightAlt)
                return;

            Hotkey ??= new Hotkey();
            Hotkey.Key = (KeyboardKey?) e.Key;
            Hotkey.Modifiers = (KeyboardModifierKey?) e.KeyModifiers;
            UpdateDisplayTextBox();

            e.Handled = true;
        }

        private void DisplayTextBoxOnKeyUp(object? sender, KeyEventArgs e)
        {
            if (e.KeyModifiers == KeyModifiers.None)
                FocusManager.Instance?.Focus(null);

            e.Handled = true;
        }

        private void UpdateDisplayTextBox()
        {
            string? display = null;
            if (Hotkey?.Modifiers != null)
                display = string.Join("+", Enum.GetValues<KeyboardModifierKey>().Skip(1).Where(m => Hotkey.Modifiers.Value.HasFlag(m)).Select(v => v.Humanize()));
            if (Hotkey?.Key != null)
                display = string.IsNullOrEmpty(display) ? Hotkey.Key.ToString() : $"{display}+{Hotkey.Key}";

            _displayTextBox.Text = display;
            _displayTextBox.CaretIndex = _displayTextBox.Text?.Length ?? 0;
        }

        private void InitializeComponent()
        {
            AvaloniaXamlLoader.Load(this);
        }

        private void Button_OnClick(object? sender, RoutedEventArgs e)
        {
            Hotkey = null;
            FocusManager.Instance?.Focus(null);

            UpdateDisplayTextBox();
        }

        #region Properties

        /// <summary>
        ///     Gets or sets the currently displayed icon as either a <see cref="MaterialIconKind" /> or an <see cref="Uri" />
        ///     pointing to an SVG
        /// </summary>
        public static readonly StyledProperty<Hotkey?> HotkeyProperty =
            AvaloniaProperty.Register<HotkeyBox, Hotkey?>(nameof(Hotkey), defaultBindingMode: BindingMode.TwoWay, notifying: HotkeyChanging);

        /// <summary>
        /// Gets or sets the watermark of the hotkey box when it is empty.
        /// </summary>
        public static readonly StyledProperty<string?> WatermarkProperty =
            AvaloniaProperty.Register<HotkeyBox, string?>(nameof(Watermark));

        /// <summary>
        /// Gets or sets a boolean indicating whether the watermark should float above the hotkey box when it is not empty.
        /// </summary>
        public static readonly StyledProperty<bool> UseFloatingWatermarkProperty =
            AvaloniaProperty.Register<HotkeyBox, bool>(nameof(UseFloatingWatermark));

        /// <summary>
        ///     Gets or sets the currently displayed icon as either a <see cref="MaterialIconKind" /> or an <see cref="Uri" />
        ///     pointing to an SVG
        /// </summary>
        public Hotkey? Hotkey
        {
            get => GetValue(HotkeyProperty);
            set => SetValue(HotkeyProperty, value);
        }

        /// <summary>
        /// Gets or sets the watermark of the hotkey box when it is empty.
        /// </summary>
        public string? Watermark
        {
            get => GetValue(WatermarkProperty);
            set => SetValue(WatermarkProperty, value);
        }

        /// <summary>
        /// Gets or sets a boolean indicating whether the watermark should float above the hotkey box when it is not empty.
        /// </summary>
        public bool UseFloatingWatermark
        {
            get => GetValue(UseFloatingWatermarkProperty);
            set => SetValue(UseFloatingWatermarkProperty, value);
        }

        #endregion
    }
}