add ai feature

internal/ai/flow/json.go

@@ -0,0 +1,50 @@
+package flow
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+)
+
+// Suggestion represents a single rename mapping emitted by the Genkit flow.
+type Suggestion struct {
+	Original  string `json:"original"`
+	Suggested string `json:"suggested"`
+}
+
+// Output wraps the list of suggestions returned by the flow.
+type Output struct {
+	Suggestions []Suggestion `json:"suggestions"`
+}
+
+var (
+	errEmptyResponse      = errors.New("genkit flow returned empty response")
+	errMissingSuggestions = errors.New("genkit flow response missing suggestions")
+)
+
+// ParseOutput converts the raw JSON payload into a structured Output.
+func ParseOutput(raw []byte) (Output, error) {
+	if len(raw) == 0 {
+		return Output{}, errEmptyResponse
+	}
+
+	var out Output
+	if err := json.Unmarshal(raw, &out); err != nil {
+		return Output{}, fmt.Errorf("failed to decode genkit output: %w", err)
+	}
+
+	if len(out.Suggestions) == 0 {
+		return Output{}, errMissingSuggestions
+	}
+
+	return out, nil
+}
+
+// MarshalInput serialises the flow input for logging or replay.
+func MarshalInput(input any) ([]byte, error) {
+	buf, err := json.Marshal(input)
+	if err != nil {
+		return nil, fmt.Errorf("failed to encode genkit input: %w", err)
+	}
+	return buf, nil
+}