feat(backend): tool support in send agent prompt, regularize inference messages (wip)

backend/src/utils.py

@@ -1,14 +1,36 @@
 import json
 
 from stream import Stream
-from tool import ToolSpec
+from tool import ToolSpec, ToolCall
+from inference import Message
+
+# TODO: Move to module 'format'
+def encode_value(value):
+    if isinstance(value, ToolSpec):
+        return value.to_openai_dict()
+    elif isinstance(value, Message):
+        return {'type': value.type, 'content': encode_value(value.content)}
+    elif isinstance(value, ToolCall):
+        json = {
+            'id': value.id,
+            'tool_name': value.tool_name,
+            'arguments': encode_value(value.arguments),
+        }
+        if value.result != None:
+            json['result'] = encode_value(value.result),
+        return json
+    elif isinstance(value, Stream):
+        return {'streamId': value.id}
+    else:
+        return value
 
 def encode_json(value):
     def encode_unknown(value):
-        if isinstance(value, ToolSpec):
-            return value.to_openai_dict()
-        elif isinstance(value, Stream):
-            return {'streamId': value.id}
+        # All complex values are transformed to a dict
+        value = encode_value(value)
+        # otherwise simply show the repr
+        if isinstance(value, dict):
+            return value
         else:
             return repr(value)
     return json.dumps(value, default=encode_unknown)