WeKnora deployment source with the reviewed wiki identity, summary and recovery fixes

internal/models/vlm/langfuse_wrapper.go

@@ -0,0 +1,72 @@
+package vlm
+
+import (
+	"context"
+
+	"github.com/Tencent/WeKnora/internal/tracing/langfuse"
+)
+
+// langfuseVLM wraps a VLM and reports each Predict call as a Langfuse
+// generation. The raw image bytes are NOT uploaded — Langfuse traces are
+// designed for text. We include image count and total byte size in the
+// metadata, plus the text prompt, which matches how Langfuse's own VLM
+// integrations report multimodal calls.
+type langfuseVLM struct {
+	inner VLM
+}
+
+func (l *langfuseVLM) GetModelName() string { return l.inner.GetModelName() }
+func (l *langfuseVLM) GetModelID() string   { return l.inner.GetModelID() }
+
+func (l *langfuseVLM) Predict(ctx context.Context, imgBytes [][]byte, prompt string) (string, error) {
+	mgr := langfuse.GetManager()
+	if !mgr.Enabled() {
+		return l.inner.Predict(ctx, imgBytes, prompt)
+	}
+
+	totalImgSize := 0
+	for _, b := range imgBytes {
+		totalImgSize += len(b)
+	}
+
+	genCtx, gen := mgr.StartGeneration(ctx, langfuse.GenerationOptions{
+		Name:  "vlm.predict",
+		Model: l.inner.GetModelName(),
+		Input: map[string]interface{}{
+			"prompt":      prompt,
+			"image_count": len(imgBytes),
+		},
+		Metadata: map[string]interface{}{
+			"model_id":          l.inner.GetModelID(),
+			"image_count":       len(imgBytes),
+			"image_bytes_total": totalImgSize,
+		},
+	})
+
+	result, err := l.inner.Predict(genCtx, imgBytes, prompt)
+
+	// VLMs don't return token usage; approximate prompt tokens for cost
+	// tracking in Langfuse (users can configure per-model pricing in the UI).
+	promptTokens := len([]rune(prompt))/4 + 1
+	outputTokens := len([]rune(result)) / 4
+	usage := &langfuse.TokenUsage{
+		Input:  promptTokens,
+		Output: outputTokens,
+		Total:  promptTokens + outputTokens,
+		Unit:   "TOKENS",
+	}
+
+	gen.Finish(result, usage, err)
+	return result, err
+}
+
+// wrapVLMLangfuse applies the Langfuse decorator when the manager is enabled.
+func wrapVLMLangfuse(v VLM, err error) (VLM, error) {
+	if err != nil || v == nil {
+		return v, err
+	}
+	if !langfuse.GetManager().Enabled() {
+		return v, nil
+	}
+	return &langfuseVLM{inner: v}, nil
+}