FileSystem: Creating an api to retrieve a file mime type

Kyoo.Common/Controllers/IFileSystem.cs

@@ -2,11 +2,25 @@ using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
-using Kyoo.Models;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Kyoo.Controllers
 {
+	/// <summary>
+	/// A class wrapping a value that will be set after the completion of the task it is related to.
+	/// </summary>
+	/// <remarks>
+	/// This class replace the use of an out parameter on a task since tasks and out can't be combined.
+	/// </remarks>
+	/// <typeparam name="T">The type of the value</typeparam>
+	public class AsyncRef<T>
+	{
+		/// <summary>
+		/// The value that will be set before the completion of the task.
+		/// </summary>
+		public T Value { get; set; }
+	}
+	
 	/// <summary>
 	/// A service to abstract the file system to allow custom file systems (like distant file systems or external providers)
 	/// </summary>
@@ -42,6 +56,16 @@ namespace Kyoo.Controllers
 		/// <exception cref="FileNotFoundException">If the file could not be found.</exception>
 		/// <returns>A reader to read the file.</returns>
 		public Task<Stream> GetReader([NotNull] string path);
+		
+		/// <summary>
+		/// Read a file present at <paramref name="path"/>. The reader can be used in an arbitrary context.
+		/// To return files from an http endpoint, use <see cref="FileResult"/>.
+		/// </summary>
+		/// <param name="path">The path of the file</param>
+		/// <param name="mime">The mime type of the opened file.</param>
+		/// <exception cref="FileNotFoundException">If the file could not be found.</exception>
+		/// <returns>A reader to read the file.</returns>
+		public Task<Stream> GetReader([NotNull] string path, AsyncRef<string> mime);
 
 		/// <summary>
 		/// Create a new file at <paramref name="path"></paramref>.

Kyoo.Common/Controllers/IThumbnailsManager.cs

@@ -1,5 +1,4 @@
-using System;
+using Kyoo.Models;
-using Kyoo.Models;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
 
@@ -27,13 +26,12 @@ namespace Kyoo.Controllers
 
 
 		/// <summary>
-		/// Retrieve the local path of the poster of the given item.
+		/// Retrieve the local path of an image of the given item.
 		/// </summary>
 		/// <param name="item">The item to retrieve the poster from.</param>
 		/// <param name="imageID">The ID of the image. See <see cref="Images"/> for values.</param>
 		/// <typeparam name="T">The type of the item</typeparam>
-		/// <exception cref="NotSupportedException">If the type does not have a poster</exception>
+		/// <returns>The path of the image for the given resource or null if it does not exists.</returns>
-		/// <returns>The path of the poster for the given resource (it might or might not exists).</returns>
 		Task<string> GetImagePath<T>([NotNull] T item, int imageID)
 			where T : IThumbnails;
 	}

Kyoo/Controllers/FileSystems/FileSystemComposite.cs

@@ -107,6 +107,15 @@ namespace Kyoo.Controllers
 				.GetReader(relativePath);
 		}
 
+		/// <inheritdoc />
+		public Task<Stream> GetReader(string path, AsyncRef<string> mime)
+		{
+			if (path == null)
+				throw new ArgumentNullException(nameof(path));
+			return _GetFileSystemForPath(path, out string relativePath)
+				.GetReader(relativePath, mime);
+		}
+
 		/// <inheritdoc />
 		public Task<Stream> NewFile(string path)
 		{
@@ -181,10 +190,11 @@ namespace Kyoo.Controllers
 					Season season => await GetExtraDirectory(season.Show),
 					Episode episode => await GetExtraDirectory(episode.Show),
 					Track track => await GetExtraDirectory(track.Episode),
-					IResource res => Combine(_options.CurrentValue.MetadataPath, typeof(T).Name, res.Slug),
+					IResource res => Combine(_options.CurrentValue.MetadataPath, 
-					_ => Combine(_options.CurrentValue.MetadataPath, typeof(T).Name)
+						typeof(T).Name.ToLowerInvariant(), res.Slug),
+					_ => Combine(_options.CurrentValue.MetadataPath, typeof(T).Name.ToLowerInvariant())
 				};
-			return path;
+			return await CreateDirectory(path);
 		}
 	}
 }

Kyoo/Controllers/FileSystems/HttpFileSystem.cs

@@ -4,7 +4,6 @@ using System.IO;
 using System.Net.Http;
 using System.Threading.Tasks;
 using Kyoo.Common.Models.Attributes;
-using Kyoo.Models;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Kyoo.Controllers
@@ -44,6 +43,16 @@ namespace Kyoo.Controllers
 			HttpClient client = _clientFactory.CreateClient();
 			return client.GetStreamAsync(path);
 		}
+		
+		/// <inheritdoc />
+		public async Task<Stream> GetReader(string path, AsyncRef<string> mime)
+		{
+			HttpClient client = _clientFactory.CreateClient();
+			HttpResponseMessage response = await client.GetAsync(path);
+			response.EnsureSuccessStatusCode();
+			mime.Value = response.Content.Headers.ContentType?.MediaType;
+			return await response.Content.ReadAsStreamAsync();
+		}
 
 		/// <inheritdoc />
 		public Task<Stream> NewFile(string path)

Kyoo/Controllers/FileSystems/LocalFileSystem.cs

@@ -78,6 +78,16 @@ namespace Kyoo.Controllers
 				throw new ArgumentNullException(nameof(path));
 			return Task.FromResult<Stream>(File.OpenRead(path));
 		}
+		
+		/// <inheritdoc />
+		public Task<Stream> GetReader(string path, AsyncRef<string> mime)
+		{
+			if (path == null)
+				throw new ArgumentNullException(nameof(path));
+			_provider.TryGetContentType(path, out string mimeValue);
+			mime.Value = mimeValue;
+			return Task.FromResult<Stream>(File.OpenRead(path));
+		}
 
 		/// <inheritdoc />
 		public Task<Stream> NewFile(string path)

Kyoo/Controllers/ThumbnailsManager.cs

@@ -47,7 +47,9 @@ namespace Kyoo.Controllers
 
 			try
 			{
-				await using Stream reader = await _files.GetReader(url);
+				AsyncRef<string> mime = new();
+				await using Stream reader = await _files.GetReader(url, mime);
+				// TODO use this mime type to guess the file extension.
 				await using Stream local = await _files.NewFile(localPath);
 				await reader.CopyToAsync(local);
 				return true;
@@ -58,7 +60,7 @@ namespace Kyoo.Controllers
 				return false;
 			}
 		}
-		
+
 		/// <inheritdoc />
 		public async Task<bool> DownloadImages<T>(T item, bool alwaysDownload = false) 
 			where T : IThumbnails
@@ -74,28 +76,32 @@ namespace Kyoo.Controllers
 
 			foreach ((int id, string image) in item.Images.Where(x => x.Value != null))
 			{
-				string localPath = await GetImagePath(item, id);
+				string localPath = await _GetPrivateImagePath(item, id);
 				if (alwaysDownload || !await _files.Exists(localPath))
 					ret |= await _DownloadImage(image, localPath, $"The image n°{id} of {name}");
 			}
 			
 			return ret;
 		}
-		
+
-		/// <inheritdoc />
+		/// <summary>
-		public async Task<string> GetImagePath<T>(T item, int imageID)
+		/// Retrieve the local path of an image of the given item <b>without an extension</b>.
-			where T : IThumbnails
+		/// </summary>
+		/// <param name="item">The item to retrieve the poster from.</param>
+		/// <param name="imageID">The ID of the image. See <see cref="Images"/> for values.</param>
+		/// <typeparam name="T">The type of the item</typeparam>
+		/// <returns>The path of the image for the given resource, <b>even if it does not exists</b></returns>
+		private async Task<string> _GetPrivateImagePath<T>(T item, int imageID)
 		{
 			if (item == null)
 				throw new ArgumentNullException(nameof(item));
-			// TODO handle extensions
 			string imageName = imageID switch
 			{
-				Images.Poster => "poster.jpg",
+				Images.Poster => "poster",
-				Images.Logo => "logo.jpg",
+				Images.Logo => "logo",
-				Images.Thumbnail => "thumbnail.jpg",
+				Images.Thumbnail => "thumbnail",
-				Images.Trailer => "trailer.mp4",
+				Images.Trailer => "trailer",
-				_ => $"{imageID}.jpg"
+				_ => $"{imageID}"
 			};
 
 			imageName = item switch
@@ -108,5 +114,16 @@ namespace Kyoo.Controllers
 
 			return _files.Combine(await _files.GetExtraDirectory(item), imageName);
 		}
+		
+		/// <inheritdoc />
+		public async Task<string> GetImagePath<T>(T item, int imageID)
+			where T : IThumbnails
+		{
+			string basePath = await _GetPrivateImagePath(item, imageID);
+			string directory = Path.GetDirectoryName(basePath);
+			string baseFile = Path.GetFileName(basePath);
+			return (await _files.ListFiles(directory!))
+				.FirstOrDefault(x => Path.GetFileNameWithoutExtension(x) == baseFile);
+		}
 	}
 }