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

namespace Wood.Util
{
    public static class CommonHelper
    {
        public static Guid NewGuid
        {
            get
            {
                return Guid.NewGuid();
            }
        }

        public static string NewGuidStr
        {
            get
            {
                return Guid.NewGuid().ToString();
            }
        }

        public static DateTime CurrentTime
        {
            get
            {
                return DateTime.Now;
            }
        }

        public static string CurrentTimeStr
        {
            get
            {
                DateTime dt = CurrentTime;
                return dt.ToString("yyyy-MM-dd HH:mm:ss");
            }
        }

        public static string CurrentMachineName
        {
            get
            {
                return Environment.MachineName;
            }
        }

        public static string UserName
        {
            get
            {
                return "Admin";
            }
        }
    }

    /// <summary>
    /// Expression动态拼接+泛型缓存
    /// </summary>
    /// <typeparam name="TSource"></typeparam>
    /// <typeparam name="TTarget"></typeparam>
    public class EntityMapper<TSource, TTarget>//Mapper`2
    {
        private static Func<TSource, TTarget> _FUNC = null;
        static EntityMapper()
        {
            ParameterExpression parameterExpression = Expression.Parameter(typeof(TSource), "p");
            List<MemberBinding> memberBindingList = new List<MemberBinding>();
            foreach (var item in typeof(TTarget).GetProperties())
            {
                MemberExpression property = Expression.Property(parameterExpression, typeof(TSource).GetProperty(item.Name));
                MemberBinding memberBinding = Expression.Bind(item, property);
                memberBindingList.Add(memberBinding);
            }
            foreach (var item in typeof(TTarget).GetFields())
            {
                MemberExpression property = Expression.Field(parameterExpression, typeof(TSource).GetField(item.Name));
                MemberBinding memberBinding = Expression.Bind(item, property);
                memberBindingList.Add(memberBinding);
            }
            MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(TTarget)), memberBindingList.ToArray());
            Expression<Func<TSource, TTarget>> lambda = Expression.Lambda<Func<TSource, TTarget>>(memberInitExpression, new ParameterExpression[]
            {
                    parameterExpression
            });
            _FUNC = lambda.Compile();//拼装是一次性的
        }
        public static TTarget Trans(TSource tSource)
        {
            return _FUNC(tSource);
        }
    }


    /// <summary>
    /// 反射实现Mapper
    /// </summary>
    public class EntityMapper
    {
        public static void Trans<TSource, TTarget>(TSource tSource, TTarget tTarget, string excludeMembers = "")
        {
            string[] excludeMemberArr = excludeMembers.Split(",").Select(itm => itm.Trim()).ToArray();

            foreach (var itemOut in tTarget.GetType().GetProperties())
            {
                if (excludeMemberArr.Contains(itemOut.Name))
                {
                    continue;
                }
                var propIn = tSource.GetType().GetProperty(itemOut.Name);
                itemOut.SetValue(tTarget, propIn.GetValue(tSource, null), null);
            }

            foreach (var itemOut in tTarget.GetType().GetFields())
            {
                if (excludeMemberArr.Contains(itemOut.Name))
                {
                    continue;
                }
                var fieldIn = tSource.GetType().GetField(itemOut.Name);
                itemOut.SetValue(tTarget, fieldIn.GetValue(tSource));
            }
        }
    }
}