using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

//using Renci.SshNet;
//using Renci.SshNet.Common;
//using Renci.SshNet.Sftp;
using HRM.BO;
using HRM.DA;
using System.IO;
using System.Configuration;
using Microsoft.Extensions.Configuration;
using Renci.SshNet;
using System.Data;
using System.Data.OleDb;


namespace HRM.MailNotificationProcess
{
    
    public class SFTPInterface
    {
        HRM.BO.Configuration.SFTPSettings sftpsetting = new BO.Configuration.SFTPSettings();
        public List<string> DownloadFile()
        {   // For selected File
            //try
            //{
            //    var builder = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json");
            //    IConfiguration Configuration = builder.Build();
            //    Configuration.GetSection("SFTPSettings").Bind(sftpsetting);
            //    if (sftpsetting.HostName != String.Empty)
            //    {
            //        using (var sftp = new SftpClient(sftpsetting.HostName, sftpsetting.Port,
            //            sftpsetting.UserName, sftpsetting.Password))
            //        {
            //            sftp.Connect();

            //            using (var file = File.OpenWrite(sftpsetting.LocalDestinationFilename))
            //            {
            //                sftp.DownloadFile(sftpsetting.RemoteFileName, file);
            //            }

            //            sftp.Disconnect();
            //            // write in text file
            //            // Date and Time, successfull
            //        }
            //    }

            //}
            List<string> downloadedFiles = new List<string>();
            //DataTable allData = null;
            try
            {
                var builder = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json");
                IConfiguration Configuration = builder.Build();
                Configuration.GetSection("SFTPSettings").Bind(sftpsetting);

                if (!string.IsNullOrEmpty(sftpsetting.HostName))
                {
                    using (var sftp = new SftpClient(sftpsetting.HostName, sftpsetting.Port,
                        sftpsetting.UserName, sftpsetting.Password))
                    {
                        sftp.Connect();
                        DownloadSftpDirectory(sftp, sftpsetting.RemoteFileName, sftpsetting.LocalDestinationFilename);
                        string localDirectoryPath = sftpsetting.LocalDestinationFilename;  
                        var filesInDirectory = Directory.GetFiles(localDirectoryPath, "*.xlsx");

                        downloadedFiles.AddRange(filesInDirectory);


                        sftp.Disconnect();

                        // write in text file
                        // Date and Time, successfull
                    }
                }
            }

            catch (Exception ex)
            {
                // write in text file
                // Date and Time, unsuccessfull, Error message ( 2000 character) 
            }
            return downloadedFiles;
        }

        private void DownloadSftpDirectory(SftpClient sftp, string remoteDirectory, string localPath)
        {
            if (!sftp.IsConnected)
                throw new Exception("SFTP client not connected.");

            if (!Directory.Exists(localPath))
                Directory.CreateDirectory(localPath);

            var filesAndDirs = sftp.ListDirectory(remoteDirectory);

            foreach (var entry in filesAndDirs)
            {
                if (entry.IsDirectory && entry.Name != "." && entry.Name != "..")
                {
                    DownloadSftpDirectory(sftp, entry.FullName, Path.Combine(localPath, entry.Name));
                }
                else if (entry.IsRegularFile)
                {
                    string localFilePath = Path.Combine(localPath, entry.Name);
                    using (var file = File.OpenWrite(localFilePath))
                    {
                        sftp.DownloadFile(entry.FullName, file);
                    }
                }
            }
        }



        public DataTable ReadExcelToDataTable(string path)
            {
                string connString = "";
                string extension = System.IO.Path.GetExtension(path);

                if (extension == ".xlsx")
                {
                    connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1\";";
                }
                else if (extension == ".xls")
                {
                    connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\";";
                }

                using (OleDbConnection conn = new OleDbConnection(connString))
                {
                    conn.Open();
                    DataTable dtSchema = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                    string sheetName = dtSchema.Rows[0]["TABLE_NAME"].ToString(); 

                    OleDbCommand cmd = new OleDbCommand("SELECT * FROM [" + sheetName + "]", conn);
                    OleDbDataAdapter da = new OleDbDataAdapter(cmd);

                    DataTable dt = new DataTable();
                    da.Fill(dt);
                    return dt;
                }
            }

        public DataTable LoadAllExcelFilesToDataTable(string directoryPath)
        {
            DataTable aggregatedDataTable = new DataTable();

            string[] excelFiles = Directory.GetFiles(directoryPath, "*.xlsx");

            foreach (string filePath in excelFiles)
            {
                DataTable currentDataTable = ReadExcelToDataTable(filePath);
                aggregatedDataTable.Merge(currentDataTable);
            }

            return aggregatedDataTable;
        }

    }



}