feat: enhance mermaid graph rendering with unique node IDs and subgra…

…ph support

chore: add tests for most functionality in web_interface.py

src/planai/web_interface.py

@@ -184,21 +184,77 @@ def render_mermaid_graph(graph: "Graph"):
     # Start with graph definition
     mermaid = """graph TD\n"""
 
+    # Track unique IDs for nodes and subgraphs
+    unique_id = 0
+    mapping = {}
+    subgraph_workers = []
+
+    # Helper function to get or create unique ID for a worker
+    def get_worker_id(worker):
+        nonlocal unique_id
+        if worker not in mapping:
+            unique_id += 1
+            mapping[worker] = f"task_{unique_id}"
+        return mapping[worker]
+
+    # Helper function to create node definition
+    def create_node(worker):
+        worker_id = get_worker_id(worker)
+        return f"{worker_id}[{worker.name.replace(' ', '_')}]"
+
+    def is_subgraph(worker):
+        if not hasattr(worker, "graph"):
+            return False
+        if not isinstance(worker.graph, object):
+            return False
+        return hasattr(worker.graph, "dependencies")
+
+    # First pass: identify subgraphs and create all node mappings
+    for upstream, downstream_list in graph.dependencies.items():
+        get_worker_id(upstream)
+        for downstream in downstream_list:
+            get_worker_id(downstream)
+            # Check if either worker is a SubGraphWorker
+            if is_subgraph(upstream):
+                if upstream not in subgraph_workers:
+                    subgraph_workers.append(upstream)
+            if is_subgraph(downstream):
+                if downstream not in subgraph_workers:
+                    subgraph_workers.append(downstream)
+
+    # Add subgraphs first
+    for worker in subgraph_workers:
+        subgraph_id = get_worker_id(worker)
+        mermaid += f"    subgraph {subgraph_id}[{worker.name}]\n"
+
+        # Add nodes and edges within the subgraph
+        for sub_upstream, sub_downstream_list in worker.graph.dependencies.items():
+            sub_upstream_id = get_worker_id(sub_upstream)
+            mermaid += f"        {create_node(sub_upstream)}\n"
+            for sub_downstream in sub_downstream_list:
+                sub_downstream_id = get_worker_id(sub_downstream)
+                mermaid += f"        {create_node(sub_downstream)}\n"
+                mermaid += f"        {sub_upstream_id}-->{sub_downstream_id}\n"
+
+        mermaid += "    end\n"
+
     # Add all edges from dependencies
     for upstream, downstream_list in graph.dependencies.items():
+        upstream_id = get_worker_id(upstream)
         for downstream in downstream_list:
-            # Create an edge for each dependency using worker names
-            # Sanitize names by replacing spaces with underscores
-            src = upstream.name.replace(" ", "_")
-            dst = downstream.name.replace(" ", "_")
-            mermaid += f"    {src}-->{dst}\n"
+            downstream_id = get_worker_id(downstream)
+            mermaid += f"    {upstream_id}[{upstream.name}]-->{downstream_id}[{downstream.name}]\n"
 
     return mermaid
 
 
-def run_web_interface(disp: "Dispatcher", port=5000):
+def set_dispatcher(disp: "Dispatcher"):
     global dispatcher
     dispatcher = disp
+
+
+def run_web_interface(disp: "Dispatcher", port=5000):
+    set_dispatcher(disp)
     app.run(debug=False, use_reloader=False, port=port)