using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;

namespace Bowin.Web.Controls.Mvc
{
    public static class CheckListTreeExtensions
    {
        public static MvcHtmlString CheckListTree(this HtmlHelper htmlHelper,
            ListTreeOptions listTreeOptions)
        {
            var topItems = listTreeOptions.ItemList.Where(x => x.ParentValue == null).ToList();

            if (listTreeOptions == null)
            {
                listTreeOptions = new ListTreeOptions();
            }

            if((listTreeOptions.ItemName ?? "") == "")
            {
                listTreeOptions.ItemName = "checkBoxTreeList" + Guid.NewGuid().ToString();
            }
            if ((listTreeOptions.LeafWidth ?? 0) < 1)
            {
                listTreeOptions.LeafWidth = 1;
            }
            StringBuilder html = new StringBuilder();

            for (int i = 0; i < topItems.Count; i ++ )
            {
                string myID = listTreeOptions.ItemName +Guid.NewGuid()+ i;
                int level = 0;
                html.AppendFormat("<div><input id='{4}' onclick='checkBranch();' type='checkbox' name='{2}'{3} value='{0}'/>{1}</div>",
                    topItems[i].Value,
                    topItems[i].Text,
                    listTreeOptions.ItemName,
                    ((listTreeOptions.SelectedValues.Contains(topItems[i].Value)) ? " checked" : ""),
                    myID);

                AddSubItems(html, listTreeOptions, myID, topItems[i], level);
            }

            return MvcHtmlString.Create(html.ToString());
        }

        private static void AddSubItems(StringBuilder html, ListTreeOptions listTreeOptions, string parentID, ListTreeItem item, int level)
        {
            var curItems = listTreeOptions.ItemList.Where(x => (x.ParentValue != null) ? x.ParentValue.Equals(item.Value) : false);
            var leafItems = curItems.Where(x => !listTreeOptions.ItemList.Exists(y => (y.ParentValue != null) ? y.ParentValue.Equals(x.Value) : false)).ToList();
            var branchItems = curItems.Where(x => !leafItems.Contains(x)).ToList();
            var nowLevel = level + 1;
            int rowCount = Convert.ToInt32(Math.Ceiling(((double)leafItems.Count()) / listTreeOptions.LeafWidth.Value));

            for (int i = 0; i < rowCount; i ++)
            {
                html.Append("<div>");
                for (int k = 0; k < nowLevel; k++)
                {
                    html.Append("&nbsp;&nbsp;");
                }

                for (int j = 0; j < listTreeOptions.LeafWidth; j++)
                {
                    var curIndex = i * listTreeOptions.LeafWidth.Value + j;

                    if (leafItems.Count > curIndex)
                    {
                        string myID = parentID + "l" + curIndex;

                        html.AppendFormat("<input id='{4}' type='checkbox' name='{2}'{3} value='{0}'/>{1}",
                            leafItems[curIndex].Value,
                            leafItems[curIndex].Text,
                            listTreeOptions.ItemName,
                            ((listTreeOptions.SelectedValues.Contains(leafItems[curIndex].Value)) ? " checked" : ""),
                            myID);
                    }

                    html.Append("&nbsp;");
                }
                html.Append("</div>");
            }

            for (int i = 0; i < branchItems.Count; i ++ )
            {
                string myID = parentID + i;

                html.Append("<div>");
                for (int j = 0; j < nowLevel; j++)
                {
                    html.Append("&nbsp;&nbsp;");
                }
                html.AppendFormat("<input id='{4}' onclick='checkBranch();' type='checkbox' name='{2}'{3} value='{0}'/>{1}",
                    branchItems[i].Value,
                    branchItems[i].Text,
                    listTreeOptions.ItemName,
                    ((listTreeOptions.SelectedValues.Contains(branchItems[i].Value)) ? " checked" : ""),
                    myID);
                html.Append("</div>");

                AddSubItems(html, listTreeOptions, myID, branchItems[i], nowLevel);
            }
        }
    }
}