fix(avatar): ground replies in recognized images

digital-avatar-app/backend/services/takeover_service.py

@@ -50,8 +50,15 @@ BOXIM_IMAGE_MESSAGE_TYPE = 1
 BOXIM_IMAGE_PROMPT = "请看看这张图片。"
 BOXIM_IMAGE_UNAVAILABLE_REPLY = "这张图片我暂时没看清，麻烦重新发送一张清晰的原图。"
 IMAGE_CONTEXT_LOOKBACK_SECONDS = 1800
+IMAGE_REFERENCE_LOOKBACK_SECONDS = 172_800
 MAX_RECENT_IMAGE_CONTEXTS = 3
 
+_IMAGE_REFERENCE_PATTERN = re.compile(
+    r"(?:图片|图像|照片|截图|这张图|刚才.{0,8}图|病例|病历|检查单|检验单|化验单|报告|影像|"
+    r"\b(?:image|photo|picture|screenshot|scan|report)\b)",
+    re.IGNORECASE,
+)
+
 
 def _utcnow() -> datetime:
     return datetime.utcnow()
@@ -129,6 +136,10 @@ def _event_prompt(event: TakeoverMessage) -> str:
     return ""
 
 
+def _references_recent_image(value: str) -> bool:
+    return bool(_IMAGE_REFERENCE_PATTERN.search(value or ""))
+
+
 class TakeoverService:
     """Poll BOXIM, honor the owner grace period, then generate and send one reply."""
 
@@ -693,8 +704,14 @@ class TakeoverService:
         event: TakeoverMessage,
         current_source_ids: list[str],
     ) -> list[TakeoverMessage]:
-        """Recover a recent image that an older deployment recorded without a task."""
-        threshold = event.send_time - timedelta(seconds=IMAGE_CONTEXT_LOOKBACK_SECONDS)
+        """Recover missed images, or reuse a referenced image from the last two days."""
+        references_image = _references_recent_image(event.content)
+        lookback_seconds = (
+            IMAGE_REFERENCE_LOOKBACK_SECONDS
+            if references_image
+            else IMAGE_CONTEXT_LOOKBACK_SECONDS
+        )
+        threshold = event.send_time - timedelta(seconds=lookback_seconds)
         candidates = (
             db.query(TakeoverMessage)
             .filter(
@@ -714,7 +731,15 @@ class TakeoverService:
         if not candidates:
             return []
 
-        handled_ids = set(current_source_ids)
+        current_ids = set(current_source_ids)
+        if references_image:
+            return [
+                image
+                for image in reversed(candidates)
+                if image.boxim_message_id not in current_ids
+            ]
+
+        handled_ids = set(current_ids)
         task_sources = (
             db.query(TakeoverReplyTask.source_message_ids)
             .filter(