Implement InterceptCompletionAsync for GetRequest.

Fix SubsequentRequest functionality in LoadRequest.
Resolve file information parsing issues in GetRequest partial downloads.
Fix exception handling for Append mode in LoadRequest.
Address chunk merging issues in LoadRequest.
Update `Shard.Requests` to version 2.2.1.
Update unit tests

Author: Meyn

DownloadAssistant/Base/HttpGet.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Diagnostics;
+using System.Diagnostics;
 using System.Net.Http.Headers;
 
 namespace DownloadAssistant.Base

DownloadAssistant/DownloadAssistant.csproj

@@ -10,7 +10,7 @@
     <PackageProjectUrl></PackageProjectUrl>
     <PackageIcon>logo.png</PackageIcon>
     <PackageReadmeFile>README.md</PackageReadmeFile>
-    <Version>1.0.5</Version>
+    <Version>1.0.6</Version>
     <GenerateDocumentationFile>True</GenerateDocumentationFile>
     <Description>A free to use library as a download manager.
 Includes retry, priority, cancel, etc.. function.
@@ -26,7 +26,13 @@ Features:
     <PackageRequireLicenseAcceptance>True</PackageRequireLicenseAcceptance>
     <Company>Shard</Company>
     <Authors>Meyn</Authors>
-    <PackageReleaseNotes>Update Shard.Requests to 2.2.0</PackageReleaseNotes>
+    <PackageReleaseNotes>Implement InterceptCompletionAsync for GetRequest.
+Fix SubsequentRequest functionality in LoadRequest.
+Resolve file information parsing issues in GetRequest partial downloads.
+Fix exception handling for Append mode in LoadRequest.
+Address chunk merging issues in LoadRequest.
+Update `Shard.Requests` to version 2.2.1.
+Update unit tests</PackageReleaseNotes>
     <RepositoryUrl>https://github.com/TypNull/DownloadAssistant</RepositoryUrl>
   </PropertyGroup>
 
@@ -46,7 +52,7 @@ Features:
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Shard.Requests" Version="2.2.0" />
+    <PackageReference Include="Shard.Requests" Version="2.2.1" />
   </ItemGroup>
 
   <ItemGroup>

DownloadAssistant/Options/GetRequestOptions.cs

@@ -126,6 +126,11 @@ public long? MaxByte
         /// </value>
         public Notify<GetRequest>? InfosFetched { get; init; }
 
+        /// <summary>
+        /// Gets or sets a function that intercepts the completion of the request, allowing for custom asynchronous logic to modify or prevent the completion.
+        /// </summary>
+        public Func<GetRequest, Task>? InterceptCompletionAsync { get; set; }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="GetRequestOptions"/> class.
         /// </summary>
@@ -146,6 +151,7 @@ protected GetRequestOptions(GetRequestOptions options) : base(options)
             MinByte = options.MinByte;
             MaxByte = options.MaxByte;
             SupportsHeadRequest = options.SupportsHeadRequest;
+            InterceptCompletionAsync = options.InterceptCompletionAsync;
             Progress = options.Progress;
             Range = options.Range;
             InfosFetched = options.InfosFetched;

DownloadAssistant/Requests/GetRequest.cs

@@ -141,19 +141,14 @@ public async Task RunToCompleatedAsync()
             {
                 await Task;
                 _progress.Report(1f);
-                SynchronizationContext.Post(delegate (object? o)
-                {
-                    Options.RequestCompleated?.Invoke((GetRequest)o!, FilePath);
-                }, this);
-
+                SynchronizationContext.Post((o) => Options.RequestCompleated?.Invoke((GetRequest)o!, FilePath), this);
             }
         }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpGet"/> class that holds the HTTP information.
         /// </summary>
-        private void SetHttpGet()
-        => _httpGet = new(GetPresetRequestMessage(new(HttpMethod.Get, Url)), Options.SupportsHeadRequest)
+        private void SetHttpGet() => _httpGet = new(GetPresetRequestMessage(new(HttpMethod.Get, Url)), Options.SupportsHeadRequest)
         {
             Token = Token,
             Range = Range,
@@ -173,12 +168,15 @@ protected override async Task<RequestReturn> RunRequestAsync()
                 result = await LoadAsync();
                 result.FailedReturn?.Dispose();
                 if (State == RequestState.Running && result.Successful)
+                {
                     _progress.Report(1f);
+                    await (Options.InterceptCompletionAsync?.Invoke(this) ?? Task.CompletedTask);
+                }
             }
             catch (Exception ex)
             {
                 AddException(ex);
-                Debug.Assert(true, ex.Message);
+                Debug.Assert(false, ex.Message);
             }
 
             return result;
@@ -198,7 +196,7 @@ private async Task<RequestReturn> LoadAsync()
                 return new(false, FilePath, res);
             bool noBytesWritten = BytesWritten <= 0;
 
-            if (noBytesWritten)
+            if (string.IsNullOrEmpty(ContentName))
                 SetFileInfo(res);
 
             if (IsFinished())
@@ -247,7 +245,6 @@ private async Task<HttpResponseMessage> ReloadActions(HttpResponseMessage res, b
                 PartialContentLength = null;
             }
 
-
             return res;
         }
 
@@ -283,11 +280,10 @@ private void SetFileInfo(HttpResponseMessage res)
                     break;
                 case WriteMode.AppendOrTruncate:
                     LoadWrittenBytes();
-                    if (BytesWritten > ContentLength)
-                    {
-                        IOManager.Create(FilePath);
-                        BytesWritten = 0;
-                    }
+                    if (BytesWritten <= ContentLength)
+                        break;
+                    IOManager.Create(FilePath);
+                    BytesWritten = 0;
                     break;
                 case WriteMode.Append:
                     LoadWrittenBytes();
@@ -299,7 +295,6 @@ private void SetFileInfo(HttpResponseMessage res)
                     }
                     break;
             }
-
             Options.InfosFetched?.Invoke(this);
         }
 

DownloadAssistant/Requests/LoadRequest.cs

@@ -180,11 +180,11 @@ private void CreateRequest()
                 _chunkHandler.Add(CreateChunk(0, options));
 
                 Task.Run(() =>
-                {
-                    for (int i = 1; i < Options.Chunks; i++)
-                        _chunkHandler.Add(CreateChunk(i, options));
-                    AutoStart();
-                });
+                    {
+                        for (int i = 1; i < Options.Chunks; i++)
+                            _chunkHandler.Add(CreateChunk(i, options));
+                        AutoStart();
+                    });
                 return;
             }
 
@@ -194,7 +194,8 @@ private void CreateRequest()
                 RequestFailed = OnFailure,
                 SpeedReporter = Options.CreateSpeedReporter ? new() { Timeout = Options.SpeedReporterTimeout } : null,
                 RequestStarted = Options.RequestStarted,
-                RequestCompleated = OnCompletion,
+                SubsequentRequest = Options.SubsequentRequest,
+                InterceptCompletionAsync = OnCompletionAsync
             };
 
             InnerRequest = new GetRequest(Url, options);
@@ -215,8 +216,8 @@ private GetRequest CreateChunk(int index, GetRequestOptions options)
                 Range = new LoadRange(new Index(index), Options.Chunks),
                 SpeedReporter = Options.CreateSpeedReporter ? new() { Timeout = Options.SpeedReporterTimeout } : null,
                 Filename = $"{(string.IsNullOrWhiteSpace(Options.Filename) ? "*.*" : Options.Filename)}.{1 + index}_chunk",
-                RequestCompleated = OnCompletion,
                 RequestFailed = OnFailure,
+                InterceptCompletionAsync = OnCompletionAsync
             };
             if (index == 0)
                 options.RequestStarted += Options.RequestStarted;
@@ -263,7 +264,6 @@ private void OnInfosFetched(GetRequest? request)
             Filename = request.ContentName;
             try
             {
-
                 if (IsChunked)
                 {
                     _chunkHandler.SetInfos(request);
@@ -276,7 +276,6 @@ private void OnInfosFetched(GetRequest? request)
                         return;
                 }
 
-
                 SynchronizationContext.Post((o) => Options.InfosFetched?.Invoke((LoadRequest)o!), this);
                 ExcludedExtensions(request.ContentExtension);
             }
@@ -315,7 +314,6 @@ private void CreatePlaceholderFile(GetRequest request)
                     break;
                 case WriteMode.Overwrite:
                     IOManager.Create(Destination);
-
                     _writeMode = WriteMode.AppendOrTruncate;
                     break;
                 case WriteMode.AppendOrTruncate:
@@ -365,17 +363,20 @@ private async void CreatePlaceholderFiles(GetRequest request)
                 case WriteMode.Append:
                     if (File.Exists(Destination) && new FileInfo(Destination).Length > 0)
                     {
-                        AddException(new FileLoadException($"The file {Filename} at {Destination} already exists. Please change the WriteMode or delete the file."));
+                        AddException(new FileLoadException($"The file '{Filename}' already exists at '{Destination}'. Resolve by changing WriteMode, deleting the file, or avoiding chunked requests."));
                         OnFailure(this, null);
                         break;
                     }
                     if (!File.Exists(TempDestination))
                         break;
-                    if (new FileInfo(TempDestination).Length < (request.FullContentLength ?? (request.PartialContentLength * Options.Chunks)))
+                    long appendByteLength = new FileInfo(TempDestination).Length;
+                    if (appendByteLength > (request.FullContentLength ?? (request.PartialContentLength * Options.Chunks)))
                     {
                         AddException(new FileLoadException($"The file specified in {TempDestination} has exceeded the expected filesize of the actual downloaded file. Please adjust the WriteMode."));
                         OnFailure(this, null);
+                        break;
                     }
+                    await _chunkHandler.TrySetBytesAsync(appendByteLength);
                     break;
                 case WriteMode.AppendOrTruncate:
                     IOManager.Create(Destination);
@@ -411,25 +412,29 @@ private void ExcludedExtensions(string contentExtension)
         /// Handles the completion of the request.
         /// </summary>
         /// <param name="request">The <see cref="IRequest"/> instance that has completed.</param>
-        /// <param name="_">This parameter is not used.</param>
         /// <remarks>
         /// This method handles the completion of the request. If the request is chunked, it starts merging the chunks. If the request is not chunked, it moves the temporary file to the destination.
         /// </remarks>
-        private async void OnCompletion(IRequest? request, string? _)
+        private async Task OnCompletionAsync(IRequest? request)
         {
             if (request == null)
                 return;
             bool canMove = false;
             if (IsChunked)
             {
-                if (Options.MergeWhileProgress || _chunkHandler.Requests.All(request => request.State == RequestState.Compleated))
+                _chunkHandler.MarkChunkAsCompleted((GetRequest)request);
+                if (Options.MergeWhileProgress || _chunkHandler.AllCompleted)
                     canMove = await _chunkHandler.StartMergeTo(TempDestination);
             }
             else
                 canMove = true;
 
             if (canMove)
+            {
+                if (Options.SubsequentRequest != null)
+                    ((GetRequest)request).TrySetSubsequentRequest(Options.SubsequentRequest);
                 TempToDestination();
+            }
         }
 
         /// <summary>
@@ -522,12 +527,11 @@ public override void Cancel()
         /// <summary>
         /// Releases all resources used by the <see cref="LoadRequest"/>.
         /// </summary>
-#pragma warning disable CA1816
         public override void Dispose()
-#pragma warning restore CA1816
         {
             InnerRequest.Dispose();
             base.Dispose();
+            GC.SuppressFinalize(this);
         }
     }
 }