chore: Enhance a2a part converters

a. fix binary data conversion
b. support thoughts, code execution result, executable codes conversion

PiperOrigin-RevId: 775827259

src/google/adk/a2a/converters/part_converter.py

@@ -18,6 +18,7 @@ module containing utilities for conversion betwen A2A Part and Google GenAI Part
 
 from __future__ import annotations
 
+import base64
 import json
 import logging
 import sys
@@ -43,8 +44,11 @@ from ...utils.feature_decorator import working_in_progress
 logger = logging.getLogger('google_adk.' + __name__)
 
 A2A_DATA_PART_METADATA_TYPE_KEY = 'type'
+A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY = 'is_long_running'
 A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL = 'function_call'
 A2A_DATA_PART_METADATA_TYPE_FUNCTION_RESPONSE = 'function_response'
+A2A_DATA_PART_METADATA_TYPE_CODE_EXECUTION_RESULT = 'code_execution_result'
+A2A_DATA_PART_METADATA_TYPE_EXECUTABLE_CODE = 'executable_code'
 
 
 @working_in_progress
@@ -67,7 +71,8 @@ def convert_a2a_part_to_genai_part(
     elif isinstance(part.file, a2a_types.FileWithBytes):
       return genai_types.Part(
           inline_data=genai_types.Blob(
-              data=part.file.bytes.encode('utf-8'), mime_type=part.file.mimeType
+              data=base64.b64decode(part.file.bytes),
+              mime_type=part.file.mimeType,
           )
       )
     else:
@@ -84,7 +89,11 @@ def convert_a2a_part_to_genai_part(
     # response.
     # TODO once A2A defined how to suervice such information, migrate below
     # logic accordinlgy
-    if part.metadata and A2A_DATA_PART_METADATA_TYPE_KEY in part.metadata:
+    if (
+        part.metadata
+        and _get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)
+        in part.metadata
+    ):
       if (
           part.metadata[_get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)]
           == A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
@@ -103,6 +112,24 @@ def convert_a2a_part_to_genai_part(
                 part.data, by_alias=True
             )
         )
+      if (
+          part.metadata[_get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)]
+          == A2A_DATA_PART_METADATA_TYPE_CODE_EXECUTION_RESULT
+      ):
+        return genai_types.Part(
+            code_execution_result=genai_types.CodeExecutionResult.model_validate(
+                part.data, by_alias=True
+            )
+        )
+      if (
+          part.metadata[_get_adk_metadata_key(A2A_DATA_PART_METADATA_TYPE_KEY)]
+          == A2A_DATA_PART_METADATA_TYPE_EXECUTABLE_CODE
+      ):
+        return genai_types.Part(
+            executable_code=genai_types.ExecutableCode.model_validate(
+                part.data, by_alias=True
+            )
+        )
     return genai_types.Part(text=json.dumps(part.data))
 
   logger.warning(
@@ -118,27 +145,40 @@ def convert_genai_part_to_a2a_part(
     part: genai_types.Part,
 ) -> Optional[a2a_types.Part]:
   """Convert a Google GenAI Part to an A2A Part."""
+
   if part.text:
-    return a2a_types.TextPart(text=part.text)
+    a2a_part = a2a_types.TextPart(text=part.text)
+    if part.thought is not None:
+      a2a_part.metadata = {_get_adk_metadata_key('thought'): part.thought}
+    return a2a_types.Part(root=a2a_part)
 
   if part.file_data:
-    return a2a_types.FilePart(
-        file=a2a_types.FileWithUri(
-            uri=part.file_data.file_uri,
-            mimeType=part.file_data.mime_type,
+    return a2a_types.Part(
+        root=a2a_types.FilePart(
+            file=a2a_types.FileWithUri(
+                uri=part.file_data.file_uri,
+                mimeType=part.file_data.mime_type,
+            )
         )
     )
 
   if part.inline_data:
-    return a2a_types.Part(
-        root=a2a_types.FilePart(
-            file=a2a_types.FileWithBytes(
-                bytes=part.inline_data.data,
-                mimeType=part.inline_data.mime_type,
-            )
+    a2a_part = a2a_types.FilePart(
+        file=a2a_types.FileWithBytes(
+            bytes=base64.b64encode(part.inline_data.data).decode('utf-8'),
+            mimeType=part.inline_data.mime_type,
         )
     )
 
+    if part.video_metadata:
+      a2a_part.metadata = {
+          _get_adk_metadata_key(
+              'video_metadata'
+          ): part.video_metadata.model_dump(by_alias=True, exclude_none=True)
+      }
+
+    return a2a_types.Part(root=a2a_part)
+
   # Conver the funcall and function reponse to A2A DataPart.
   # This is mainly for converting human in the loop and auth request and
   # response.
@@ -151,9 +191,9 @@ def convert_genai_part_to_a2a_part(
                 by_alias=True, exclude_none=True
             ),
             metadata={
-                A2A_DATA_PART_METADATA_TYPE_KEY: (
-                    A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
-                )
+                _get_adk_metadata_key(
+                    A2A_DATA_PART_METADATA_TYPE_KEY
+                ): A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL
             },
         )
     )
@@ -165,9 +205,37 @@ def convert_genai_part_to_a2a_part(
                 by_alias=True, exclude_none=True
             ),
             metadata={
-                A2A_DATA_PART_METADATA_TYPE_KEY: (
-                    A2A_DATA_PART_METADATA_TYPE_FUNCTION_RESPONSE
-                )
+                _get_adk_metadata_key(
+                    A2A_DATA_PART_METADATA_TYPE_KEY
+                ): A2A_DATA_PART_METADATA_TYPE_FUNCTION_RESPONSE
+            },
+        )
+    )
+
+  if part.code_execution_result:
+    return a2a_types.Part(
+        root=a2a_types.DataPart(
+            data=part.code_execution_result.model_dump(
+                by_alias=True, exclude_none=True
+            ),
+            metadata={
+                _get_adk_metadata_key(
+                    A2A_DATA_PART_METADATA_TYPE_KEY
+                ): A2A_DATA_PART_METADATA_TYPE_CODE_EXECUTION_RESULT
+            },
+        )
+    )
+
+  if part.executable_code:
+    return a2a_types.Part(
+        root=a2a_types.DataPart(
+            data=part.executable_code.model_dump(
+                by_alias=True, exclude_none=True
+            ),
+            metadata={
+                _get_adk_metadata_key(
+                    A2A_DATA_PART_METADATA_TYPE_KEY
+                ): A2A_DATA_PART_METADATA_TYPE_EXECUTABLE_CODE
             },
         )
     )