feat(rag): Support RAG SDK (#1322)

dbgpt/core/awel/dag/base.py

@@ -710,6 +710,11 @@ class DAG:
         self.print_tree()
         return _visualize_dag(self, view=view, **kwargs)
 
+    def show(self, mermaid: bool = False) -> Any:
+        """Return the graph of current DAG."""
+        dot, mermaid_str = _get_graph(self)
+        return mermaid_str if mermaid else dot
+
     def __enter__(self):
         """Enter a DAG context."""
         DAGVar.enter_dag(self)
@@ -813,26 +818,12 @@ def _handle_dag_nodes(
         _handle_dag_nodes(is_down_to_up, level, node, func)
 
 
-def _visualize_dag(
-    dag: DAG, view: bool = True, generate_mermaid: bool = True, **kwargs
-) -> Optional[str]:
-    """Visualize the DAG.
-
-    Args:
-        dag (DAG): The DAG to visualize
-        view (bool, optional): Whether view the DAG graph. Defaults to True.
-        generate_mermaid (bool, optional): Whether to generate a Mermaid syntax file.
-            Defaults to True.
-
-    Returns:
-        Optional[str]: The filename of the DAG graph
-    """
+def _get_graph(dag: DAG):
     try:
         from graphviz import Digraph
     except ImportError:
         logger.warn("Can't import graphviz, skip visualize DAG")
-        return None
-
+        return None, None
     dot = Digraph(name=dag.dag_id)
     mermaid_str = "graph TD;\n"  # Initialize Mermaid graph definition
     # Record the added edges to avoid adding duplicate edges
@@ -851,6 +842,26 @@ def _visualize_dag(
 
     for root in dag.root_nodes:
         add_edges(root)
+    return dot, mermaid_str
+
+
+def _visualize_dag(
+    dag: DAG, view: bool = True, generate_mermaid: bool = True, **kwargs
+) -> Optional[str]:
+    """Visualize the DAG.
+
+    Args:
+        dag (DAG): The DAG to visualize
+        view (bool, optional): Whether view the DAG graph. Defaults to True.
+        generate_mermaid (bool, optional): Whether to generate a Mermaid syntax file.
+            Defaults to True.
+
+    Returns:
+        Optional[str]: The filename of the DAG graph
+    """
+    dot, mermaid_str = _get_graph(dag)
+    if not dot:
+        return None
     filename = f"dag-vis-{dag.dag_id}.gv"
     if "filename" in kwargs:
         filename = kwargs["filename"]