using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Hncore.Infrastructure.Tree
{
    public class DataNode<TData>
    {
        public DataNode(TData data)
        {
            this.Data = data;
        }

        public DataNode<TData> Parent { get; set; }
        public TData Data { get; set; }

        public List<DataNode<TData>> Children { get; set; } = new List<DataNode<TData>>();

        public bool IsLeaf { get { return this.Children.Count()==0; } }

        public void Traverse(Action<DataNode<TData>> act)
        {
            act(this);
            this.Children.ForEach(item =>
            {
                item.Traverse(act);
            });
        }

        public string GetFullPath(Func<TData, string> func, string separator = ".")
        {
            var parent = this.Parent;
            var names = new List<string> { func(this.Data) };
            while (parent != null)
            {
                names.Add(func(parent.Data));
                parent = parent.Parent;
            }
            names.Reverse();
            return string.Join(separator, names).TrimStart(separator.ToArray());
        }

        public  DataNode<TData> SortAsc<Tkey>(Func<TData, Tkey> exp)
        {
            if (this.Children.Count > 0)
            {
                Func<DataNode<TData>, Tkey> iierExp = m => exp(m.Data);
                this.Children.OrderBy(iierExp);
                this.Children.ForEach(item =>
                {
                    item.SortAsc(exp);
                });
            }
            return this;
        }  

        public DataNode<TData> SortDesc<Tkey>(Func<TData, Tkey> exp)
        {
            if (this.Children.Count > 0)
            {
                Func<DataNode<TData>, Tkey> iierExp = m => exp(m.Data);
                this.Children.OrderByDescending(iierExp);
                this.Children.ForEach(item =>
                {
                    item.SortDesc(exp);
                });
            }

            return this;
        }
    }
}