Feat/workflow phase2 (#4687)

api/core/tools/tool_engine.py

@@ -1,7 +1,10 @@
 from copy import deepcopy
 from datetime import datetime, timezone
+from mimetypes import guess_type
 from typing import Union
 
+from yarl import URL
+
 from core.app.entities.app_invoke_entities import InvokeFrom
 from core.callback_handler.agent_tool_callback_handler import DifyAgentCallbackHandler
 from core.callback_handler.workflow_tool_callback_handler import DifyWorkflowCallbackHandler
@@ -17,6 +20,7 @@ from core.tools.errors import (
     ToolProviderNotFoundError,
 )
 from core.tools.tool.tool import Tool
+from core.tools.tool.workflow_tool import WorkflowTool
 from core.tools.utils.message_transformer import ToolFileMessageTransformer
 from extensions.ext_database import db
 from models.model import Message, MessageFile
@@ -115,7 +119,8 @@ class ToolEngine:
     @staticmethod
     def workflow_invoke(tool: Tool, tool_parameters: dict,
                         user_id: str, workflow_id: str, 
-                        workflow_tool_callback: DifyWorkflowCallbackHandler) \
+                        workflow_tool_callback: DifyWorkflowCallbackHandler,
+                        workflow_call_depth: int) \
                               -> list[ToolInvokeMessage]:
         """
         Workflow invokes the tool with the given arguments.
@@ -127,6 +132,9 @@ class ToolEngine:
                 tool_inputs=tool_parameters
             )
 
+            if isinstance(tool, WorkflowTool):
+                tool.workflow_call_depth = workflow_call_depth + 1
+
             response = tool.invoke(user_id, tool_parameters)
 
             # hit the callback handler
@@ -195,8 +203,24 @@ class ToolEngine:
         for response in tool_response:
             if response.type == ToolInvokeMessage.MessageType.IMAGE_LINK or \
                 response.type == ToolInvokeMessage.MessageType.IMAGE:
+                mimetype = None
+                if response.meta.get('mime_type'):
+                    mimetype = response.meta.get('mime_type')
+                else:
+                    try:
+                        url = URL(response.message)
+                        extension = url.suffix
+                        guess_type_result, _ = guess_type(f'a{extension}')
+                        if guess_type_result:
+                            mimetype = guess_type_result
+                    except Exception:
+                        pass
+                
+                if not mimetype:
+                    mimetype = 'image/jpeg'
+                    
                 result.append(ToolInvokeMessageBinary(
-                    mimetype=response.meta.get('mime_type', 'octet/stream'),
+                    mimetype=response.meta.get('mime_type', 'image/jpeg'),
                     url=response.message,
                     save_as=response.save_as,
                 ))