/ThinkEmailFomatter/Controllers/AttachmentsController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Configuration;
using System.IO;
using ThinkEmailFormatter.Models.Extensions;
using ThinkEmailFormatter.Models;

namespace ThinkEmailFormatter.Controllers
{
    public class AttachmentsController : BaseController
    {
        public AttachmentsController(IControllerAggregateService controllerAggregateService)
            : base(controllerAggregateService)
        { 
        }

        public ActionResult Index()
        {
            string attachmentsRepo = ConfigurationManager.AppSettings["Attachments.Repo"];
            // Get all "cshtml" files from that folder
            string[] filePaths = Directory.GetFiles(attachmentsRepo, "*");
            // For each files, get rid of the extension file
            var attachments = filePaths.Select(f => f.Split('\\').Last());

            return View(attachments);
        }

        /// <summary>
        /// Check if template exists in the file system.
        /// That is the first part of a 2 steps process to Upload 
        /// a new file to the file system. This first part is asynchronously 
        /// requested from the client using jQuery. Then, depending on the 
        /// client response to that first step, the second step(UploadTemplate)
        /// may or may not be requested
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        [HttpPost]
        public JsonResult CheckAttachmentExists(string fileName)
        {
            try
            {
                string filePath = string.Format(@"{0}{1}", ConfigurationManager.AppSettings["Attachments.Repo"], fileName);
                bool fileExists = System.IO.File.Exists(filePath);

                if (fileExists)
                {
                    return Json(new { code = "existingfile", message = "This file already exists." });
                }
                else
                {
                    return Json(new { code = "newfile", message = "This file does not exist yet." });
                }
            }
            catch (Exception ie)
            {
                _aggSvc.Log.Exception(ie);
                return Json(new { code = "error", message = "An error occured. Please try again." });
            }
        }

        /// <summary>
        /// Upload template file to the file system.
        /// That is the second part of a 2 steps process to Upload 
        /// a new file to the file system. The first step was the client asynchronous 
        /// request(using jQuery) to the "CheckTemplateExists" method
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        [HttpPost]
        public ActionResult UploadAttachment(HttpPostedFileBase file)
        {
            try
            {
                // Verify that the user selected a file
                if (file != null && file.ContentLength > 0)
                {
                    string fileNameWithExt = Path.GetFileName(file.FileName);
                    string filePath = string.Format(@"{0}{1}", ConfigurationManager.AppSettings["Attachments.Repo"], fileNameWithExt);
                    bool fileExists = System.IO.File.Exists(filePath);

                    if (fileExists)
                        System.IO.File.Delete(filePath);

                    file.SaveAs(filePath);
                }
                // redirect back to the index action to show the form once again
                return RedirectToAction("Index");
            }
            catch (Exception ie)
            {
                _aggSvc.Log.Exception(ie);
                return View("Error");
            }
        }

        public ActionResult DeleteAttachment(string fileName)
        {
            try
            {
                string filePath = string.Format(@"{0}{1}", ConfigurationManager.AppSettings["Attachments.Repo"], fileName);
                bool fileExists = System.IO.File.Exists(filePath);

                if (fileExists)
                {
                    System.IO.File.Delete(filePath);
                }

                return RedirectToAction("Index");
            }
            catch (Exception ie)
            {
                _aggSvc.Log.Exception(ie);
                return View("Error");
            }
        }
    }
}