using System;
using System.IO;
using System.Net.Sockets;
using System.Collections.Generic;
using System.Threading.Tasks;
using Renci.SshNet;
using Renci.SshNet.Common;

namespace SSH_Sandbox
{
    public struct SftpReport
    {
        public string hostname;
        public int port;
        public string directory;
        public string username;
        public string password;
        public string fileLocation;

        public SftpReport(string host, int port, string dir,string uName, string passwd, string fileLoc)
        {
            this.hostname = host;
            this.port = port;
            this.directory = dir;
            this.username = uName;
            this.password = passwd;
            this.fileLocation = fileLoc;
        }
    }


    class Program
    {
        static void Main(string[] args)
        {
            List<SftpReport> reports = GenerateTestReports();

            foreach (var report in reports)
            {
                Task.Run(()=> UploadFileToSftpClient(report));
            }

            Console.WriteLine("Application end.");
            Console.Read();
        }

        static List<SftpReport> GenerateTestReports()
        {
            List<SftpReport> reports = new List<SftpReport>();

            reports.Add(new SftpReport("localhost", 22, "/upload/jamie", "foo", "pass", @"c:/Test/sftp.txt"));

            return reports;
        }

        static async Task UploadFileToSftpClient(SftpReport report)
        {
            var connInfo = new ConnectionInfo(report.hostname, report.port, report.username, new PasswordAuthenticationMethod(report.username, report.password));
            using (var client = new SftpClient(connInfo))
            {
                try
                {
                    client.Connect();
                    SendFile(client, report.directory, report.fileLocation);
                }
                catch (SocketException sEx)
                {
                    Console.WriteLine($"{client.ConnectionInfo.ServerVersion ?? "Unknown server"} - Error connecting to remote host.    Message : {sEx.Message}");
                }
                catch (SshAuthenticationException sshEx)
                {
                    Console.WriteLine($"{client.ConnectionInfo.ServerVersion ?? "Unknown server"} - Invalid credentials, cannot authenticate.    Message : {sshEx.Message}");
                }
                catch (SftpPermissionDeniedException pdEx)
                {
                    Console.WriteLine($"{client.ConnectionInfo.ServerVersion ?? "Unknown server"} - Permission denied.    Message : {pdEx.Message}");
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"An unexpected error has occured: {ex.GetType()} - {ex.Message}");
                }
            }
        }

        static void SendFile(SftpClient client, string directory, string file)
        {
            if (!DirectoryExists(client, directory))
            {
                client.CreateDirectory(directory);
            }
            client.ChangeDirectory(directory);

            TransferFileToServer(client, file);
        }

        static bool DirectoryExists(SftpClient client, string directory)
        {
            try
            {
                client.ListDirectory(directory);
                return true;
            }
            catch (SftpPathNotFoundException ex)
            {
                return false;
            }
        }

        static void TransferFileToServer(SftpClient client, string filePath)
        {
            Random rand = new Random();

            using (var fileStream = new FileStream(filePath, FileMode.Open))
            {
                client.BufferSize = 4 * 1024;
                client.UploadFile(fileStream, $"Report {rand.Next()}.xml");
            }
        }
    }
}