Partsource/PartSource.Automation/Services/FtpService.cs

using Microsoft.Extensions.Configuration;
using PartSource.Automation.Models.Configuration;
using PartSource.Automation.Models.Ftp;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Net;
using System.Threading.Tasks;

namespace PartSource.Automation.Services
{
    public class FtpService
    {
        private readonly FtpConfiguration _ftpConfiguration;

        public FtpService(FtpConfiguration ftpConfiguration)
        {
            _ftpConfiguration = ftpConfiguration;
        }

        public IList<FtpFileInfo> ListFilesExtended(string directory = "")
        {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(new Uri($"{_ftpConfiguration.Url}/{directory}"));
            request.Credentials = new NetworkCredential(_ftpConfiguration.Username, _ftpConfiguration.Password);
            request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;

            using FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            using StreamReader reader = new StreamReader(response.GetResponseStream());

            IList<FtpFileInfo> files = new List<FtpFileInfo>();
            string[] fileStrings = reader.ReadToEnd().Split("\r\n");

            foreach (string fileString in fileStrings)
            {
                if (string.IsNullOrEmpty(fileString))
                {
                    continue;
                }

                string dateString = fileString[..17];
                string[] sizeAndName = fileString[18..].TrimStart().Split(" ", 2);

                if (sizeAndName[0].ToUpperInvariant().IndexOf("DIR") > -1)
                {
                    files.Add(new FtpFileInfo
                    {
                        Modified = DateTime.Parse(fileString[..17]),
                        Size = 0,
                        Filename = sizeAndName[1].Trim(),
                        FileType = FtpFileType.Directory
                    });
                }

                else
                {
                    files.Add(new FtpFileInfo
                    {
                        Modified = DateTime.Parse(fileString[..17]),
                        Size = long.Parse(sizeAndName[0]),
                        Filename = sizeAndName[1].Trim(),
                        FileType = FtpFileType.File
                    });
                }
            }

            return files;
        }

        public string[] ListFiles(string directory = "")
        {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(new Uri($"{_ftpConfiguration.Url}/{directory}"));
            request.Credentials = new NetworkCredential(_ftpConfiguration.Username, _ftpConfiguration.Password);
            request.Method = WebRequestMethods.Ftp.ListDirectory;

            using FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            using StreamReader reader = new StreamReader(response.GetResponseStream());

            string files = reader.ReadToEnd();

            return files.Length > 0
                ? files.Split("\r\n")
                : Array.Empty<string>();
        }

        public string Download(string filename, string destination = null)
        {
            

            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(new Uri($"{_ftpConfiguration.Url}/{filename}"));
            request.Credentials = new NetworkCredential(_ftpConfiguration.Username, _ftpConfiguration.Password);
            request.Method = WebRequestMethods.Ftp.DownloadFile;

            if (string.IsNullOrEmpty(destination))
            {
                destination = _ftpConfiguration.Destination;
            }

            if (Path.DirectorySeparatorChar == '\\')
            {
                filename = filename.Replace("/", "\\");
            }

            destination = Path.Combine(destination, filename);
            string destinationDirectory = Path.GetDirectoryName(destination);
            if (!Directory.Exists(destinationDirectory))
            {
                Directory.CreateDirectory(destinationDirectory);
            }
            
            using FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            using Stream responseStream = response.GetResponseStream();
            using FileStream fileStream = new FileStream(destination, FileMode.Create);

            responseStream.CopyTo(fileStream);

            return destination;
        }
    }
}