[backend/api] Add support for creating, forwarding & resolving reports (ISH-116)

Iceshrimp.Backend/Controllers/Web/ModerationController.cs

@@ -20,7 +20,8 @@ public class ModerationController(
 	DatabaseContext db,
 	NoteService noteSvc,
 	UserService userSvc,
-	ReportRenderer reportRenderer
+	ReportRenderer reportRenderer,
+	ReportService reportSvc
 ) : ControllerBase
 {
 	[HttpPost("notes/{id}/delete")]
@@ -101,4 +102,38 @@ public class ModerationController(
 
 		return await reportRenderer.RenderManyAsync(reports);
 	}
+
+	[HttpPost("reports/{id}/resolve")]
+	[ProducesResults(HttpStatusCode.OK)]
+	[ProducesErrors(HttpStatusCode.NotFound)]
+	public async Task ResolveReport(string id)
+	{
+		var report = await db.Reports.FirstOrDefaultAsync(p => p.Id == id)
+		             ?? throw GracefulException.NotFound("Report not found");
+
+		report.Resolved = true;
+		await db.SaveChangesAsync();
+	}
+
+	[HttpPost("reports/{id}/forward")]
+	[ProducesResults(HttpStatusCode.OK)]
+	[ProducesErrors(HttpStatusCode.BadRequest, HttpStatusCode.NotFound)]
+	public async Task ForwardReport(string id, [FromBody] NoteReportRequest? request)
+	{
+		var report = await db.Reports
+		                     .Include(p => p.TargetUser)
+		                     .Include(p => p.Notes)
+		                     .FirstOrDefaultAsync(p => p.Id == id)
+		             ?? throw GracefulException.NotFound("Report not found");
+
+		if (report.TargetUserHost == null)
+			throw GracefulException.BadRequest("Cannot forward report to local instance");
+		if (report.Forwarded)
+			return;
+
+		await reportSvc.ForwardReportAsync(report, request?.Comment);
+
+		report.Forwarded = true;
+		await db.SaveChangesAsync();
+	}
 }

Iceshrimp.Backend/Controllers/Web/NoteController.cs

@@ -30,7 +30,8 @@ public class NoteController(
 	UserRenderer userRenderer,
 	CacheService cache,
 	BiteService biteSvc,
-	PollService pollSvc
+	PollService pollSvc,
+	ReportService reportSvc
 ) : ControllerBase
 {
 	private static readonly AsyncKeyedLocker<string> KeyedLocker = new(o =>
@@ -645,4 +646,18 @@ public class NoteController(
 
 		return await noteRenderer.RenderOne(note, user);
 	}
+
+	[HttpPost("{id}/report")]
+	[Authenticate]
+	[Authorize]
+	[ProducesResults(HttpStatusCode.OK)]
+	[ProducesErrors(HttpStatusCode.NotFound)]
+	public async Task ReportNote(string id, [FromBody] NoteReportRequest request)
+	{
+		var user = HttpContext.GetUserOrFail();
+		var note = await db.Notes.Include(p => p.User).EnsureVisibleFor(user).FirstOrDefaultAsync(p => p.Id == id)
+		           ?? throw GracefulException.NotFound("Note not found");
+
+		await reportSvc.CreateReportAsync(user, note.User, [note], request.Comment);
+	}
 }

Iceshrimp.Backend/Core/Federation/ActivityPub/ActivityHandlerService.cs

@@ -28,7 +28,8 @@ public class ActivityHandlerService(
 	FollowupTaskService followupTaskSvc,
 	EmojiService emojiSvc,
 	EventService eventSvc,
-	RelayService relaySvc
+	RelayService relaySvc,
+	ReportService reportSvc
 ) : IScopedService
 {
 	public async Task PerformActivityAsync(ASActivity activity, string? inboxUserId, string? authenticatedUserId)
@@ -556,20 +557,7 @@ public class ActivityHandlerService(
 		if (noteMatches.Count != 0 && noteMatches.Any(p => p.User != userMatch))
 			throw GracefulException.UnprocessableEntity("Refusing to process ASFlag: note author mismatch");
 
-		var report = new Report
+		await reportSvc.CreateReportAsync(resolvedActor, userMatch, noteMatches, flag.Content ?? "");
-		{
-			Id             = IdHelpers.GenerateSnowflakeId(),
-			CreatedAt      = DateTime.UtcNow,
-			TargetUser     = userMatch,
-			TargetUserHost = userMatch.Host,
-			Reporter       = resolvedActor,
-			ReporterHost   = resolvedActor.Host,
-			Notes          = noteMatches,
-			Comment        = flag.Content ?? ""
-		};
-
-		db.Add(report);
-		await db.SaveChangesAsync();
 	}
 
 	private async Task UnfollowAsync(ASActor followeeActor, User follower)

Iceshrimp.Backend/Core/Federation/ActivityPub/ActivityRenderer.cs

@@ -240,19 +240,11 @@ public class ActivityRenderer(
 		To          = userRenderer.RenderLite(fallbackTo)
 	};
 
-	public ASFlag RenderFlag(User actor, IEnumerable<Note> notes, string comment) => new()
+	public ASFlag RenderFlag(User actor, User user, IEnumerable<Note> notes, string comment) => new()
 	{
 		Id      = GenerateActivityId(),
 		Actor   = userRenderer.RenderLite(actor),
-		Object  = notes.Select(noteRenderer.RenderLite).ToArray<ASObject>(),
+		Object  = notes.Select(noteRenderer.RenderLite).Prepend<ASObject>(userRenderer.RenderLite(user)).ToArray(),
-		Content = comment
-	};
-
-	public ASFlag RenderFlag(User actor, User user, string comment) => new()
-	{
-		Id      = GenerateActivityId(),
-		Actor   = userRenderer.RenderLite(actor),
-		Object  = [userRenderer.RenderLite(user)],
 		Content = comment
 	};
 }

Iceshrimp.Backend/Core/Services/ReportService.cs

@@ -0,0 +1,47 @@
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Database.Tables;
+using Iceshrimp.Backend.Core.Extensions;
+using Iceshrimp.Backend.Core.Helpers;
+
+namespace Iceshrimp.Backend.Core.Services;
+
+public class ReportService(
+	ActivityPub.ActivityDeliverService deliverSvc,
+	ActivityPub.ActivityRenderer activityRenderer,
+	SystemUserService sysUserSvc,
+	DatabaseContext db
+) : IScopedService
+{
+	public async Task ForwardReportAsync(Report report, string? comment)
+	{
+		if (report.TargetUser.IsLocalUser)
+			throw new Exception("Refusing to forward report to local instance");
+
+		var actor    = await sysUserSvc.GetInstanceActorAsync();
+		var activity = activityRenderer.RenderFlag(actor, report.TargetUser, report.Notes, comment ?? report.Comment);
+
+		var inbox = report.TargetUser.SharedInbox
+		            ?? report.TargetUser.Inbox
+		            ?? throw new Exception("Target user does not have inbox");
+
+		await deliverSvc.DeliverToAsync(activity, actor, inbox);
+	}
+
+	public async Task CreateReportAsync(User reporter, User target, IEnumerable<Note> notes, string comment)
+	{
+		var report = new Report
+		{
+			Id             = IdHelpers.GenerateSnowflakeId(),
+			CreatedAt      = DateTime.UtcNow,
+			TargetUser     = target,
+			TargetUserHost = target.Host,
+			Reporter       = reporter,
+			ReporterHost   = reporter.Host,
+			Notes          = notes.ToArray(),
+			Comment        = comment
+		};
+
+		db.Add(report);
+		await db.SaveChangesAsync();
+	}
+}

Iceshrimp.Shared/Schemas/Web/NoteReportRequest.cs

@@ -0,0 +1,6 @@
+namespace Iceshrimp.Shared.Schemas.Web;
+
+public class NoteReportRequest
+{
+	public required string Comment { get; set; }
+}