using System;
using System.Collections;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Threading;

namespace Muchinfo.WPF.Controls.MarQuees
{
    public delegate void OnItemClickHander(Object sender, RoutedEventArgs e);

    /// <summary>
    /// CutOverControl.xaml 的交互逻辑
    /// </summary>
    public partial class CutOverControl : UserControl
    {
        public CutOverControl()
        {
            InitializeComponent();

            _playTimer.Interval = TimeSpan.FromSeconds(2);
            _playTimer.Tick += _playTimer_Tick;
            this.Height = this.FontFamily.LineSpacing * this.FontSize + _borderThiness;

        }

        private const double _borderThiness = 2;   //显示边框的大小
        private DispatcherTimer _playTimer = new DispatcherTimer();
        private ScrollViewer _listBoxScrollViewer; //列表的滚动条

        /// <summary>
        /// 列表的滚动条
        /// </summary>
        private ScrollViewer ListBoxScrollViewer
        {
            get
            {
                if (_listBoxScrollViewer != null)
                {
                    return _listBoxScrollViewer;
                }
                _listBoxScrollViewer = FindVisualChild<ScrollViewer>(ContentListBox);
                return _listBoxScrollViewer;
            }
        }

        /// <summary>
        /// 从父容器中查找指定类型的控件
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="parent"></param>
        /// <returns></returns>
        public T FindVisualChild<T>(DependencyObject parent) where T : DependencyObject
        {
            if (parent == null) return null;
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
            {
                var child = VisualTreeHelper.GetChild(parent, i);
                if (child != null && child is T)
                {
                    return (T)child;
                }
                T childItem = FindVisualChild<T>(child);
                if (childItem != null)
                    return childItem;
            }
            return null;
        }

        //切换另一字符串
        private void _playTimer_Tick(object sender, EventArgs e)
        {
            if (ItemsSource == null || ItemsSource.Count == 0)
            {
                _playTimer.Stop();
                return;
            }
            if (ListBoxScrollViewer == null) return;
            if (ListBoxScrollViewer.VerticalOffset >=
                (ListBoxScrollViewer.ExtentHeight -
                ListBoxScrollViewer.ViewportHeight))
            {
                ListBoxScrollViewer.ScrollToTop();
            }
            else
            {
                ListBoxScrollViewer.ScrollToVerticalOffset(ListBoxScrollViewer.VerticalOffset +
                ListBoxScrollViewer.ViewportHeight);
            }

        }

        /// <summary>
        /// 更换时间
        /// </summary>
        public TimeSpan DelayTime
        {
            get { return (TimeSpan)GetValue(DelayTimeProperty); }
            set { SetValue(DelayTimeProperty, value); }
        }

        // Using a DependencyProperty as the backing store for DelayTime.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty DelayTimeProperty =
            DependencyProperty.Register("DelayTime", typeof(TimeSpan), typeof(CutOverControl), new PropertyMetadata(TimeSpan.FromSeconds(1), OnDelayTimeChange));

        /// <summary>
        /// 显示内容
        /// </summary>
        public Object DisplayContet
        {
            get { return (Object)GetValue(DisplayContetProperty); }
            set { SetValue(DisplayContetProperty, value); }
        }

        // Using a DependencyProperty as the backing store for DisplayContet.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty DisplayContetProperty =
            DependencyProperty.Register("DisplayContet", typeof(Object), typeof(CutOverControl), new PropertyMetadata(null));

        /// <summary>
        /// 循环显示的数据源
        /// </summary>
        public IList ItemsSource
        {
            get { return (IList)GetValue(ItemsSourceProperty); }
            set { SetValue(ItemsSourceProperty, value); }
        }

        // Using a DependencyProperty as the backing store for ItemsSource.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ItemsSourceProperty =
            DependencyProperty.Register("ItemsSource", typeof(IList), typeof(CutOverControl), new PropertyMetadata(new List<Object>(), OnItemsSourceChange));

        /// <summary>
        /// 项模板
        /// </summary>
        public DataTemplate ItemTemplate
        {
            get { return (DataTemplate)GetValue(ItemTemplateProperty); }
            set { SetValue(ItemTemplateProperty, value); }
        }

        // Using a DependencyProperty as the backing store for ItemTemplate.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ItemTemplateProperty =
            DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(CutOverControl), new PropertyMetadata(null));

        //数据源改变时
        private static void OnItemsSourceChange(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var cutOver = d as CutOverControl;
            if (cutOver == null) return;
            if (e.NewValue is IList)
            {
                var listView = e.NewValue as IList;
                if (listView.Count > 0)
                {
                    cutOver._playTimer.Start();
                }
            }
        }

        /// <summary>
        /// 当更换时间改变时
        /// </summary>
        private static void OnDelayTimeChange(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var cutOver = d as CutOverControl;
            if (cutOver == null) return;
            cutOver._playTimer.Stop();
            cutOver._playTimer.Interval = cutOver.DelayTime;
            cutOver._playTimer.Start(); //重新开始
        }

        //当鼠标放在上面时停止滚动
        private void UIElement_OnMouseEnter(object sender, MouseEventArgs e)
        {
            if (_playTimer.IsEnabled)
            {
                _playTimer.Stop();
            }
        }
        //当鼠标放在离开时滚动
        private void UIElement_OnMouseLeave(object sender, MouseEventArgs e)
        {
            if (!_playTimer.IsEnabled)
            {
                _playTimer.Start();
            }
        }


        public event OnItemClickHander ItemClick = null;

        /// <summary>
        /// 选择项
        /// </summary>
        private void EventSetter_OnHandler(object sender, MouseButtonEventArgs e)
        {
            // throw new NotImplementedException();
            if (ItemClick != null)
            {
                ItemClick(sender, e);
            }
        }
    }
}