feat: enhance request payload handling for AI messages with tool calls

--bug=1068446@tapd-62980211 --user=刘瑞斌 【应用】AI对话开启思考过程并引用智能体作为技能，对话调用技能后，返回报错 https://www.tapd.cn/62980211/s/1902267

Author: liuruibin

apps/models_provider/impl/aliyun_bai_lian_model_provider/model/llm.py

@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
-from typing import Dict
+from typing import Dict, Any
+
+from langchain_core.language_models import LanguageModelInput
+from langchain_core.messages import AIMessage
 
 from models_provider.base_model_provider import MaxKBBaseModel
 from models_provider.impl.base_chat_open_ai import BaseChatOpenAI
@@ -23,3 +26,38 @@ def new_instance(model_type, model_name, model_credential: Dict[str, object], **
             streaming=True,
             **optional_params,
         )
+
+    def _get_request_payload(
+            self,
+            input_: LanguageModelInput,
+            *,
+            stop: list[str] | None = None,
+            **kwargs: Any,
+    ) -> dict:
+        # Collect reasoning_content from AIMessages with tool_calls before base conversion.
+        # When enable_thinking=true, Bailian API requires reasoning_content on any assistant
+        # message that contains tool_calls (defaults to "" when not present).
+        messages = self._convert_input(input_).to_messages()
+        reasoning_content_map = {}
+        for i, msg in enumerate(messages):
+            if (
+                    isinstance(msg, AIMessage)
+                    and (msg.tool_calls or msg.invalid_tool_calls)
+            ):
+                reasoning_content_map[i] = msg.additional_kwargs.get(
+                    "reasoning_content") or ""
+
+        payload = super()._get_request_payload(input_, stop=stop, **kwargs)
+
+        # Inject reasoning_content into assistant messages with tool_calls so that
+        # Bailian deepseek thinking mode does not reject the request with a 400 error.
+        if "messages" in payload and reasoning_content_map:
+            for i, message in enumerate(payload["messages"]):
+                if (
+                        i in reasoning_content_map
+                        and message.get("role") == "assistant"
+                        and message.get("tool_calls")
+                ):
+                    message["reasoning_content"] = reasoning_content_map[i]
+
+        return payload