[FA-misc] Saga seems to work, fixed a UserNovelDataService bug

2026-01-28 12:11:06 -05:00
parent 579e05b853
commit ec967770d3
34 changed files with 1341 additions and 97 deletions
--- a/FictionArchive.Service.NovelService/Sagas/NovelImportSaga.cs
+++ b/FictionArchive.Service.NovelService/Sagas/NovelImportSaga.cs
@@ -0,0 +1,135 @@
+using FictionArchive.Service.Shared.Contracts.Events;
+using MassTransit;
+using NodaTime;
+
+namespace FictionArchive.Service.NovelService.Sagas;
+
+public class NovelImportSaga : MassTransitStateMachine<NovelImportSagaState>
+{
+    public State Importing { get; private set; } = null!;
+    public State Processing { get; private set; } = null!;
+    public State Completed { get; private set; } = null!;
+    public State Failed { get; private set; } = null!;
+
+    public Event<INovelImportRequested> NovelImportRequested { get; private set; } = null!;
+    public Event<INovelMetadataImported> NovelMetadataImported { get; private set; } = null!;
+    public Event<IChapterPullCompleted> ChapterPullCompleted { get; private set; } = null!;
+    public Event<IFileUploadRequestStatusUpdate> FileUploadStatusUpdate { get; private set; } = null!;
+    public Event<Fault<IChapterPullRequested>> ChapterPullFaulted { get; private set; } = null!;
+    public Event<Fault<IFileUploadRequestCreated>> FileUploadFaulted { get; private set; } = null!;
+
+    private readonly IClock _clock;
+
+    public NovelImportSaga(IClock clock)
+    {
+        _clock = clock;
+
+        InstanceState(x => x.CurrentState);
+
+        Event(() => NovelImportRequested, x => x.CorrelateById(ctx => ctx.Message.ImportId));
+        Event(() => NovelMetadataImported, x => x.CorrelateById(ctx => ctx.Message.ImportId));
+        Event(() => ChapterPullCompleted, x => x.CorrelateById(ctx => ctx.Message.ImportId));
+        Event(() => FileUploadStatusUpdate, x =>
+        {
+            x.CorrelateById(ctx => ctx.Message.ImportId ?? Guid.Empty);
+            x.OnMissingInstance(m => m.Discard());
+        });
+        Event(() => ChapterPullFaulted, x => x.CorrelateById(ctx => ctx.Message.Message.ImportId));
+        Event(() => FileUploadFaulted, x =>
+        {
+            x.CorrelateById(ctx => ctx.Message.Message.ImportId ?? Guid.Empty);
+            x.OnMissingInstance(m => m.Discard());
+        });
+
+        Initially(
+            When(NovelImportRequested)
+                .Then(ctx =>
+                {
+                    ctx.Saga.NovelUrl = ctx.Message.NovelUrl;
+                    ctx.Saga.StartedAt = _clock.GetCurrentInstant();
+                })
+                .TransitionTo(Importing)
+        );
+
+        During(Importing,
+            When(NovelMetadataImported)
+                .Then(ctx =>
+                {
+                    ctx.Saga.NovelId = ctx.Message.NovelId;
+                    ctx.Saga.ExpectedChapters = ctx.Message.ChaptersPendingPull;
+                })
+                .IfElse(
+                    ctx => ctx.Saga.ExpectedChapters == 0,
+                    thenBinder => thenBinder
+                        .Then(ctx => ctx.Saga.CompletedAt = _clock.GetCurrentInstant())
+                        .TransitionTo(Completed)
+                        .PublishAsync(ctx => ctx.Init<INovelImportCompleted>(new NovelImportCompleted(
+                            ctx.Saga.CorrelationId,
+                            ctx.Saga.NovelId,
+                            true,
+                            null))),
+                    elseBinder => elseBinder.TransitionTo(Processing)
+                )
+        );
+
+        During(Processing,
+            When(ChapterPullCompleted)
+                .Then(ctx =>
+                {
+                    ctx.Saga.CompletedChapters++;
+                    ctx.Saga.ExpectedImages += ctx.Message.ImagesQueued;
+                })
+                .If(ctx => IsComplete(ctx.Saga), ctx => ctx
+                    .Then(c => c.Saga.CompletedAt = _clock.GetCurrentInstant())
+                    .TransitionTo(Completed)
+                    .PublishAsync(c => c.Init<INovelImportCompleted>(new NovelImportCompleted(
+                        c.Saga.CorrelationId,
+                        c.Saga.NovelId,
+                        true,
+                        null)))),
+
+            When(FileUploadStatusUpdate)
+                .Then(ctx => ctx.Saga.CompletedImages++)
+                .If(ctx => IsComplete(ctx.Saga), ctx => ctx
+                    .Then(c => c.Saga.CompletedAt = _clock.GetCurrentInstant())
+                    .TransitionTo(Completed)
+                    .PublishAsync(c => c.Init<INovelImportCompleted>(new NovelImportCompleted(
+                        c.Saga.CorrelationId,
+                        c.Saga.NovelId,
+                        true,
+                        null)))),
+
+            When(ChapterPullFaulted)
+                .Then(ctx =>
+                {
+                    ctx.Saga.ErrorMessage = ctx.Message.Exceptions.FirstOrDefault()?.Message;
+                    ctx.Saga.CompletedAt = _clock.GetCurrentInstant();
+                })
+                .TransitionTo(Failed)
+                .PublishAsync(ctx => ctx.Init<INovelImportCompleted>(new NovelImportCompleted(
+                    ctx.Saga.CorrelationId,
+                    ctx.Saga.NovelId,
+                    false,
+                    ctx.Saga.ErrorMessage))),
+
+            When(FileUploadFaulted)
+                .Then(ctx =>
+                {
+                    ctx.Saga.ErrorMessage = ctx.Message.Exceptions.FirstOrDefault()?.Message;
+                    ctx.Saga.CompletedAt = _clock.GetCurrentInstant();
+                })
+                .TransitionTo(Failed)
+                .PublishAsync(ctx => ctx.Init<INovelImportCompleted>(new NovelImportCompleted(
+                    ctx.Saga.CorrelationId,
+                    ctx.Saga.NovelId,
+                    false,
+                    ctx.Saga.ErrorMessage)))
+        );
+
+        SetCompletedWhenFinalized();
+    }
+
+    private static bool IsComplete(NovelImportSagaState saga) =>
+        saga.CompletedChapters >= saga.ExpectedChapters &&
+        saga.CompletedImages >= saga.ExpectedImages;
+}