using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace WMS.Util
{
    public class DataTableToList<T> where T : new()
    {
        public static IList<T> ConvertToModel(DataTable dt)
        {
            // 定义集合    
            IList<T> ts = new List<T>();

            // 获得此模型的类型   
            Type type = typeof(T);
            string tempName = "";

            foreach (DataRow dr in dt.Rows)
            {
                T t = new T();
                // 获得此模型的公共属性      
                PropertyInfo[] propertys = t.GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    tempName = pi.Name;  // 检查DataTable是否包含此列    

                    if (dt.Columns.Contains(tempName))
                    {
                        // 判断此属性是否有Setter      
                        if (!pi.CanWrite) continue;

                        object value = dr[tempName];
                        if (value != DBNull.Value)
                            pi.SetValue(t, value, null);
                    }
                }
                ts.Add(t);
            }
            return ts;
        }
    }


    public static class DataTableExtension
    {
        public static List<T> ToList<T>(this DataTable dt, IRowMapper<T> rowMapper)
        {
            if (dt == null || dt.Rows.Count == 0)
            {
                return null;
            }

            List<T> entites = new List<T>();

            foreach (DataRow dr in dt.Rows)
            {
                var t = rowMapper.MapRow(dr);

                entites.Add(t);
            }
            return entites;
        }


        /// <summary>
        ///   可以直接使用newtonsoft进行序列化
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dt"></param>
        /// <param name="rowMapper"></param>
        /// <returns></returns>
        public static string ToJson<T>(this DataTable dt, IRowMapper<T> rowMapper)
        {
            if (dt == null || dt.Rows.Count == 0)
            {
                return null;
            }

            StringBuilder strBuilder = new StringBuilder("[");

            foreach (DataRow dr in dt.Rows)
            {
                var t = rowMapper.MapRow(dr);

                strBuilder.Append(t + ",");
            }
            strBuilder.Remove(strBuilder.Length - 1, 1);
            strBuilder.Append("]");


            return strBuilder.ToString();
        }
    }
    public class ColumnAttributeMapper<T> : IRowMapper<T>
    {
        private  Dictionary<string, Dictionary<string, string>> ColumnPropertyMapper = new Dictionary<string, Dictionary<string, string>>();

        public ColumnAttributeMapper()
        {
            if (!ColumnPropertyMapper.ContainsKey(typeof(T).Name))
            {
                Dictionary<string, string> dict = new Dictionary<string, string>();

                var props = typeof(T).GetProperties();

                foreach (var prop in props)
                {
                    var attribute = prop.GetCustomAttributes(true).OfType<ColumnAttribute>().FirstOrDefault();
                    dict.Add(attribute.Name, prop.Name);

                }
                ColumnPropertyMapper.Add(typeof(T).Name, dict);
            }

        }

        public T MapRow(DataRow dr)
        {
            T t = (T)Activator.CreateInstance(typeof(T));
            for (int i = 0; i < dr.Table.Columns.Count; i++)
            {
                if (ColumnPropertyMapper.ContainsKey(t.GetType().Name))
                {
                    var dict = ColumnPropertyMapper[t.GetType().Name];
                    var property = dict[dr.Table.Columns[i].ColumnName];

                    PropertyInfo propertyInfo = t.GetType().GetProperty(property);
                    if (propertyInfo != null && dr[i] != DBNull.Value)
                        propertyInfo.SetValue(t, dr[i], null);
                }
            }
            return t;
        }
    }
    /// <summary>
    /// 将查询结果映射为对象
    /// </summary>
    /// <typeparam name="TResult"></typeparam>
    public interface IRowMapper<out TResult>
    {
        /// <summary>
        /// When implemented by a class, returns a new TResult based on row.
        /// </summary>
        /// <param name="row"> The System.Data.IDataRecord to map.</param>
        /// <returns>The instance of TResult that is based on row.</returns>
        TResult MapRow(DataRow dr);
        /// <summary>
        /// 增加自定义转换，todo 复杂列（eee#bb）转换
        /// </summary>
        /// <param name="convert"></param>
        //void AddCustomConverter(Converter convert);
        /// <summary>
        /// 表信息，每个数据库一个
        /// </summary>
        //TablesInfo TablesInfo { get; set; }
    }
    public class ColumnConverter
    {
        public string ColumnName { get; set; }

        public string PropertyPath { get; set; }
        /// <summary>
        /// 数据库值转换为对象值
        /// </summary>
        public Func<object> Convert { get; set; }
    }

    public class JsonMapper : IRowMapper<StringBuilder>
    {
        public StringBuilder MapRow(DataRow dr)
        {
            StringBuilder strBuilder = new StringBuilder();
            StringWriter strWriter = new StringWriter(strBuilder);

            using (JsonWriter writer = new JsonTextWriter(strWriter))
            {
                writer.WriteStartObject();

                foreach (var col in dr.Table.Columns)
                {
                    var value = dr.Field<object>(col.ToString());

                    writer.WritePropertyName(col.ToString());
                    writer.WriteValue(value);
                }

                writer.WriteEndObject();

            }
            return strBuilder;

        }
    }

    public class ColumnAttribute : Attribute
    {
        public string Name { get; set; }


        public ColumnAttribute(string fieldName)
        {
            this.Name = fieldName;
        }

    }
}