Added File-Migrate feature

TLSharp.Core/Network/MtProtoSender.cs

@@ -281,6 +281,18 @@ namespace TLSharp.Core.Network
                     var dcIdx = int.Parse(resultString);
                     throw new MigrationNeededException(dcIdx);
                 }
+                else if (errorMessage.StartsWith("FILE_MIGRATE_"))
+                {
+                    var resultString = Regex.Match(errorMessage, @"\d+").Value;
+                    var dcIdx = int.Parse(resultString);
+                    throw new FileMigrationException(dcIdx);
+                }
+                else if (errorMessage.StartsWith("USER_MIGRATE_"))
+                {
+                    var resultString = Regex.Match(errorMessage, @"\d+").Value;
+                    var dcIdx = int.Parse(resultString);
+                    throw new UserMigrationException(dcIdx);
+                }
                 else
                 {
                     throw new InvalidOperationException(errorMessage);
@@ -493,4 +505,26 @@ namespace TLSharp.Core.Network
             DC = dc;
         }
     }
+
+    internal class FileMigrationException : Exception
+    {
+        internal int DC { get; private set; }
+
+        internal FileMigrationException(int dc)
+            : base ($"File is located on a different DC: {dc}. Please migrate.")
+        {
+            DC = dc;
+        }
+    }
+
+    internal class UserMigrationException : Exception
+    {
+        internal int DC { get; private set; }
+
+        internal UserMigrationException(int dc)
+            : base($"User is located on a different DC: {dc}. Please migrate.")
+        {
+            DC = dc;
+        }
+    }
 }

TLSharp.Core/TelegramClient.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using System.Web;
 using TeleSharp.TL;
+using TeleSharp.TL.Account;
 using TeleSharp.TL.Auth;
 using TeleSharp.TL.Contacts;
 using TeleSharp.TL.Help;
@@ -14,6 +15,7 @@ using TLSharp.Core.MTProto.Crypto;
 using TLSharp.Core.Network;
 using TLSharp.Core.Requests;
 using TLSharp.Core.Utils;
+using TLAuthorization = TeleSharp.TL.Auth.TLAuthorization;
 
 namespace TLSharp.Core
 {
@@ -152,12 +154,12 @@ namespace TLSharp.Core
 
             return ((TLUser)request.Response.user);
         }
-        public async Task<T> SendRequestAsync<T>(TLMethod methodtoExceute)
+        public async Task<T> SendRequestAsync<T>(TLMethod methodToExecute)
         {
-            await _sender.Send(methodtoExceute);
+            await _sender.Send(methodToExecute);
-            await _sender.Receive(methodtoExceute);
+            await _sender.Receive(methodToExecute);
             
-            var result = methodtoExceute.GetType().GetProperty("Response").GetValue(methodtoExceute);
+            var result = methodToExecute.GetType().GetProperty("Response").GetValue(methodToExecute);
 
             return (T)result;
         }
@@ -218,7 +220,7 @@ namespace TLSharp.Core
         public async Task<TLAbsUpdates> SendUploadedDocument(
             TLAbsInputPeer peer, TLAbsInputFile file, string caption, string mimeType, TLVector<TLAbsDocumentAttribute> attributes)
         {
-           return await SendRequestAsync<TLAbsUpdates>(new TLRequestSendMedia()
+            return await SendRequestAsync<TLAbsUpdates>(new TLRequestSendMedia()
             {
                 random_id = Helpers.GenerateRandomLong(),
                 background = false,
@@ -236,11 +238,42 @@ namespace TLSharp.Core
 
         public async Task<TLFile> GetFile(TLAbsInputFileLocation location, int filePartSize)
         {
-            return await SendRequestAsync<TLFile>(new TLRequestGetFile()
+            TLFile result = null;
+            try
             {
-                location = location,
+                result = await SendRequestAsync<TLFile>(new TLRequestGetFile()
-                limit = filePartSize
+                {
-            });
+                    location = location,
+                    limit = filePartSize
+                });
+            }
+            catch (FileMigrationException ex)
+            {
+                var exportedAuth = await SendRequestAsync<TLExportedAuthorization>(new TLRequestExportAuthorization() { dc_id = ex.DC });
+
+                var authKey = _session.AuthKey;
+                var timeOffset = _session.TimeOffset;
+                var serverAddress = _session.ServerAddress;
+                var serverPort = _session.Port;
+
+                await ReconnectToDcAsync(ex.DC);
+                var auth = await SendRequestAsync<TLAuthorization>(new TLRequestImportAuthorization
+                {
+                    bytes = exportedAuth.bytes,
+                    id = exportedAuth.id
+                });
+                result = await GetFile(location, filePartSize);
+
+                _session.AuthKey = authKey;
+                _session.TimeOffset = timeOffset;
+                _transport = new TcpTransport(serverAddress, serverPort);
+                _session.ServerAddress =serverAddress;
+                _session.Port = serverPort;
+                await ConnectAsync();
+
+            }
+
+            return result;
         }
 
         private void OnUserAuthenticated(TLUser TLUser)
@@ -256,7 +289,7 @@ namespace TLSharp.Core
     {
         public const string InfoUrl = "https://github.com/sochix/TLSharp#quick-configuration";
 
-        internal MissingApiConfigurationException(string invalidParamName):
+        internal MissingApiConfigurationException(string invalidParamName) :
             base($"Your {invalidParamName} setting is missing. Adjust the configuration first, see {InfoUrl}")
         {
         }

TLSharp.Tests/TLSharpTests.cs

@@ -231,6 +231,36 @@ namespace TLSharp.Tests
             Assert.IsTrue(resFile.bytes.Length > 0);
         }
 
+
+        [TestMethod]
+        public async Task DownloadFileFromWrongLocationTest()
+        {
+            var client = NewClient();
+
+            await client.ConnectAsync();
+
+            var result = await client.GetContactsAsync();
+
+            var user = result.users.lists
+                .Where(x => x.GetType() == typeof(TLUser))
+                .Cast<TLUser>()
+                .FirstOrDefault(x => x.id == 5880094);
+    
+            var photo = ((TLUserProfilePhoto)user.photo);
+            var photoLocation = (TLFileLocation) photo.photo_big;
+
+            var resFile = await client.GetFile(new TLInputFileLocation()
+            {
+                local_id = photoLocation.local_id,
+                secret = photoLocation.secret,
+                volume_id = photoLocation.volume_id
+            }, 1024);
+
+            var res = await client.GetUserDialogsAsync(); 
+
+            Assert.IsTrue(resFile.bytes.Length > 0);
+        }
+
         [TestMethod]
         public async Task SignUpNewUser()
         {