From 8fd93bfd2923a35f25ae35f9cade3a3449737765 Mon Sep 17 00:00:00 2001
From: 134 <a134@134deMacBook-Pro.local>
Date: Thu, 2 Jul 2026 00:15:45 +0800
Subject: [PATCH] fix: keep fal as scale adjust fallback

---
 app/api/canvas/local-edit/route.ts | 19 +++++++++++++++--
 lib/canvas/generate-image.ts       | 33 +++++++++++++++++++++++-------
 2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/app/api/canvas/local-edit/route.ts b/app/api/canvas/local-edit/route.ts
index ca9935cec..9db793cde 100644
--- a/app/api/canvas/local-edit/route.ts
+++ b/app/api/canvas/local-edit/route.ts
@@ -307,6 +307,21 @@ function getScaleAdjustProviderPriority(providerType: string) {
   }
 }
 
+function getScaleAdjustModelHealthPenalty(
+  healthStatus: string | null | undefined
+) {
+  if (healthStatus === "degraded") return 25;
+  if (healthStatus === "auto_disabled") return 200;
+  return 0;
+}
+
+function getScaleAdjustCandidatePriority(entry: AiModelWithProviderForSelection) {
+  return (
+    getScaleAdjustProviderPriority(entry.provider.type) +
+    getScaleAdjustModelHealthPenalty(entry.model.healthStatus)
+  );
+}
+
 function isScaleAdjustUsableImageEditModel(
   entry: AiModelWithProviderForSelection | null | undefined
 ) {
@@ -321,8 +336,8 @@ function compareScaleAdjustProviderCandidates(
   right: AiModelWithProviderForSelection,
   preferredModelRef: string
 ) {
-  const leftPriority = getScaleAdjustProviderPriority(left.provider.type);
-  const rightPriority = getScaleAdjustProviderPriority(right.provider.type);
+  const leftPriority = getScaleAdjustCandidatePriority(left);
+  const rightPriority = getScaleAdjustCandidatePriority(right);
   if (leftPriority !== rightPriority) return leftPriority - rightPriority;
 
   const leftDedicated = isScaleAdjustDedicatedDetailModel(left);
diff --git a/lib/canvas/generate-image.ts b/lib/canvas/generate-image.ts
index 9d284e099..7dfbe27f7 100644
--- a/lib/canvas/generate-image.ts
+++ b/lib/canvas/generate-image.ts
@@ -1613,6 +1613,21 @@ function getCanvasScaleAdjustProviderFailoverPriority(providerType: string) {
   }
 }
 
+function getCanvasScaleAdjustHealthPenalty(
+  healthStatus: string | null | undefined
+) {
+  if (healthStatus === "degraded") return 25;
+  if (healthStatus === "auto_disabled") return 200;
+  return 0;
+}
+
+function getCanvasScaleAdjustFailoverPriority(item: CanvasModelWithProvider) {
+  return (
+    getCanvasScaleAdjustProviderFailoverPriority(item.provider.type) +
+    getCanvasScaleAdjustHealthPenalty(item.model.healthStatus)
+  );
+}
+
 interface CanvasImageGenConfig {
   maxImages?: number;
   supports1K?: boolean;
@@ -1788,7 +1803,15 @@ function findCanvasFailoverModel(params: {
     .filter(Boolean);
 
   const isUsableFallback = (item: CanvasModelWithProvider) => {
-    if (!item.model.isEnabled || item.model.isSubModel || item.model.excludeFromFailover) {
+    const isSameNameScaleAdjustFallback =
+      params.preferLowCostSameNameProviders &&
+      scoreModelNameSimilarity(params.selectedModel, item) >=
+        CANVAS_FAILOVER_SAME_NAME_THRESHOLD;
+    if (
+      !item.model.isEnabled ||
+      item.model.isSubModel ||
+      (item.model.excludeFromFailover && !isSameNameScaleAdjustFallback)
+    ) {
       return false;
     }
     if (!item.model.supportsImageGen) return false;
@@ -1832,12 +1855,8 @@ function findCanvasFailoverModel(params: {
         leftSameName &&
         rightSameName
       ) {
-        const leftPriority = getCanvasScaleAdjustProviderFailoverPriority(
-          left.item.provider.type
-        );
-        const rightPriority = getCanvasScaleAdjustProviderFailoverPriority(
-          right.item.provider.type
-        );
+        const leftPriority = getCanvasScaleAdjustFailoverPriority(left.item);
+        const rightPriority = getCanvasScaleAdjustFailoverPriority(right.item);
         if (leftPriority !== rightPriority) return leftPriority - rightPriority;
         if (right.nameSimilarity !== left.nameSimilarity) {
           return right.nameSimilarity - left.nameSimilarity;