namespace Person
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        

        private void Form1_Load(object sender, EventArgs e)
        {

            PopulateTreeView();
        }

        void PopulateTreeView()
        {

            SqlConnection conn = new SqlConnection(@"Data Source=sqlppo;Initial Catalog=Person;Persist Security Info=True;User ID=sa;Password=");
            SqlCommand sqlQuery = new SqlCommand("select uprav, id_upr from dbo.department where rvdk_num='00'", conn);
            DataTable resultSet = new DataTable();
            DataTable product_table = new DataTable();
            conn.Open();
            SqlDataReader reader = sqlQuery.ExecuteReader();
            TreeNode[] children;
            TreeNode nodechild;
            TreeNode NewNode;
            int i = 0;


            resultSet.Load(reader);

            if (resultSet.Rows.Count > 0)
            {
                foreach (DataRow row in resultSet.Rows)
                {


                    SqlParameter param = new SqlParameter("id_upr", row[1].ToString());
                    sqlQuery = new SqlCommand("select fio from personnel where id_upr = @id_upr", conn);
                    sqlQuery.Parameters.Add(param);
                    reader = sqlQuery.ExecuteReader();

                    product_table.Load(reader);


                    children = new TreeNode[product_table.Rows.Count];

                    foreach (DataRow prod_row in product_table.Rows)
                    {
                        nodechild = new TreeNode("uprav");
                        nodechild.Text = prod_row[0].ToString();
                        children[i] = nodechild;
                        i++;
                    }

                    NewNode = new TreeNode(row[0].ToString(), children);
                    NewNode.Name = "fio";
                    treeView1.Nodes.Add(NewNode);
                    reader.Close();
                    i = 0;
                    product_table.Rows.Clear();

                }
            }
            conn.Close();
        }

        private TreeNode GetHoveringNode(int screen_x, int screen_y)
        {
            Point pt = treeView1.PointToClient(new Point(screen_x, screen_y));
            TreeViewHitTestInfo hitInfo = treeView1.HitTest(pt);
            return hitInfo.Node;
        }

        private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
        {
            treeView1.DoDragDrop(e.Item, DragDropEffects.All);
        }

        private void treeView1_DragOver(object sender, DragEventArgs e)
        {
            TreeNode hoveringNode = GetHoveringNode(e.X, e.Y);
            TreeNode draggingNode = e.Data.GetData(typeof(TreeNode)) as TreeNode;
            if (hoveringNode != null && hoveringNode != draggingNode && draggingNode != hoveringNode.Parent)
            {
                e.Effect = DragDropEffects.Move;
                hoveringNode.TreeView.SelectedNode = hoveringNode;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }

        private void treeView1_DragDrop(object sender, DragEventArgs e)
        {
            if (e.Effect == DragDropEffects.Move) 
            {
                TreeNode hoveringNode = GetHoveringNode(e.X, e.Y);
                if (hoveringNode != null) 
                {
                    TreeNode draggingNode = e.Data.GetData(typeof(TreeNode)) as TreeNode;
                    if (draggingNode != null) 
                    {
                        if (draggingNode.Level == hoveringNode.Level)
                        {
                            if (draggingNode.Level != 0)
                            {
                                draggingNode.Remove();
                                hoveringNode.Parent.Nodes.Insert(hoveringNode.Index + 1, draggingNode);
                            }
                            if (draggingNode.Level == 0)
                            {
                                draggingNode.Remove();
                                treeView1.Nodes.Insert(hoveringNode.Index + 1, draggingNode);
                            }


                        }           
                        if (draggingNode.Level > hoveringNode.Level)
                        {
                            draggingNode.Remove();
                            hoveringNode.Nodes.Insert(0, draggingNode);

                        }

                    }
                }
            }
        }  
    }
}