feat(core): AWEL flow 2.0 backend code (#1879)

Co-authored-by: yhjun1026 <460342015@qq.com>

dbgpt/serve/flow/service/service.py

@@ -9,7 +9,6 @@ from dbgpt._private.pydantic import model_to_json
 from dbgpt.agent import AgentDummyTrigger
 from dbgpt.component import SystemApp
 from dbgpt.core.awel import DAG, BaseOperator, CommonLLMHttpRequestBody
-from dbgpt.core.awel.dag.dag_manager import DAGManager
 from dbgpt.core.awel.flow.flow_factory import (
     FlowCategory,
     FlowFactory,
@@ -34,7 +33,7 @@ from dbgpt.storage.metadata._base_dao import QUERY_SPEC
 from dbgpt.util.dbgpts.loader import DBGPTsLoader
 from dbgpt.util.pagination_utils import PaginationResult
 
-from ..api.schemas import ServeRequest, ServerResponse
+from ..api.schemas import FlowDebugRequest, ServeRequest, ServerResponse
 from ..config import SERVE_CONFIG_KEY_PREFIX, SERVE_SERVICE_COMPONENT_NAME, ServeConfig
 from ..models.models import ServeDao, ServeEntity
 
@@ -147,7 +146,9 @@ class Service(BaseService[ServeEntity, ServeRequest, ServerResponse]):
                 raise ValueError(
                     f"Create DAG {request.name} error, define_type: {request.define_type}, error: {str(e)}"
                 ) from e
-        res = self.dao.create(request)
+        self.dao.create(request)
+        # Query from database
+        res = self.get({"uid": request.uid})
 
         state = request.state
         try:
@@ -574,3 +575,61 @@ class Service(BaseService[ServeEntity, ServeRequest, ServerResponse]):
                 return FlowCategory.CHAT_FLOW
         except Exception:
             return FlowCategory.COMMON
+
+    async def debug_flow(
+        self, request: FlowDebugRequest, default_incremental: Optional[bool] = None
+    ) -> AsyncIterator[ModelOutput]:
+        """Debug the flow.
+
+        Args:
+            request (FlowDebugRequest): The request
+            default_incremental (Optional[bool]): The default incremental configuration
+
+        Returns:
+            AsyncIterator[ModelOutput]: The output
+        """
+        from dbgpt.core.awel.dag.dag_manager import DAGMetadata, _parse_metadata
+
+        dag = self._flow_factory.build(request.flow)
+        leaf_nodes = dag.leaf_nodes
+        if len(leaf_nodes) != 1:
+            raise ValueError("Chat Flow just support one leaf node in dag")
+        task = cast(BaseOperator, leaf_nodes[0])
+        dag_metadata = _parse_metadata(dag)
+        # TODO: Run task with variables
+        variables = request.variables
+        dag_request = request.request
+
+        if isinstance(request.request, CommonLLMHttpRequestBody):
+            incremental = request.request.incremental
+        elif isinstance(request.request, dict):
+            incremental = request.request.get("incremental", False)
+        else:
+            raise ValueError("Invalid request type")
+
+        if default_incremental is not None:
+            incremental = default_incremental
+
+        try:
+            async for output in safe_chat_stream_with_dag_task(
+                task, dag_request, incremental
+            ):
+                yield output
+        except HTTPException as e:
+            yield ModelOutput(error_code=1, text=e.detail, incremental=incremental)
+        except Exception as e:
+            yield ModelOutput(error_code=1, text=str(e), incremental=incremental)
+
+    async def _wrapper_chat_stream_flow_str(
+        self, stream_iter: AsyncIterator[ModelOutput]
+    ) -> AsyncIterator[str]:
+
+        async for output in stream_iter:
+            text = output.text
+            if text:
+                text = text.replace("\n", "\\n")
+            if output.error_code != 0:
+                yield f"data:[SERVER_ERROR]{text}\n\n"
+                break
+            else:
+                yield f"data:{text}\n\n"