using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;
using System.Data.Common;
using System.Data;
using System.Runtime.Serialization.Json;
using System.Text.RegularExpressions;
using System.IO;

namespace SocketChat.Client
{
    public class JsonHelper
    {
        /////////////////////////////////////////Newtonsoft.Json

        #region Newtonsoft-对象转json序列化
        /// <summary>
        /// Newtonsoft-对象转json序列化
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="t"></param>
        /// <returns></returns>
        public static string ObjectToJson<T>(T t)
        {
            string jsonStr = "";
            try
            {
                jsonStr = JsonConvert.SerializeObject(t);
            }
            catch
            {
                jsonStr = "";
            }
            return jsonStr;
        }
        #endregion

        #region Newtonsoft-json转对象反序列化
        /// <summary>
        /// Newtonsoft-json转对象反序列化
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="jsonStr"></param>
        /// <returns></returns>
        public static T JsonToObject<T>(string jsonStr)
        {
            T obj = default(T);
            try
            {
                //JObject jobject = JObject.Parse(jsonStr);
                //obj = jobject.ToObject<T>();
                obj = JsonConvert.DeserializeObject<T>(jsonStr);
            }
            catch (Exception e)
            {
                obj = default(T);
            }
            return obj;
        }
        #endregion

        #region Newtonsoft-集合转json序列化
        /// <summary>
        /// Newtonsoft-集合转json序列化
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obs"></param>
        /// <returns></returns>
        public static string ListToJson<T>(List<T> obs)
        {
            string jsonStr = "";
            try
            {
                jsonStr = JsonConvert.SerializeObject(obs);
            }
            catch
            {
                jsonStr = "";
            }
            return jsonStr;
        }
        #endregion

        #region Newtonsoft-json转集合反序列化
        /// <summary>
        /// Newtonsoft-json转集合反序列化
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="t"></param>
        /// <param name="jsonStr"></param>
        /// <returns></returns>
        public static List<T> JsonToList<T>(string jsonStr)
        {
            List<T> obs = new List<T>();
            try
            {
                obs = JsonConvert.DeserializeObject<List<T>>(jsonStr);
            }
            catch
            {
                obs = new List<T>();
            }
            return obs;
        }
        #endregion

        /////////////////////////////////////////DataSet、Datatable、DataReader

        #region  DataSet转换为Json
        /// <summary> 
        /// DataSet转换为Json 
        /// </summary> 
        /// <param name="dataSet">DataSet对象</param> 
        /// <returns>Json字符串</returns> 
        public static string DataSetToJson(DataSet dataSet)
        {
            string jsonString = "{";
            foreach (DataTable table in dataSet.Tables)
            {
                jsonString += "\"" + table.TableName + "\":" + DatatableToJson(table) + ",";
            }
            jsonString = jsonString.TrimEnd(',');
            return jsonString + "}";
        }
        #endregion

        #region Datatable转换为Json
        /// <summary> 
        /// Datatable转换为Json 
        /// </summary> 
        /// <param name="table">Datatable对象</param> 
        /// <returns>Json字符串</returns> 
        public static string DatatableToJson(DataTable dt)
        {
            StringBuilder jsonString = new StringBuilder();
            jsonString.Append("[");
            DataRowCollection drc = dt.Rows;
            for (int i = 0; i < drc.Count; i++)
            {
                jsonString.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    string strKey = dt.Columns[j].ColumnName;
                    string strValue = drc[i][j].ToString();
                    Type type = dt.Columns[j].DataType;
                    jsonString.Append("\"" + strKey + "\":");
                    strValue = StringFormat(strValue, type);
                    if (j < dt.Columns.Count - 1)
                    {
                        jsonString.Append(strValue + ",");
                    }
                    else
                    {
                        jsonString.Append(strValue);
                    }
                }
                jsonString.Append("},");
            }
            jsonString.Remove(jsonString.Length - 1, 1);
            jsonString.Append("]");
            return jsonString.ToString();
        }

        /// <summary>
        /// DataTable转换为Json 
        /// </summary>
        public static string DatatableToJson(DataTable dt, string jsonName)
        {
            StringBuilder Json = new StringBuilder();
            if (string.IsNullOrEmpty(jsonName)) jsonName = dt.TableName;
            Json.Append("{\"" + jsonName + "\":[");
            if (dt.Rows.Count > 0)
            {
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    Json.Append("{");
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        Type type = dt.Rows[i][j].GetType();
                        Json.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + StringFormat(dt.Rows[i][j].ToString(), type));
                        if (j < dt.Columns.Count - 1)
                        {
                            Json.Append(",");
                        }
                    }
                    Json.Append("}");
                    if (i < dt.Rows.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
            }
            Json.Append("]}");
            return Json.ToString();
        }
        #endregion

        #region DataReader转换为Json
        /// <summary> 
        /// DataReader转换为Json 
        /// </summary> 
        /// <param name="dataReader">DataReader对象</param> 
        /// <returns>Json字符串</returns> 
        public static string DataReaderToJson(DbDataReader dataReader)
        {
            StringBuilder jsonString = new StringBuilder();
            jsonString.Append("[");
            while (dataReader.Read())
            {
                jsonString.Append("{");
                for (int i = 0; i < dataReader.FieldCount; i++)
                {
                    Type type = dataReader.GetFieldType(i);
                    string strKey = dataReader.GetName(i);
                    string strValue = dataReader[i].ToString();
                    jsonString.Append("\"" + strKey + "\":");
                    strValue = StringFormat(strValue, type);
                    if (i < dataReader.FieldCount - 1)
                    {
                        jsonString.Append(strValue + ",");
                    }
                    else
                    {
                        jsonString.Append(strValue);
                    }
                }
                jsonString.Append("},");
            }
            dataReader.Close();
            jsonString.Remove(jsonString.Length - 1, 1);
            jsonString.Append("]");
            return jsonString.ToString();
        }
        #endregion

        #region 私有方法
        /// <summary>
        /// 过滤特殊字符
        /// </summary>
        private static string String2Json(String s)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < s.Length; i++)
            {
                char c = s.ToCharArray()[i];
                switch (c)
                {
                    case '\"':
                        sb.Append("\\\""); break;
                    case '\\':
                        sb.Append("\\\\"); break;
                    case '/':
                        sb.Append("\\/"); break;
                    case '\b':
                        sb.Append("\\b"); break;
                    case '\f':
                        sb.Append("\\f"); break;
                    case '\n':
                        sb.Append("\\n"); break;
                    case '\r':
                        sb.Append("\\r"); break;
                    case '\t':
                        sb.Append("\\t"); break;
                    default:
                        sb.Append(c); break;
                }
            }
            return sb.ToString();
        }

        /// <summary>
        /// 格式化字符型、日期型、布尔型
        /// </summary>
        private static string StringFormat(string str, Type type)
        {
            if (type == typeof(string))
            {
                str = String2Json(str);
                str = "\"" + str + "\"";
            }
            else if (type == typeof(DateTime))
            {
                str = "\"" + str + "\"";
            }
            else if (type == typeof(bool))
            {
                str = str.ToLower();
            }
            else if (type != typeof(string) && string.IsNullOrEmpty(str))
            {
                str = "\"" + str + "\"";
            }
            return str;
        }
        #endregion

        /////////////////////////////////////////微软自带json解析类

        #region 微软-JSON序列化
        /// <summary>
        /// JSON序列化
        /// </summary>
        public static string JsonSerializer<T>(T t)
        {
            string jsonString = "";
            try
            {
                DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
                MemoryStream ms = new MemoryStream();
                ser.WriteObject(ms, t);
                jsonString = Encoding.UTF8.GetString(ms.ToArray());
                ms.Close();
                //替换Json的Date字符串
                string p = @"\\/Date\((\d+)\+\d+\)\\/";
                MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
                Regex reg = new Regex(p);
                jsonString = reg.Replace(jsonString, matchEvaluator);
            }
            catch
            {
                jsonString = "";
            }
            return jsonString;
        }
        #endregion

        #region 微软-JSON反序列化
        /// <summary>
        /// JSON反序列化
        /// </summary>
        public static T JsonDeserialize<T>(string jsonString)
        {
            T obj = default(T);
            try
            {
                //将"yyyy-MM-dd HH:mm:ss"格式的字符串转为"\/Date(1294499956278+0800)\/"格式
                string p = @"\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}";
                MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);
                Regex reg = new Regex(p);
                jsonString = reg.Replace(jsonString, matchEvaluator);
                DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
                MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
                obj = (T)ser.ReadObject(ms);
            }
            catch
            {
                obj = default(T);
            }
            return obj;
        }
        #endregion

        #region 将Json序列化的时间由/Date(1294499956278+0800)转为字符串
        /// <summary>
        /// 将Json序列化的时间由/Date(1294499956278+0800)转为字符串
        /// </summary>
        private static string ConvertJsonDateToDateString(Match m)
        {
            string result = string.Empty;
            DateTime dt = new DateTime(1970, 1, 1);
            dt = dt.AddMilliseconds(long.Parse(m.Groups[1].Value));
            dt = dt.ToLocalTime();
            result = dt.ToString("yyyy-MM-dd HH:mm:ss");
            return result;
        }
        #endregion

        #region 将时间字符串转为Json时间
        /// <summary>
        /// 将时间字符串转为Json时间
        /// </summary>
        private static string ConvertDateStringToJsonDate(Match m)
        {
            string result = string.Empty;
            DateTime dt = DateTime.Parse(m.Groups[0].Value);
            dt = dt.ToUniversalTime();
            TimeSpan ts = dt - DateTime.Parse("1970-01-01");
            result = string.Format("\\/Date({0}+0800)\\/", ts.TotalMilliseconds);
            return result;
        }
        #endregion
    }
}