Respect provider rate limits and preserve bank connections on throttling

internal/app/reclassify.go

@@ -70,7 +70,7 @@ func (a *App) Preview(ctx context.Context, r PreviewRequest) (Preview, error) {
 	}
 	a.mu.Lock()
 	s, err := a.snapshot(ctx)
-	client := a.classifier
+	client := a.classifier.WithModel(r.Model)
 	a.mu.Unlock()
 	if err != nil {
 		return Preview{}, err
@@ -78,7 +78,6 @@ func (a *App) Preview(ctx context.Context, r PreviewRequest) (Preview, error) {
 	if r.Revision != s.Revision {
 		return Preview{}, errors.New("revision conflict: reload before analysing")
 	}
-	client.Model = r.Model
 	p := Preview{ID: domain.NewID("preview"), Revision: s.Revision, Changes: []Change{}, Errors: []ClassificationError{}, created: time.Now()}
 	baseMerchants := len(s.Data.Merchants)
 	for _, t := range s.Data.Transactions {
@@ -90,6 +89,9 @@ func (a *App) Preview(ctx context.Context, r PreviewRequest) (Preview, error) {
 		}
 		p.Analysed++
 		proposal, e := client.Classify(ctx, t.Facts, s.Data, true)
+		if err = ctx.Err(); err != nil {
+			return Preview{}, err
+		}
 		if e != nil {
 			p.Errors = append(p.Errors, ClassificationError{t.Facts.ID, e.Error()})
 			continue