Tolerate malformed stringified writer rewrites

src/vk_parser_app/workers/ai_writer.py

@@ -107,10 +107,44 @@ def decode_jsonish(value: Any) -> Any:
         try:
             value = json.loads(raw)
         except json.JSONDecodeError:
+            salvaged = loads_json_prefix(raw)
+            if salvaged is not None:
+                value = salvaged
+                continue
             return value
     return value
 
 
+def loads_json_prefix(raw: str) -> Any | None:
+    if not raw or raw[0] not in "[{":
+        return None
+    pairs = {"[": "]", "{": "}"}
+    stack: list[str] = []
+    in_string = False
+    escaped = False
+    for idx, char in enumerate(raw):
+        if in_string:
+            if escaped:
+                escaped = False
+            elif char == "\\":
+                escaped = True
+            elif char == '"':
+                in_string = False
+            continue
+        if char == '"':
+            in_string = True
+        elif char in pairs:
+            stack.append(pairs[char])
+        elif stack and char == stack[-1]:
+            stack.pop()
+            if not stack:
+                try:
+                    return json.loads(raw[: idx + 1])
+                except json.JSONDecodeError:
+                    return None
+    return None
+
+
 def response_usage(response: Any) -> dict[str, Any]:
     usage = getattr(response, "usage", None)
     if usage is None and isinstance(response, dict):