fix(grok): 完善按模型视频价格矩阵

backend/internal/pkg/xai/models.go

@@ -299,12 +299,10 @@ func ResolveDefaultTextModel(model string, defaultText ...string) string {
 func CanonicalImagineVideoModel(model string) string {
 	m := strings.ToLower(StripGrokProviderPrefix(model))
 	switch {
-	case m == "" || m == DefaultImagineVideoModel:
+	case m == "" || m == DefaultImagineVideoModel || m == "grok-imagine-video-preview":
 		return DefaultImagineVideoModel
 	case strings.HasPrefix(m, "grok-imagine-video-1.5") || m == "grok-video-1.5":
 		return DefaultImagineVideo15Model
-	case strings.HasPrefix(m, "grok-imagine-video"):
-		return DefaultImagineVideoModel
 	default:
 		return m
 	}

backend/internal/pkg/xai/models_test.go

@@ -44,6 +44,7 @@ func TestCanonicalImagineVideoModel(t *testing.T) {
 	require.Equal(t, DefaultImagineVideo15Model, CanonicalImagineVideoModel("grok-imagine-video-1.5"))
 	require.Equal(t, DefaultImagineVideo15Model, CanonicalImagineVideoModel("grok-imagine-video-1.5-preview"))
 	require.Equal(t, DefaultImagineVideo15Model, CanonicalImagineVideoModel("xai/grok-video-1.5"))
+	require.Equal(t, "grok-imagine-video-2", CanonicalImagineVideoModel("grok-imagine-video-2"))
 }
 
 func TestIsGrokModelID(t *testing.T) {

backend/internal/service/video_billing.go

@@ -18,14 +18,18 @@ func CanonicalGrokImagineVideoPriceFamily(model string) string {
 	if model == "" {
 		return ""
 	}
-	// Prefer shared xAI helper when available.
+	// Prefer shared xAI helper for known aliases. Keep future native Imagine
+	// models distinct so operators can assign them independent prices.
 	if c := xai.CanonicalImagineVideoModel(model); c != "" {
-		switch {
-		case strings.HasPrefix(c, "grok-imagine-video-1.5"):
+		switch c {
+		case xai.DefaultImagineVideo15Model:
 			return VideoPriceFamilyGrokImagineVideo15
-		case strings.HasPrefix(c, "grok-imagine-video"):
+		case xai.DefaultImagineVideoModel:
 			return VideoPriceFamilyGrokImagineVideo
 		}
+		if strings.HasPrefix(c, "grok-imagine-video-") {
+			return c
+		}
 	}
 	m := strings.ToLower(strings.TrimSpace(model))
 	for _, prefix := range []string{"xai/", "x-ai/", "grok/"} {
@@ -38,8 +42,8 @@ func CanonicalGrokImagineVideoPriceFamily(model string) string {
 	case m == "grok-imagine-video-1.5" || m == "grok-imagine-video-1.5-preview" ||
 		m == "grok-video-1.5" || strings.Contains(m, "video-1.5"):
 		return VideoPriceFamilyGrokImagineVideo15
-	case m == "grok-imagine-video" || m == "grok-video" || m == "grok-video-latest" ||
-		strings.HasPrefix(m, "grok-imagine-video") || strings.HasPrefix(m, "grok-video"):
+	case m == "grok-imagine-video" || m == "grok-imagine-video-preview" ||
+		m == "grok-video" || m == "grok-video-latest":
 		return VideoPriceFamilyGrokImagineVideo
 	default:
 		return ""
@@ -112,15 +116,5 @@ func LookupVideoModelPrice(prices map[string]map[string]float64, model, resoluti
 		p := price
 		return &p
 	}
-	for _, candidate := range []string{
-		VideoBillingResolution1080P,
-		VideoBillingResolution720P,
-		VideoBillingResolution480P,
-	} {
-		if price, ok := tierPrices[candidate]; ok {
-			p := price
-			return &p
-		}
-	}
 	return nil
 }

backend/internal/service/video_billing_test.go

@@ -12,6 +12,8 @@ func TestCanonicalGrokImagineVideoPriceFamily(t *testing.T) {
 	require.Equal(t, VideoPriceFamilyGrokImagineVideo15, CanonicalGrokImagineVideoPriceFamily("grok-imagine-video-1.5"))
 	require.Equal(t, VideoPriceFamilyGrokImagineVideo15, CanonicalGrokImagineVideoPriceFamily("grok-imagine-video-1.5-preview"))
 	require.Equal(t, VideoPriceFamilyGrokImagineVideo15, CanonicalGrokImagineVideoPriceFamily("xai/grok-video-1.5"))
+	require.Equal(t, "grok-imagine-video-2", CanonicalGrokImagineVideoPriceFamily("grok-imagine-video-2"))
+	require.Equal(t, "grok-imagine-video-2", CanonicalGrokImagineVideoPriceFamily("xai/grok-imagine-video-2"))
 }
 
 func TestNormalizeAndLookupVideoModelPrices(t *testing.T) {
@@ -19,11 +21,13 @@ func TestNormalizeAndLookupVideoModelPrices(t *testing.T) {
 	raw := map[string]map[string]float64{
 		"grok-imagine-video-1.5-preview": {"480p": 0.08, "720p": 0.14},
 		"grok-imagine-video":             {"480p": 0.05},
+		"grok-imagine-video-2":           {"1080p": 0.4},
 	}
 	norm := NormalizeVideoModelPrices(raw)
 	require.NotNil(t, norm)
 	require.Contains(t, norm, VideoPriceFamilyGrokImagineVideo15)
 	require.Contains(t, norm, VideoPriceFamilyGrokImagineVideo)
+	require.Contains(t, norm, "grok-imagine-video-2")
 
 	p15 := LookupVideoModelPrice(norm, "grok-imagine-video-1.5", "480p")
 	require.NotNil(t, p15)
@@ -32,7 +36,29 @@ func TestNormalizeAndLookupVideoModelPrices(t *testing.T) {
 	pBase := LookupVideoModelPrice(norm, "grok-imagine-video", "480p")
 	require.NotNil(t, pBase)
 	require.InDelta(t, 0.05, *pBase, 1e-9)
+	// A missing model-specific tier must fall back to the flat tier price,
+	// rather than borrowing another model-specific resolution.
+	require.Nil(t, LookupVideoModelPrice(norm, "grok-imagine-video", "720p"))
+
+	p2 := LookupVideoModelPrice(norm, "grok-imagine-video-2", "1080p")
+	require.NotNil(t, p2)
+	require.InDelta(t, 0.4, *p2, 1e-9)
 
 	// Unmatched model → nil (caller falls back to flat columns / defaults).
 	require.Nil(t, LookupVideoModelPrice(norm, "unknown-model", "480p"))
 }
+
+func TestVideoModelPriceMissingTierFallsBackToFlatTierPrice(t *testing.T) {
+	t.Parallel()
+	flat720P := 0.7
+	service := &BillingService{}
+
+	result := service.CalculateVideoCost("grok-imagine-video", "720p", 1, 1, &VideoPriceConfig{
+		Price720P: &flat720P,
+		ModelPrices: map[string]map[string]float64{
+			VideoPriceFamilyGrokImagineVideo: {VideoBillingResolution480P: 0.05},
+		},
+	}, 1)
+
+	require.InDelta(t, flat720P, result.TotalCost, 1e-9)
+}