feat(esgallery): mark stacks as processed

goes/esgallery/events.go

@@ -20,6 +20,11 @@ const (
 	Cleared         = "esgallery.cleared"
 )
 
+// Non-aggregate events
+const (
+	StackProcessed = "esgallery.stack_processed"
+)
+
 // ProcessorTriggerEvents are the events that can trigger a [*Processor].
 var ProcessorTriggerEvents = []string{
 	StackAdded,

goes/esgallery/gallery.go

@@ -7,6 +7,7 @@ import (
 	"github.com/modernice/media-entity/gallery"
 	"github.com/modernice/media-entity/image"
 	"github.com/modernice/media-entity/internal/slicex"
+	"golang.org/x/exp/slices"
 )
 
 // Target is an event-sourced aggregate that acts as a gallery.
@@ -40,7 +41,15 @@ type ID = gallery.ID
 type Gallery[StackID, ImageID ID, T Target] struct {
 	*gallery.Base[StackID, ImageID]
 
-	target T
+	target          T
+	processedStacks []StackID
+}
+
+// ProcessedStacks returns ids of the stacks that have been processed by a post-processor.
+func (g *Gallery[StackID, ImageID, T]) ProcessedStacks() []StackID {
+	out := make([]StackID, len(g.processedStacks))
+	copy(out, g.processedStacks)
+	return out
 }
 
 // New returns a new [*Gallery] that applies events and commands to the provided
@@ -74,6 +83,7 @@ func New[StackID, ImageID ID, T Target](target T) *Gallery[StackID, ImageID, T]
 	event.ApplyWith(target, g.untag, StackUntagged)
 	event.ApplyWith(target, g.sort, Sorted)
 	event.ApplyWith(target, g.clear, Cleared)
+	event.ApplyWith(target, g.stackProcessed, StackProcessed)
 
 	command.ApplyWith(target, func(load addStack[StackID, ImageID]) error {
 		_, err := g.NewStack(load.StackID, load.Image)
@@ -419,3 +429,14 @@ func (g *Gallery[StackID, ImageID, T]) Clear() {
 func (g *Gallery[StackID, ImageID, T]) clear(event.Of[struct{}]) {
 	g.Base.Clear()
 }
+
+// MarkAsProcessed marks a [gallery.Stack] as being processed by a post-processor.
+func (g *Gallery[StackID, ImageID, T]) MarkAsProcessed(stackID StackID) {
+	if !slices.Contains(g.ProcessedStacks(), stackID) {
+		aggregate.Next(g.target, StackProcessed, stackID)
+	}
+}
+
+func (g *Gallery[StackID, ImageID, T]) stackProcessed(evt event.Of[StackID]) {
+	g.processedStacks = append(g.processedStacks, evt.Data())
+}

goes/esgallery/processor.go

@@ -97,6 +97,9 @@ type ProcessableGallery[StackID, ImageID ID] interface {
 
 	// Tag adds tags to a [gallery.Stack].
 	Tag(StackID, ...string) (gallery.Stack[StackID, ImageID], error)
+
+	// MarkAsProcessed marks a [gallery.Stack] as being processed by a post-processor.
+	MarkAsProcessed(StackID)
 }
 
 // WasProcessed returns whether the given [gallery.Stack] was processed by a [*PostProcessor].
@@ -153,6 +156,8 @@ func (r ProcessorResult[StackID, ImageID]) Apply(g ProcessableGallery[StackID, I
 		}
 	}
 
+	g.MarkAsProcessed(r.StackID)
+
 	return nil
 }
 

goes/esgallery/processor_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/modernice/media-entity/internal/testx"
 	imgtools "github.com/modernice/media-tools/image"
 	"golang.org/x/exp/maps"
+	"golang.org/x/exp/slices"
 )
 
 func TestProcessor_Process(t *testing.T) {
@@ -435,4 +436,10 @@ func testProcessorResult(
 	if len(storage.Files()) != 4 {
 		t.Fatalf("expected 4 files in storage; got %d\n%s", len(storage.Files()), maps.Keys(storage.Files()))
 	}
+
+	if result.Applied {
+		if !slices.Contains(g.ProcessedStacks(), stack.ID) {
+			t.Fatalf("expected ProcessedStacks() to contain stack %s\n%v", stack.ID, g.ProcessedStacks())
+		}
+	}
 }