refactor(openai,grouping): system/user separation for planning

- Updated openai.rs to change structured_output_blocking signature: now accepts a system message and a separate set of chat messages for more flexible composition when calling OpenAI. Updated message preparation logic accordingly.
- groupings.rs updated to use ChatMessage and the new API from openai.rs, switching message construction to the new approach. Updates grouping logic to call structured_output_blocking with system and user separation.

Together these changes improve the modularity and adaptability of agent planning workflows and allow easier integration of new agent modules.

Author: estib-vega

crates/but-action/src/grouping.rs

@@ -1,11 +1,10 @@
 use std::{fmt::Debug, str};
 
-use async_openai::types::{ChatCompletionRequestSystemMessage, ChatCompletionRequestUserMessage};
 use but_tools::workspace::ProjectStatus;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
-use crate::{OpenAiProvider, openai};
+use crate::{ChatMessage, OpenAiProvider, openai};
 
 #[derive(Debug, Serialize, Deserialize, JsonSchema)]
 pub enum BranchSuggestion {
@@ -97,13 +96,11 @@ pub fn group(openai: &OpenAiProvider, project_status: &ProjectStatus) -> anyhow:
         serialized_project_status
     );
 
-    let messages = vec![
-        ChatCompletionRequestSystemMessage::from(system_message).into(),
-        ChatCompletionRequestUserMessage::from(user_message).into(),
-    ];
+    let messages = vec![ChatMessage::User(user_message)];
 
-    let grouping = openai::structured_output_blocking::<Grouping>(openai, messages)?
-        .ok_or_else(|| anyhow::anyhow!("Failed to get grouping from OpenAI"))?;
+    let grouping =
+        openai::structured_output_blocking::<Grouping>(openai, system_message, messages)?
+            .ok_or_else(|| anyhow::anyhow!("Failed to get grouping from OpenAI"))?;
 
     Ok(grouping)
 }

crates/but-action/src/openai.rs

@@ -121,15 +121,24 @@ pub fn structured_output_blocking<
     T: serde::Serialize + DeserializeOwned + JsonSchema + std::marker::Send + 'static,
 >(
     openai: &OpenAiProvider,
-    messages: Vec<ChatCompletionRequestMessage>,
+    system_message: &str,
+    chat_messages: Vec<ChatMessage>,
 ) -> anyhow::Result<Option<T>> {
     let client = openai.client()?;
-    let messages_owned = messages.clone();
+    let mut messages: Vec<ChatCompletionRequestMessage> =
+        vec![ChatCompletionRequestSystemMessage::from(system_message).into()];
+
+    messages.extend(
+        chat_messages
+            .into_iter()
+            .map(ChatCompletionRequestMessage::from)
+            .collect::<Vec<_>>(),
+    );
 
     std::thread::spawn(move || {
         tokio::runtime::Runtime::new()
             .unwrap()
-            .block_on(structured_output::<T>(&client, messages_owned))
+            .block_on(structured_output::<T>(&client, messages))
     })
     .join()
     .unwrap()