using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Txgy.EWS.Client.PageModule.Services
{
    public class DownloadJsonFile
    {
        public int Download(string eventTime, string savePath, string saveName, string tableName)
        {
            string connStr = ConfigurationManager.ConnectionStrings["TencetnMySQL"].ConnectionString;
            MySqlConnection RemoteConn = new MySqlConnection(connStr);
            string courseSql = @"select JsonFile from " + tableName + " where EventTime=@eventTime";
            MySqlCommand Comm = new MySqlCommand(courseSql, RemoteConn);
            MySqlDataReader DataReader = null;
            try
            {
                if (RemoteConn.State != ConnectionState.Open)
                {
                    RemoteConn.Open();
                }

                Comm.Parameters.AddWithValue("@eventTime", eventTime);
                DataReader = Comm.ExecuteReader();
                List<byte> wds = new List<byte>();
                //开始读数据
                while (DataReader.Read())
                {
                    byte[] blob;
                    blob = (byte[])DataReader["JsonFile"];
                    if (blob.Length == 0)
                        break;
                    wds.AddRange(blob);
                }
                string jsonPath = savePath + saveName;
                if (!Directory.Exists(savePath))
                {
                    Directory.CreateDirectory(savePath);
                }
                int len = -1;
                using (FileStream fs = new FileStream(jsonPath, FileMode.OpenOrCreate))
                {
                    using (BinaryWriter binWriter = new BinaryWriter(fs))
                    {
                        binWriter.Write(wds.ToArray());
                        len = (int)new FileInfo(jsonPath).Length;
                    }
                }
                if (len == wds.Count)
                {
                    return wds.Count;
                }
                return -1;

            }
            catch(Exception ex) 
            {
                throw ex;
            }
            finally
            {
                if (DataReader != null)
                {
                    DataReader.Dispose();
                    DataReader = null;
                }
                if (Comm != null)
                {
                    Comm.Dispose();
                    Comm = null;
                }
                if (RemoteConn != null)
                {
                    RemoteConn.Close();
                    RemoteConn.Dispose();
                    RemoteConn = null;
                }
            }
        }
    }
}