using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SystemX.Product.CP.TRA.Extract
{

    public class DBService
    {
        private string connectionString = "Server=192.168.0.69;Database=CPXV2ShortTermLogJson;User Id=Alis;Password=Kefico!@34;";

        public void GetLargeData()
        {
            // 1. 연결 생성
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                try
                {
                    // 2. 실행할 쿼리 작성 (JOIN 포함)
                    string sql = @"SELECT [TestListFileNo]
                                  ,[StepID]
                                  ,[StepVersion]
                                  ,[StepDesc]
                                  ,[SpecMin]
                                  ,[SpecMax]
                                  ,[Dim]
                              FROM [CPXV2].[dbo].[VRFY_TestListFileRelease] where StepDesc like 'an10_off' order by testlistfileno";

                    SqlCommand cmd = new SqlCommand(sql, conn);
                    // 타임아웃 설정 (600만 건은 시간이 걸릴 수 있으므로 0(무제한) 또는 넉넉하게 설정)
                    cmd.CommandTimeout = 300;
                    conn.Open();

                    // 3. DataReader로 데이터 읽기
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            // 예: 데이터 처리 로직
                            var val = Decompression(reader["LogData"].ToString());
                        }
                    }

                    //sql = @"SELECT * FROM HIST_LogSummary_2025 as Summary with(nolock) JOIN HIST_TestResult_2025 as Result with(nolock) ON Summary.No = Result.No";
                }
                catch (SqlException ex)
                {
                    Console.WriteLine("DB 오류 발생: " + ex.Message);
                }
            }
        }

        public static string Decompression(string compressedDataStr)
        {
            string result = null;
            byte[] buffer = Convert.FromBase64String(compressedDataStr);
            using (MemoryStream stream = new MemoryStream(buffer))
            {
                using (GZipStream stream2 = new GZipStream(stream, CompressionMode.Decompress))
                {
                    using (StreamReader streamReader = new StreamReader(stream2))
                    {
                        result = streamReader.ReadToEnd();
                    }
                }                    
            }

            return result;
        }
    }
}