From b041c5fde1e114682bcbe2e4c471ae44e22a4086 Mon Sep 17 00:00:00 2001
From: Benjamin Ifland <smuddyx@gmail.com>
Date: Sat, 23 Mar 2019 10:29:18 +0100
Subject: [PATCH] file download

---
 API/API/Controllers/FilesController.cs | 35 ++++++++++++++++++++------
 API/API/Services/FileService.cs        | 16 ++++++++----
 API/Models/File.cs                     |  2 ++
 3 files changed, 40 insertions(+), 13 deletions(-)

diff --git a/API/API/Controllers/FilesController.cs b/API/API/Controllers/FilesController.cs
index 0ac7387..8152d50 100644
--- a/API/API/Controllers/FilesController.cs
+++ b/API/API/Controllers/FilesController.cs
@@ -1,5 +1,8 @@
 using API.Database;
 using API.Services;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
@@ -9,6 +12,7 @@ namespace API.Controllers {
     public class FilesController : ApiController {
         private readonly DataContext dataContext;
         private readonly IFileService fileService;
+        private readonly string dataPath;
 
         public FilesController(
             DataContext dataContext,
@@ -16,29 +20,44 @@ namespace API.Controllers {
             ) {
             this.dataContext = dataContext;
             this.fileService = fileService;
+
+            dataPath = System.Web.Hosting.HostingEnvironment.MapPath(@"~/App_Data");
         }
 
         // GET: api/Files/5
         [Route("api/songs/{songId}/files/{fileId}")]
-        public string Get(int id) {
-            return "value";
+        public HttpResponseMessage Get(long songId, long fileId) {
+            var response = new HttpResponseMessage(HttpStatusCode.OK);
+
+            var file = dataContext.Files.Find(fileId);
+            if (file == null || file.Song.ID != songId) return new HttpResponseMessage(HttpStatusCode.NotFound);
+            var reference = file.ReferenceFile;
+            var filename = file.Name;
+
+            var stream = fileService.Load(dataPath, reference.ToString());
+            response.Content = new StreamContent(stream);
+            response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
+            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") {
+                FileName = filename
+            };
+            return response;
         }
 
         // POST: api/Files
         [Route("api/songs/{songId}/files")]
-        public async Task<IHttpActionResult> Post(long songId, CancellationToken c) {
+        public async Task<HttpResponseMessage> Post(long songId, CancellationToken c) {
             // get file from network input
             var files = HttpContext.Current.Request.Files;
-            if (files.Count != 1) return BadRequest();
+            if (files.Count != 1) return new HttpResponseMessage(HttpStatusCode.BadRequest);
             var file = HttpContext.Current.Request.Files[0];
 
             // find song in database
             var song = dataContext.Songs.Find(songId);
-            if (song == null) return NotFound();
+            if (song == null) return new HttpResponseMessage(HttpStatusCode.NotFound);
 
             // save file in App_Data
-            var path = System.Web.Hosting.HostingEnvironment.MapPath(@"~/App_Data");
-            var filename = await fileService.Save(file, path, c);
+            var stream = file.InputStream;
+            var filename = await fileService.Save(stream, dataPath, c);
 
             // attach file reference to song
             song.Files.Add(new Models.File {
@@ -47,7 +66,7 @@ namespace API.Controllers {
             });
             await dataContext.SaveChangesAsync(c);
 
-            return Ok();
+            return new HttpResponseMessage(HttpStatusCode.OK);
         }
 
 
diff --git a/API/API/Services/FileService.cs b/API/API/Services/FileService.cs
index 24415bd..43c4f11 100644
--- a/API/API/Services/FileService.cs
+++ b/API/API/Services/FileService.cs
@@ -2,25 +2,31 @@
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Web;
 
 namespace API.Services {
     public interface IFileService {
-        Task<Guid> Save(HttpPostedFile file, string path, CancellationToken c);
+        Task<Guid> Save(Stream file, string path, CancellationToken c);
+        Stream Load(string path, string filename);
     }
 
     public class FileService : IFileService {
         private const int bufferSize = 4096;
 
-        public async Task<Guid> Save(HttpPostedFile file, string path, CancellationToken c) {
+        public async Task<Guid> Save(Stream inputStream, string path, CancellationToken c) {
             var filename = Guid.NewGuid();
             var fullPath = Path.Combine(path, filename.ToString());
-            using (var fs = new FileStream(fullPath, FileMode.Create, FileAccess.Write, FileShare.None, bufferSize, true)) {
-                await file.InputStream.CopyToAsync(fs, bufferSize, c);
+            using (var fileStream = new FileStream(fullPath, FileMode.Create, FileAccess.Write, FileShare.None, bufferSize, true)) {
+                await inputStream.CopyToAsync(fileStream, bufferSize, c);
             }
 
             return filename;
         }
+        
+        public Stream Load(string path, string filename) {
+            var fullPath = Path.Combine(path, filename.ToString());
+            var fileStream = new FileStream(fullPath, FileMode.Open, FileAccess.Read, FileShare.None, bufferSize, true);
+            return fileStream;
+        }
 
     }
 }
\ No newline at end of file
diff --git a/API/Models/File.cs b/API/Models/File.cs
index 5b5a496..3febd81 100644
--- a/API/Models/File.cs
+++ b/API/Models/File.cs
@@ -8,5 +8,7 @@ namespace API.Models {
         public Guid ReferenceFile { get; set; }
         public string Name { get; set; }
         public FileType FileType { get; set; }
+
+        public virtual Song Song { get; set; }
     }
 }
\ No newline at end of file