Refactoring HOS folder structure (#771)

* Refactoring HOS folder structure

Refactoring HOS folder structure:

- Added some subfolders when needed (Following structure decided in private).
- Added some `Types` folders when needed.
- Little cleanup here and there.
- Add services placeholders for every HOS services (close #766 and #753).

* Remove Types namespaces

Ryujinx.HLE/HOS/Services/Fs/FileSystemProxy/FileSystemProxyHelper.cs

@@ -0,0 +1,144 @@
+using LibHac;
+using LibHac.Fs;
+using LibHac.Fs.NcaUtils;
+using Ryujinx.Common;
+using Ryujinx.HLE.FileSystem;
+using Ryujinx.HLE.Utilities;
+using System.IO;
+
+namespace Ryujinx.HLE.HOS.Services.Fs.FileSystemProxy
+{
+    static class FileSystemProxyHelper
+    {
+        public static ResultCode LoadSaveDataFileSystem(ServiceCtx context, bool readOnly, out IFileSystem loadedFileSystem)
+        {
+            loadedFileSystem = null;
+
+            SaveSpaceId  saveSpaceId  = (SaveSpaceId)context.RequestData.ReadInt64();
+            ulong        titleId      = context.RequestData.ReadUInt64();
+            UInt128      userId       = context.RequestData.ReadStruct<UInt128>();
+            long         saveId       = context.RequestData.ReadInt64();
+            SaveDataType saveDataType = (SaveDataType)context.RequestData.ReadByte();
+            SaveInfo     saveInfo     = new SaveInfo(titleId, saveId, saveDataType, saveSpaceId, userId);
+            string       savePath     = context.Device.FileSystem.GetSavePath(context, saveInfo);
+
+            try
+            {
+                LocalFileSystem       fileSystem     = new LocalFileSystem(savePath);
+                LibHac.Fs.IFileSystem saveFileSystem = new DirectorySaveDataFileSystem(fileSystem);
+
+                if (readOnly)
+                {
+                    saveFileSystem = new ReadOnlyFileSystem(saveFileSystem);
+                }
+
+                loadedFileSystem = new IFileSystem(saveFileSystem);
+            }
+            catch (HorizonResultException ex)
+            {
+                return (ResultCode)ex.ResultValue.Value;
+            }
+
+            return ResultCode.Success;
+        }
+
+        public static ResultCode OpenNsp(ServiceCtx context, string pfsPath, out IFileSystem openedFileSystem)
+        {
+            openedFileSystem = null;
+
+            try
+            {
+                LocalStorage        storage = new LocalStorage(pfsPath, FileAccess.Read, FileMode.Open);
+                PartitionFileSystem nsp     = new PartitionFileSystem(storage);
+
+                ImportTitleKeysFromNsp(nsp, context.Device.System.KeySet);
+
+                openedFileSystem = new IFileSystem(nsp);
+            }
+            catch (HorizonResultException ex)
+            {
+                return (ResultCode)ex.ResultValue.Value;
+            }
+
+            return ResultCode.Success;
+        }
+
+        public static ResultCode OpenNcaFs(ServiceCtx context, string ncaPath, LibHac.Fs.IStorage ncaStorage, out IFileSystem openedFileSystem)
+        {
+            openedFileSystem = null;
+
+            try
+            {
+                Nca nca = new Nca(context.Device.System.KeySet, ncaStorage);
+
+                if (!nca.SectionExists(NcaSectionType.Data))
+                {
+                    return ResultCode.PartitionNotFound;
+                }
+
+                LibHac.Fs.IFileSystem fileSystem = nca.OpenFileSystem(NcaSectionType.Data, context.Device.System.FsIntegrityCheckLevel);
+
+                openedFileSystem = new IFileSystem(fileSystem);
+            }
+            catch (HorizonResultException ex)
+            {
+                return (ResultCode)ex.ResultValue.Value;
+            }
+
+            return ResultCode.Success;
+        }
+
+        public static ResultCode OpenFileSystemFromInternalFile(ServiceCtx context, string fullPath, out IFileSystem openedFileSystem)
+        {
+            openedFileSystem = null;
+
+            DirectoryInfo archivePath = new DirectoryInfo(fullPath).Parent;
+
+            while (string.IsNullOrWhiteSpace(archivePath.Extension))
+            {
+                archivePath = archivePath.Parent;
+            }
+
+            if (archivePath.Extension == ".nsp" && File.Exists(archivePath.FullName))
+            {
+                FileStream pfsFile = new FileStream(
+                    archivePath.FullName.TrimEnd(Path.DirectorySeparatorChar),
+                    FileMode.Open,
+                    FileAccess.Read);
+
+                try
+                {
+                    PartitionFileSystem nsp = new PartitionFileSystem(pfsFile.AsStorage());
+
+                    ImportTitleKeysFromNsp(nsp, context.Device.System.KeySet);
+                    
+                    string filename = fullPath.Replace(archivePath.FullName, string.Empty).TrimStart('\\');
+
+                    if (nsp.FileExists(filename))
+                    {
+                        return OpenNcaFs(context, fullPath, nsp.OpenFile(filename, OpenMode.Read).AsStorage(), out openedFileSystem);
+                    }
+                }
+                catch (HorizonResultException ex)
+                {
+                    return (ResultCode)ex.ResultValue.Value;
+                }
+            }
+
+            return ResultCode.PathDoesNotExist;
+        }
+
+        public static void ImportTitleKeysFromNsp(LibHac.Fs.IFileSystem nsp, Keyset keySet)
+        {
+            foreach (DirectoryEntry ticketEntry in nsp.EnumerateEntries("*.tik"))
+            {
+                Ticket ticket = new Ticket(nsp.OpenFile(ticketEntry.FullPath, OpenMode.Read).AsStream());
+
+                if (!keySet.TitleKeys.ContainsKey(ticket.RightsId))
+                {
+                    keySet.TitleKeys.Add(ticket.RightsId, ticket.GetTitleKey(keySet));
+                }
+            }
+        }
+    }
+}