using System;
using System.Collections;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Input;
using System.Linq;
using System.Windows.Media;
using System.Windows.Threading;
using Tango.Core.ExtensionMethods;

namespace Tango.SharedUI.Controls
{
    public class SearchComboBox : ComboBox
    {
        private TextBox _textBox;
        private ListBox _listBox;
        private ICollectionView _view;

        public bool IsOpened
        {
            get { return (bool)GetValue(IsOpenedProperty); }
            set { SetValue(IsOpenedProperty, value); }
        }
        public static readonly DependencyProperty IsOpenedProperty =
            DependencyProperty.Register("IsOpened", typeof(bool), typeof(SearchComboBox), new PropertyMetadata(false, (d, e) => (d as SearchComboBox).OnIsOpenedChanged()));

        public String SearchProperty
        {
            get { return (String)GetValue(SearchPropertyProperty); }
            set { SetValue(SearchPropertyProperty, value); }
        }
        public static readonly DependencyProperty SearchPropertyProperty =
            DependencyProperty.Register("SearchProperty", typeof(String), typeof(SearchComboBox), new PropertyMetadata(null));

        public String SearchFilter
        {
            get { return (String)GetValue(SearchFilterProperty); }
            set { SetValue(SearchFilterProperty, value); }
        }
        public static readonly DependencyProperty SearchFilterProperty =
            DependencyProperty.Register("SearchFilter", typeof(String), typeof(SearchComboBox), new PropertyMetadata(null, (d, e) => (d as SearchComboBox).OnFilterChanged()));

        public IEnumerable ListItemsSource
        {
            get { return (IEnumerable)GetValue(ListItemsSourceProperty); }
            set { SetValue(ListItemsSourceProperty, value); }
        }
        public static readonly DependencyProperty ListItemsSourceProperty =
            DependencyProperty.Register("ListItemsSource", typeof(IEnumerable), typeof(SearchComboBox), new PropertyMetadata(null));


        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();
            _textBox = GetTemplateChild("txt") as TextBox;
            _listBox = GetTemplateChild("list") as ListBox;
            _textBox.PreviewKeyDown += _textBox_KeyDown;
            _listBox.PreviewKeyDown += _listBox_PreviewKeyDown;

            _listBox.PreviewMouseLeftButtonUp += _listBox_PreviewMouseLeftButtonUp;

            KeyboardNavigation.SetDirectionalNavigation(this, KeyboardNavigationMode.Once);
        }

        private void _listBox_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Return)
            {
                IsOpened = false;
                SelectedItem = _listBox.SelectedItem;

                if (SelectedValuePath.IsNotNullOrEmpty() && SelectedItem != null)
                {
                    SelectedValue = SelectedItem.GetPropertyValueByPath(SelectedValuePath);
                }
            }
            else if (e.Key == Key.Up && _listBox.SelectedIndex == 0)
            {
                _textBox.Focus();
                Keyboard.Focus(_textBox);
            }
        }

        private void _textBox_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Down)
            {
                e.Handled = true;
                FocusList();
            }
        }

        private void FocusList()
        {
            if (!String.IsNullOrWhiteSpace(SearchFilter))
            {
                _listBox.SelectedIndex = 0;
            }

            Keyboard.Focus(_listBox);

            if (_listBox.SelectedIndex != -1)
            {
                var container = _listBox.ItemContainerGenerator.ContainerFromIndex(_listBox.SelectedIndex) as UIElement;
                if (container != null)
                {
                    container.Focus();
                    Keyboard.Focus(container);
                }
            }

            _listBox.ScrollIntoView(_listBox.SelectedItem);
        }

        private void _listBox_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            if (_listBox.SelectedItem != null)
            {
                if (SelectedItem != _listBox.SelectedItem)
                {
                    IsOpened = false;
                    SelectedItem = _listBox.SelectedItem;

                    if (SelectedValuePath.IsNotNullOrEmpty() && SelectedItem != null)
                    {
                        SelectedValue = SelectedItem.GetPropertyValueByPath(SelectedValuePath);
                    }
                }
            }
        }

        private async void OnIsOpenedChanged()
        {
            if (IsOpened)
            {
                SearchFilter = String.Empty;
                _listBox.SelectedItem = SelectedItem;
                _listBox.ScrollIntoView(_listBox.SelectedItem);
                await Task.Delay(100);
                _textBox.Focus();
                Keyboard.Focus(_textBox);
            }
        }

        protected override void OnItemsSourceChanged(IEnumerable oldValue, IEnumerable newValue)
        {
            base.OnItemsSourceChanged(oldValue, newValue);

            if (ItemsSource != null)
            {
                ListItemsSource = ItemsSource.Cast<Object>().ToList();

                _view = CollectionViewSource.GetDefaultView(ListItemsSource);
                _view.Filter = (x) =>
                {
                    if (String.IsNullOrWhiteSpace(SearchFilter) || SearchFilter == null) return true;

                    if (x != null)
                    {
                        if (!String.IsNullOrWhiteSpace(SearchProperty))
                        {
                            var prop = x.GetType().GetProperty(SearchProperty, System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);
                            if (prop != null)
                            {
                                String propValue = prop.GetValue(x).ToString();
                                return propValue.ToLower().Contains(SearchFilter.ToLower());
                            }
                        }

                        return x.ToStringSafe().ToLower().Contains(SearchFilter.ToLower());
                    }

                    return false;
                };
            }
        }

        private void OnFilterChanged()
        {
            _view?.Refresh();

            if (_listBox != null && _listBox.Items.Count > 0)
            {
                _listBox.ScrollIntoView(_listBox.Items[0]);
            }
        }

        protected override void OnPreviewKeyDown(KeyEventArgs e)
        {
            //base.OnPreviewKeyDown(e);
            e.Handled = false;
        }

        protected override void OnPreviewKeyUp(KeyEventArgs e)
        {
            //base.OnPreviewKeyUp(e);
            e.Handled = false;
        }

        protected override void OnKeyDown(KeyEventArgs e)
        {
            //base.OnKeyDown(e);
            e.Handled = false;
        }

        protected override void OnKeyUp(KeyEventArgs e)
        {
            //base.OnKeyUp(e);
            e.Handled = false;
        }

        protected override void OnPreviewMouseWheel(MouseWheelEventArgs e)
        {
            e.Handled = true;

            if (!_listBox.IsFocused)
            {
                FocusList();
            }

            if (e.Delta > 0)
            {
                _listBox.RaiseEvent(
                new KeyEventArgs(
                    System.Windows.Input.Keyboard.PrimaryDevice,
                    PresentationSource.FromVisual(_listBox), 0, Key.Up)
                { RoutedEvent = System.Windows.Input.Keyboard.KeyDownEvent });

                _listBox.RaiseEvent(
                    new KeyEventArgs(
                        System.Windows.Input.Keyboard.PrimaryDevice,
                        PresentationSource.FromVisual(_listBox), 0, Key.Up)
                    { RoutedEvent = System.Windows.Input.Keyboard.KeyUpEvent });
            }
            else
            {
                _listBox.RaiseEvent(
                new KeyEventArgs(
                    System.Windows.Input.Keyboard.PrimaryDevice,
                    PresentationSource.FromVisual(_listBox), 0, Key.Down)
                { RoutedEvent = System.Windows.Input.Keyboard.KeyDownEvent });

                _listBox.RaiseEvent(
                    new KeyEventArgs(
                        System.Windows.Input.Keyboard.PrimaryDevice,
                        PresentationSource.FromVisual(_listBox), 0, Key.Down)
                    { RoutedEvent = System.Windows.Input.Keyboard.KeyUpEvent });
            }
            //base.OnPreviewMouseWheel(e);
        }

        protected override void OnMouseWheel(MouseWheelEventArgs e)
        {
            e.Handled = true;
            //base.OnMouseWheel(e);
        }

        static SearchComboBox()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(SearchComboBox), new FrameworkPropertyMetadata(typeof(SearchComboBox)));
        }
    }
}