using Newtonsoft.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Web.Script.Serialization;

namespace Dao
{
    public class JsonHelper
    {
        public static Hashtable Json2Hashtable(string json)
        {
            return JsonConvert.DeserializeObject<Hashtable>(json);
        }

        public static List<T> Json2ListHashtable<T>(string json)
        {
            return JsonConvert.DeserializeObject<List<T>>(json);
        }

        public string toSimpleJson(DataSet ds)
        {
            Newtonsoft.Json.Converters.IsoDateTimeConverter timeConverter = new Newtonsoft.Json.Converters.IsoDateTimeConverter();
            timeConverter.DateTimeFormat = "yyyy'-'MM'-'dd' 'HH':'mm':'ss'.'fff";
            string result = JsonConvert.SerializeObject(ds, timeConverter);

            return result;
        }

        /// <summary>
        /// 将字典类型序列化为json字符串
        /// </summary>
        /// <typeparam name="TKey">字典key</typeparam>
        /// <typeparam name="TValue">字典value</typeparam>
        /// <param name="dict">要序列化的字典数据</param>
        /// <returns>json字符串</returns>
        public static string SerializeDictionaryToJsonString<TKey, TValue>(Dictionary<TKey, TValue> dict)
        {
            if (dict.Count == 0)
                return "";

            string jsonStr = JsonConvert.SerializeObject(dict);
            return jsonStr;
        }

        /// <summary>
        /// 将json字符串反序列化为字典类型
        /// </summary>
        /// <typeparam name="TKey">字典key</typeparam>
        /// <typeparam name="TValue">字典value</typeparam>
        /// <param name="jsonStr">json字符串</param>
        /// <returns>字典数据</returns>
        public static Dictionary<TKey, TValue> DeserializeStringToDictionary<TKey, TValue>(string jsonStr)
        {
            if (string.IsNullOrEmpty(jsonStr))
                return new Dictionary<TKey, TValue>();

            Dictionary<TKey, TValue> jsonDict = JsonConvert.DeserializeObject<Dictionary<TKey, TValue>>(jsonStr);

            return jsonDict;

        }

        /// <summary>
        /// 导出Excel
        /// </summary>
        /// <param name="table"></param>
        /// <param name="file"></param>
        public static void dataTableToCsv(DataTable table, string file)
        {
            string title = "";
            FileStream fs = new FileStream(file, FileMode.OpenOrCreate);
            StreamWriter sw = new StreamWriter(new BufferedStream(fs), System.Text.Encoding.Default);
            for (int i = 0; i < table.Columns.Count; i++)
            {
                title += table.Columns[i].ColumnName + "\t"; //栏位：自动跳到下一单元格
            }
            title = title.Substring(0, title.Length - 1) + "\n";
            sw.Write(title);
            foreach (DataRow row in table.Rows)
            {
                string line = "";
                for (int i = 0; i < table.Columns.Count; i++)
                {
                    line += row[i].ToString().Trim() + "\t"; //内容：自动跳到下一单元格
                }
                line = line.Substring(0, line.Length - 1) + "\n";
                sw.Write(line);
            }
            sw.Close();
            fs.Close();
        }

        /// 将json转换为DataTable
        /// </summary>
        /// <param name="strJson">得到的json</param>
        /// <returns></returns>
        public static DataTable ToDataTable(string json)
        {
            DataTable dataTable = new DataTable();  //实例化
            DataTable result;
            JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
            javaScriptSerializer.MaxJsonLength = Int32.MaxValue; //取得最大数值
            ArrayList arrayList = javaScriptSerializer.Deserialize<ArrayList>(json);
            if (arrayList.Count > 0)
            {
                foreach (Dictionary<string, object> dictionary in arrayList)
                {
                    //if (dictionary.Keys.Count<string>() == 0)
                    if (dictionary.Keys.Count == 0)
                    {
                        result = dataTable;
                        return result;
                    }
                    if (dataTable.Columns.Count == 0)
                    {
                        foreach (string current in dictionary.Keys)
                        {

                            if (dictionary[current] == null)
                            {
                                dataTable.Columns.Add(current, typeof(string));
                            }
                            else
                            {
                                dataTable.Columns.Add(current, dictionary[current].GetType());
                            }
                            dataTable.Columns[current].AllowDBNull = true;
                        }
                    }
                    DataRow dataRow = dataTable.NewRow();
                    foreach (string current in dictionary.Keys)
                    {
                        try
                        {
                            dataRow[current] = dictionary[current] == null ? DBNull.Value : dictionary[current];
                        }
                        catch (Exception e)
                        {
                            //dataTable.Columns[current].AllowDBNull=true;
                            dataTable.Columns[current].DataType = dictionary[current].GetType();
                            dataRow[current] = dictionary[current] == null ? DBNull.Value : dictionary[current];
                        }

                    }

                    dataTable.Rows.Add(dataRow);
                }
            }
            result = dataTable;
            return result;
        }

    }
}