using System;
using System.Collections.Generic;
using System.Linq;

namespace Hncore.Infrastructure.Tree
{
    public class DataTree
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="topPredicate">得到第一级节点条件</param>
        /// <param name="childPredicate">得到孩子得条件</param>
        public static DataNode<TData> Load<TData>(IEnumerable<TData> datas, Func<TData, bool> topPredicate, Func<TData, TData, bool> childPredicate) where TData : new()
        {
            var root = new DataNode<TData>(new TData() { });
            if (datas == null || datas.Count() == 0)
                return root;
            var tops = datas.Where(topPredicate);

            foreach (var p in tops)
            {
                LoadChildren(datas, root, p, childPredicate);
            }
            return root;
        }
        private static void LoadChildren<TData>(IEnumerable<TData> datas,DataNode<TData> topNode, TData p, Func<TData,TData, bool> childPredicate)
        {
            var pNode = new DataNode<TData>(p);
            pNode.Parent = topNode;
            topNode.Children.Add(pNode);

            var childDatas = datas.Where(item=>childPredicate(p,item)) ;

            if (childDatas.Count() > 0)              
            {
                foreach (var childData in childDatas)
                {
                    LoadChildren(datas,pNode, childData, childPredicate);
                }
            }
        }


        public static void Traverse<TData>(DataNode<TData> rootNode, Action<DataNode<TData>> act, bool root = true)
        {
            if (root)
            {
                rootNode.Traverse(act);
            }
            else
            {
                rootNode.Children.ForEach(item =>
                {
                    item.Traverse(act);
                });
            }
        }
    }
}