using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;

namespace HMI.UI
{
    public class MultiComboBoxItem : ComboBoxItem, INotifyPropertyChanged
    {
        #region ...
        public event PropertyChangedEventHandler PropertyChanged;

        protected void RaisePropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion

        private MultiComboBox parent;
        public MultiComboBoxItem(MultiComboBox parent)
        {
            this.parent = parent;
            this.DataContextChanged += MultiComboBoxItem_DataContextChanged;
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            this.PreviewMouseUp += MultiComboBoxItem_PreviewMouseUp;
            base.OnMouseMove(e);
        }

        protected override void OnMouseLeave(MouseEventArgs e)
        {
            this.PreviewMouseUp -= MultiComboBoxItem_PreviewMouseUp;
            base.OnMouseLeave(e);
        }

        protected override void OnLostFocus(RoutedEventArgs e)
        {
            this.PreviewMouseUp -= MultiComboBoxItem_PreviewMouseUp;
            base.OnLostFocus(e);
        }

        private void MultiComboBoxItem_PreviewMouseUp(object sender, MouseButtonEventArgs e)
        {
            if (DataContext is MultiComboBoxData data)
            {
                data.IsChecked = !data.IsChecked;
                e.Handled = true;
            }
        }

        private void MultiComboBoxItem_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (e.OldValue != null && e.OldValue is MultiComboBoxData oldData)
            {
                oldData.IsCheckedChanged -= DataIsExpandedChange;
            }
            if (DataContext != null && DataContext is MultiComboBoxData newData)
            {
                newData.IsCheckedChanged += DataIsExpandedChange;
            }
        }

        private void DataIsExpandedChange(object sender, bool IsExpanded)
        {
            parent.Item_IsCheckedChanged((MultiComboBoxData)sender, this, IsExpanded);
        }
    }

    public class MultiComboBoxDataConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is IEnumerable<object> items)
            {
                return items.Select(item => new MultiComboBoxData(item, "DisplayName", "DataValue")).ToList();
            }
            return null;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return value;
        }
    }

    public class MultiComboBoxData : INotifyPropertyChanged
    {
        #region ...
        public event PropertyChangedEventHandler PropertyChanged;

        protected void RaisePropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion

        public event EventHandler<bool> IsCheckedChanged;

        private bool isChecked;

        public bool IsChecked
        {
            get { return isChecked; }
            set
            {
                isChecked = value;
                RaisePropertyChanged("IsChecked");
                IsCheckedChanged?.Invoke(this, value);
            }
        }
        public string DisplayName
        {
            get => showName?.GetValue(Data).ToString();
        }

        public string DataValue
        {
            get => valueName?.GetValue(Data).ToString();
        }

        private PropertyInfo showName;
        private PropertyInfo valueName;

        public MultiComboBoxData(object data, string showName, string valueName)
        {
            this.Data = data;
            this.showName = data.GetType().GetProperty(showName);
            this.valueName = data.GetType().GetProperty(valueName);
        }

        public object Data { get; private set; }
    }

    /// <summary>
    /// MultiCombox.xaml 的交互逻辑
    /// </summary>
    public partial class MultiComboBox : ComboBox
    {
        protected override DependencyObject GetContainerForItemOverride()
        {
            var item = new MultiComboBoxItem(this);
            return item;
        }

        [Bindable(true)]
        [Category("Appearance")]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        [Localizability(LocalizationCategory.NeverLocalize)]
        public object SelectedValues
        {
            get
            {
                return GetValue(SelectedValuesProperty);
            }
            set
            {
                SetValue(SelectedValuesProperty, value);
            }
        }

        public static readonly DependencyProperty SelectedValuesProperty =
            DependencyProperty.RegisterAttached("SelectedValues", typeof(object), typeof(MultiComboBox),
                new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));


        public void Item_IsCheckedChanged(MultiComboBoxData data, MultiComboBoxItem item, bool isChecked)
        {
            var selectedValues = SelectedValues?.ToString() ?? "";
            var showNames = this.Text?.ToString() ?? "";
            List<string> values = string.IsNullOrEmpty(selectedValues) ? new List<string>() : selectedValues.Split(',').ToList();
            List<string> names = string.IsNullOrEmpty(showNames) ? new List<string>() : showNames.Split(',').ToList();
            if (isChecked)
            {
                values.Add(data.DataValue);
                names.Add(data.DisplayName);
            }
            else
            {
                values.Remove(data.DataValue);
                names.Remove(data.DisplayName);
            }
            Text = string.Join(",", names);
            SelectedValues = string.Join(",", values);
        }
    }
}