using PDF_Office.Helper;
using PDF_Office.Model.Dialog.ToolsDialogs;
using PDF_Office.ViewModels.Dialog.ToolsDialogs;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace PDF_Office.Views.Dialog.ToolsDialogs
{
    /// <summary>
    /// MergeDialog.xaml 的交互逻辑
    /// </summary>
    public partial class MergeDialog : UserControl
    {
        /// <summary>
        /// 当前显示了线段的Item
        /// </summary>
        private ListViewItem listViewItem = null;
        public MergeDialog()
        {
            InitializeComponent();
        }

        private void Delete_Click(object sender, RoutedEventArgs e)
        {
            (DataContext as MergeDialogViewModel).DeleteItem((sender as Button).DataContext as MergeObject);
        }

        private void MergeView_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                var pos = e.GetPosition(MergeView);
                HitTestResult result = VisualTreeHelper.HitTest(MergeView, pos);
                if (result == null)
                {
                    return;
                }
                var treeViewItem = CommonHelper.FindVisualParent<ListViewItem>(result.VisualHit);
                if (treeViewItem == null)
                {
                    return;
                }
                DataObject dataObj = new DataObject(treeViewItem);
                DragDrop.DoDragDrop(MergeView, dataObj, DragDropEffects.Move);
                return;
            }

        }

        private void MergeView_Drop(object sender, DragEventArgs e)
        {
            ListViewItem souredata = e.Data.GetData(typeof(ListViewItem)) as ListViewItem;
            MergeObject soureNode = souredata.DataContext as MergeObject;
            Point pos = e.GetPosition(MergeView);
            HitTestResult result = VisualTreeHelper.HitTest(MergeView, pos);
            if (result == null)
            {
                HiddenaAllLine();
                return;
            }
            ListViewItem targetitem = CommonHelper.FindVisualParent<ListViewItem>(result.VisualHit);
            if (targetitem == null)
            {
                HiddenaAllLine();
                return;
            }
            MergeObject targetNode = targetitem.DataContext as MergeObject;
            if (soureNode.Equals(targetNode))
            {
                HiddenaAllLine();
                return;
            }
           (DataContext as MergeDialogViewModel).MoveMerge(targetNode, soureNode);

            HiddenaAllLine();
        }

        private void MergeView_DragOver(object sender, DragEventArgs e)
        {
            ListViewItem sourceitem = e.Data.GetData(typeof(ListViewItem)) as ListViewItem;
            if (sourceitem == null)
            {
                return;
            }
            Point pos = e.GetPosition(MergeView);
            HitTestResult result = VisualTreeHelper.HitTest(MergeView, pos);
            if (result != null)
            {
                ListViewItem treeviewitem = CommonHelper.FindVisualParent<ListViewItem>(result.VisualHit);
                if (treeviewitem != null)
                {
                    if (listViewItem == null)
                    {
                        listViewItem = treeviewitem;
                    }
                    else if (!listViewItem.Equals(treeviewitem))
                    {
                        (listViewItem.DataContext as MergeObject).IsBackwards = false;
                        (listViewItem.DataContext as MergeObject).IsForward = false;
                        listViewItem = treeviewitem;
                    }
                    else
                    {
                        (listViewItem.DataContext as MergeObject).IsBackwards = false;
                        (listViewItem.DataContext as MergeObject).IsForward = false;
                    }
                    if (listViewItem.Equals(sourceitem))
                    {
                        return;
                    }

                    //鼠标位于上半部分显示实线，下半部分显示虚线
                    Point p = treeviewitem.TranslatePoint(new Point(0, 0), MergeView);
                    if (pos.Y < p.Y + 16)
                    {
                        (treeviewitem.DataContext as MergeObject).IsBackwards = true;
                    }
                    else
                    {
                        (treeviewitem.DataContext as MergeObject).IsForward = true;
                    }
                }
            }
        }

        private void MergeView_DragLeave(object sender, DragEventArgs e)
        {
            HiddenaAllLine();
        }

        /// <summary>
        /// 清理线条显示，以及相关缓存对象
        /// </summary>
        private void HiddenaAllLine()
        {
            if (listViewItem != null)
            {
                (listViewItem.DataContext as MergeObject).IsBackwards = false;
                (listViewItem.DataContext as MergeObject).IsForward = false;
                listViewItem = null;
            }
        }
    }
}