Refactor implementation of strands agents migration.

- Split `chat()` into common and framework specific implementation.
  1. (Common preprocess) Setup messages and LLM parameters.
  2. (Framework specific) Converse with LLM and build response messages.
  3. (Common postprocess) Update conversation and store into database.

- Consolidate the code for converting between application-defined models (messages, contents and tools) and Strands models into `converters` module.

- Fix some bugs in streaming processing
  - Fail to continue generation based on a message with `ReasoningContent`.
  - Not handling `redactedContent` correctly.

Author: Yukinobu-Mine

backend/app/agents/utils.py

@@ -1,14 +1,16 @@
 import logging
 from typing import Dict
+from typing_extensions import deprecated
 
 from app.agents.tools.agent_tool import AgentTool
 from app.agents.tools.bedrock_agent import BedrockAgent, bedrock_agent_tool
 from app.agents.tools.calculator import calculator_tool
 from app.agents.tools.internet_search import internet_search_tool
 from app.agents.tools.knowledge import create_knowledge_tool
 from app.agents.tools.simple_list import simple_list_tool
+from app.bedrock import is_tooluse_supported
 from app.repositories.models.custom_bot import BotModel
-from typing_extensions import deprecated
+from app.routes.schemas.conversation import type_model_name
 
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.INFO)
@@ -23,7 +25,9 @@ def get_available_tools() -> list[AgentTool]:
 
 
 @deprecated("Use get_strands_tools() instead")
-def get_tools(bot: BotModel | None) -> Dict[str, AgentTool]:
+def get_tools(
+    bot: BotModel | None, model_name: type_model_name
+) -> Dict[str, AgentTool]:
     """Get a dictionary of tools based on bot's tool configuration
 
     Args:
@@ -34,6 +38,12 @@ def get_tools(bot: BotModel | None) -> Dict[str, AgentTool]:
     """
     tools: Dict[str, AgentTool] = {}
 
+    if not is_tooluse_supported(model_name):
+        logger.warning(
+            f"Tool use is not supported for model {model_name}. Returning empty tool list."
+        )
+        return tools
+
     # Return empty dictionary if bot is None or agent is not enabled
     if not bot or not bot.is_agent_enabled():
         return tools