(fix) CodeActAgent: fix issues with vision support in prompts (#3665)

* CodeActAgent: fix message prep if prompt caching is not supported

* fix python version in regen tests workflow

* fix in conftest "mock_completion" method

* add disable_vision to LLMConfig; revert change in message parsing in llm.py

* format messages in several files for completion

* refactored message(s) formatting (llm.py); added vision_is_active()

* fix a unit test

* regenerate: added LOG_TO_FILE and FORCE_REGENERATE env flags

* try to fix path to logs folder in workflow

* llm: prevent index error

* try FORCE_USE_LLM in regenerate

* tweaks everywhere...

* fix 2 random unit test errors :(

* added FORCE_REGENERATE_TESTS=true to regenerate CLI

* fix test_lint_file_fail_typescript again

* double-quotes for env vars in workflow; llm logger set to debug

* fix typo in regenerate

* regenerate iterations now 20; applied iteration counter fix by Li

* regenerate: pass FORCE_REGENERATE flag into env

* fixes for int tests. several mock files updated.

* browsing_agent: fix response_parser.py adding ) to empty response

* test_browse_internet: fix skipif and revert obsolete mock files

* regenerate: fi bracketing for http server start/kill conditions

* disable test_browse_internet for CodeAct*Agents; mock files updated after merge

* missed to include more mock files earlier

* reverts after review feedback from Li

* forgot one

* browsing agent test, partial fixes and updated mock files

* test_browse_internet works in my WSL now!

* adapt unit test test_prompt_caching.py

* add DEBUG to regenerate workflow command

* convert regenerate workflow params to inputs

* more integration test mock files updated

* more files

* test_prompt_caching: restored test_prompt_caching_headers purpose

* file_ops: fix potential exception, like "cross device copy"; fixed mock files accordingly

* reverts/changes wrt feedback from xingyao

* updated docs and config template

* code cleanup wrt review feedback

openhands/core/message.py

@@ -1,8 +1,11 @@
 from enum import Enum
+from typing import Union
 
 from pydantic import BaseModel, Field, model_serializer
 from typing_extensions import Literal
 
+from openhands.core.logger import openhands_logger as logger
+
 
 class ContentType(Enum):
     TEXT = 'text'
@@ -10,7 +13,7 @@ class ContentType(Enum):
 
 
 class Content(BaseModel):
-    type: ContentType
+    type: str
     cache_prompt: bool = False
 
     @model_serializer
@@ -19,13 +22,13 @@ class Content(BaseModel):
 
 
 class TextContent(Content):
-    type: ContentType = ContentType.TEXT
+    type: str = ContentType.TEXT.value
     text: str
 
     @model_serializer
     def serialize_model(self):
         data: dict[str, str | dict[str, str]] = {
-            'type': self.type.value,
+            'type': self.type,
             'text': self.text,
         }
         if self.cache_prompt:
@@ -34,14 +37,14 @@ class TextContent(Content):
 
 
 class ImageContent(Content):
-    type: ContentType = ContentType.IMAGE_URL
+    type: str = ContentType.IMAGE_URL.value
     image_urls: list[str]
 
     @model_serializer
     def serialize_model(self):
         images: list[dict[str, str | dict[str, str]]] = []
         for url in self.image_urls:
-            images.append({'type': self.type.value, 'image_url': {'url': url}})
+            images.append({'type': self.type, 'image_url': {'url': url}})
         if self.cache_prompt and images:
             images[-1]['cache_control'] = {'type': 'ephemeral'}
         return images
@@ -65,4 +68,50 @@ class Message(BaseModel):
             elif isinstance(item, ImageContent):
                 content.extend(item.model_dump())
 
-        return {'role': self.role, 'content': content}
+        return {'content': content, 'role': self.role}
+
+
+def format_messages(
+    messages: Union[Message, list[Message]], with_images: bool
+) -> list[dict]:
+    if not isinstance(messages, list):
+        messages = [messages]
+
+    if with_images:
+        return [message.model_dump() for message in messages]
+
+    converted_messages = []
+    for message in messages:
+        content_str = ''
+        role = 'user'
+        if 'role' in message:
+            role = message['role']
+        if isinstance(message, str):
+            content_str = content_str + message + '\n'
+            continue
+
+        if isinstance(message, dict):
+            if 'content' in message:
+                content_str = content_str + message['content'] + '\n'
+        elif isinstance(message, Message):
+            role = message.role
+            for content in message.content:
+                if isinstance(content, list):
+                    for item in content:
+                        if isinstance(item, TextContent):
+                            content_str = content_str + item.text + '\n'
+                elif isinstance(content, TextContent):
+                    content_str = content_str + content.text + '\n'
+        else:
+            logger.error(
+                f'>>> `message` is not a string, dict, or Message: {type(message)}'
+            )
+
+        if content_str:
+            converted_messages.append(
+                {
+                    'role': role,
+                    'content': content_str,
+                }
+            )
+    return converted_messages