using Renci.SshNet;
using SendGrid;
using SendGrid.Helpers.Mail;
using System;
using System.IO;
using System.Linq;

namespace PlayBall
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            var _sendGridApiKey = "";

            Console.WriteLine("Connecting...");

            using (var sftpClient = new SftpClient("server", "user", new PrivateKeyFile("rsa.key")))
            {
                sftpClient.Connect();

                var files = sftpClient.ListDirectory("/directory");
                var mostRecentFile = files.OrderByDescending(f => f.Name).FirstOrDefault();

                if (mostRecentFile == null)
                {
                    Console.WriteLine("Failed to get most recent file.");
                    return;
                }

                Console.WriteLine($"{mostRecentFile.Name}");

                using (var ms = new MemoryStream())
                {
                    sftpClient.DownloadFile(mostRecentFile.FullName, ms);
                    var fileContents = Convert.ToBase64String(ms.ToArray());

                    var mailClient = new SendGridClient(_sendGridApiKey);

                    var msg = new SendGridMessage()
                    {
                        From = new EmailAddress("user@example.com", "Example User"),
                        Subject = "Recent File",
                        PlainTextContent = "Attached is the most recent file by name.",
                    };
                    msg.AddTo(new EmailAddress("anotheruser@example.com"));

                    msg.AddAttachment(mostRecentFile.Name, fileContents);

                    var response = mailClient.SendEmailAsync(msg).Result;
                    Console.WriteLine(response.StatusCode);
                }
            }
        }
    }
}