From 0808f34021ec2d8b4a6952e5763b04b989f56805 Mon Sep 17 00:00:00 2001
From: Your Name <your.email@example.com>
Date: Thu, 4 Jun 2026 10:07:00 +0800
Subject: [PATCH] fix: make detail scene prompt pack explicit

---
 app/(chat)/api/chat/_lib/detail-replacement.ts | 18 +++++++++++++++++-
 app/(chat)/api/chat/route.ts                   | 14 ++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/app/(chat)/api/chat/_lib/detail-replacement.ts b/app/(chat)/api/chat/_lib/detail-replacement.ts
index da5a7de3f..b8939af5b 100644
--- a/app/(chat)/api/chat/_lib/detail-replacement.ts
+++ b/app/(chat)/api/chat/_lib/detail-replacement.ts
@@ -2484,6 +2484,20 @@ export function buildAgentReplacementPrompt(params: {
           "如果参考图标题、标签或画面中出现可识别的外部品牌字样，不要保留该品牌名，不要换成相似字，不要生成伪 Logo；需要文字时只保留非品牌卖点语义或改成无品牌通用描述。",
         ]
       : [];
+  const normalizedBasePrompt = String(params.basePrompt || "").trim();
+  const promptPackInstructionLines =
+    params.modeType === "detail_replacement" &&
+    shouldApplyPromptPack &&
+    normalizedBasePrompt
+      ? [
+          "【必须生效的前置场景词包】",
+          normalizedBasePrompt,
+          isReferencePosterActionPlan
+            ? "执行优先级：前置场景词包必须改造图片框内旧背景、空间、软装、灯光、墙面、地面、摆件和产品场景；参考图只锁人物数量、围坐/试坐/承重动作、产品受力关系、版式、机位、文案层和图片框边界，不锁旧背景物件。"
+            : "执行优先级：前置场景词包必须改造图片框内旧背景、空间、软装、灯光、墙面、地面、摆件和产品场景；参考图只锁版式、机位、文字层、主体位置和图片框边界，不锁旧背景物件。",
+          "如果最终图仍大量保留参考图原背景物件、原空间陈设或只做轻微修饰，判定为失败；必须能明显看出已按前置场景词包重建。",
+        ]
+      : [];
 
   const scenePlanLines = params.scenePlan
     ? [
@@ -2559,6 +2573,7 @@ export function buildAgentReplacementPrompt(params: {
           `当前要处理第 ${params.referenceIndex + 1} / ${params.totalReferences} 张详情参考图：${params.referenceLabel}`,
           "【图片顺序规则】",
           ...imageOrderLines,
+          ...promptPackInstructionLines,
           ...scenePlanLines,
           ...marketplaceBrandRemovalLines,
           "你现在做的是‘仅替换产品’，不是重建场景，也不是重新设计整张详情图。",
@@ -2586,6 +2601,7 @@ export function buildAgentReplacementPrompt(params: {
           `当前要处理第 ${params.referenceIndex + 1} / ${params.totalReferences} 张详情参考图：${params.referenceLabel}`,
           "【图片顺序规则】",
           ...imageOrderLines,
+          ...promptPackInstructionLines,
           ...scenePlanLines,
           ...marketplaceBrandRemovalLines,
           "你现在做的是“详情参考图背景/场景图替换”，不是重新设计整张详情图。",
@@ -2711,7 +2727,7 @@ export function buildAgentReplacementPrompt(params: {
   }
 
   return [
-    params.modeType === "detail_replacement" && !shouldApplyPromptPack
+    params.modeType === "detail_replacement"
       ? ""
       : params.basePrompt,
     instructionLines.join("\n"),
diff --git a/app/(chat)/api/chat/route.ts b/app/(chat)/api/chat/route.ts
index dac7594b0..972d07224 100644
--- a/app/(chat)/api/chat/route.ts
+++ b/app/(chat)/api/chat/route.ts
@@ -3481,6 +3481,17 @@ export async function POST(request: Request) {
                 scenePlan: replacementExecutionPlan.scenePlan,
                 referenceGeometry,
               });
+              chatApiLogger.info("[Chat API] Direct detail replacement prompt assembled:", {
+                referenceIndex: referenceIndex + 1,
+                totalReferences: replacementReferences.length,
+                referenceLabel: reference.label,
+                pageKind: replacementExecutionPlan.scenePlan.pageKind,
+                generationRoute: replacementExecutionPlan.scenePlan.generationRoute,
+                promptPackPolicy: replacementExecutionPlan.scenePlan.promptPackPolicy,
+                basePromptChars: baseReplacementPrompt.length,
+                promptChars: replacementPrompt.length,
+                hasPromptPackBlock: replacementPrompt.includes("【必须生效的前置场景词包】"),
+              });
 
               try {
                 const result = await generateCanvasImage({
@@ -4279,6 +4290,9 @@ export async function POST(request: Request) {
                   pageKind: replacementExecutionPlan.scenePlan.pageKind,
                   generationRoute: replacementExecutionPlan.scenePlan.generationRoute,
                   promptPackPolicy: replacementExecutionPlan.scenePlan.promptPackPolicy,
+                  basePromptChars: baseReplacementPrompt.length,
+                  promptChars: replacementPrompt.length,
+                  hasPromptPackBlock: replacementPrompt.includes("【必须生效的前置场景词包】"),
                   sourceImageCount: sourceImageUrls.length,
                   generationAspectRatio,
                   imageOrder: {