using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Tiobon.Core.OPS.Tool.OPS.Tool.Helper
{
    public static class Convetdata
    {
        public static List<T> ToList<T>(this DataTable dt) where T : class, new()
        {
            Type t = typeof(T);
            PropertyInfo[] propertys = t.GetProperties();
            List<T> lst = new List<T>();
            string typeName = string.Empty;

            foreach (DataRow dr in dt.Rows)
            {
                T entity = new T();
                foreach (PropertyInfo pi in propertys)
                {
                    typeName = pi.Name;
                    if (dt.Columns.Contains(typeName))
                    {
                        if (!pi.CanWrite) continue;
                        object value = dr[typeName];
                        if (value == DBNull.Value) continue;
                        if (pi.PropertyType == typeof(string))
                        {
                            pi.SetValue(entity, value.ToString(), null);
                        }
                        else if (pi.PropertyType == typeof(int) || pi.PropertyType == typeof(int?))
                        {
                            pi.SetValue(entity, int.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(DateTime?) || pi.PropertyType == typeof(DateTime))
                        {
                            pi.SetValue(entity, DateTime.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(float))
                        {
                            pi.SetValue(entity, float.Parse(value.ToString()), null);
                        }
                        else if (pi.PropertyType == typeof(double))
                        {
                            pi.SetValue(entity, double.Parse(value.ToString()), null);
                        }
                        else
                        {
                            pi.SetValue(entity, value, null);
                        }
                    }
                }
                lst.Add(entity);
            }
            return lst;
        }



        public static void ForEach<T>(this IEnumerable<T> ien, Action<T> express)
        {
            foreach (var item in ien)
            {
                express(item);
            }

        }

        public static DataTable ToDataTable<T>(this IEnumerable<T> value) where T : class, new()
        {
            List<PropertyInfo> lstProperty = new List<PropertyInfo>();
            Type type = typeof(T);
            DataTable dt = new DataTable();
            type.GetProperties().ForEach(p =>  //ForEach扩展方法，这里使用Array.ForEach(type.GetProperties(),p=>{})也是一样
            {
                lstProperty.Add(p);
                if (p.PropertyType.IsGenericType)//是否为泛型，泛型获取不到具体的类型
                {
                    dt.Columns.Add(p.Name);
                }
                else
                {
                    dt.Columns.Add(p.Name, p.PropertyType);
                }
            });
            if (value != null)
            {
                foreach (var item in value)
                {
                    //创建一个DataRow实例
                    DataRow row = dt.NewRow();
                    lstProperty.ForEach(p =>
                    {
                        row[p.Name] = p.GetValue(item, null);
                    });
                    dt.Rows.Add(row);
                }
            }
            return dt;
        }

    }
}