chore: use a Conversation type (#3735)

crates/goose/src/agents/subagent.rs

@@ -3,7 +3,6 @@ use crate::{
     agents::extension::ExtensionConfig,
     agents::{extension_manager::ExtensionManager, Agent, TaskConfig},
     config::ExtensionConfigManager,
-    message::{Message, MessageContent, ToolRequest},
     prompt_template::render_global_file,
     providers::errors::ProviderError,
 };
@@ -13,6 +12,8 @@ use mcp_core::handler::ToolError;
 use rmcp::model::Tool;
 use serde::{Deserialize, Serialize};
 // use serde_json::{self};
+use crate::conversation::message::{Message, MessageContent, ToolRequest};
+use crate::conversation::Conversation;
 use std::{collections::HashMap, sync::Arc};
 use tokio::sync::{Mutex, RwLock};
 use tokio_util::sync::CancellationToken;
@@ -41,7 +42,7 @@ pub struct SubAgentProgress {
 /// A specialized agent that can handle specific tasks independently
 pub struct SubAgent {
     pub id: String,
-    pub conversation: Arc<Mutex<Vec<Message>>>,
+    pub conversation: Arc<Mutex<Conversation>>,
     pub status: Arc<RwLock<SubAgentStatus>>,
     pub config: TaskConfig,
     pub turn_count: Arc<Mutex<usize>>,
@@ -80,7 +81,7 @@ impl SubAgent {
 
         let subagent = Arc::new(SubAgent {
             id: task_config.id.clone(),
-            conversation: Arc::new(Mutex::new(Vec::new())),
+            conversation: Arc::new(Mutex::new(Conversation::new_unvalidated(Vec::new()))),
             status: Arc::new(RwLock::new(SubAgentStatus::Ready)),
             config: task_config,
             turn_count: Arc::new(Mutex::new(0)),
@@ -107,7 +108,7 @@ impl SubAgent {
         &self,
         message: String,
         task_config: TaskConfig,
-    ) -> Result<Vec<Message>, anyhow::Error> {
+    ) -> Result<Conversation, anyhow::Error> {
         debug!("Processing message for subagent {}", self.id);
 
         // Get provider from task config
@@ -128,7 +129,10 @@ impl SubAgent {
         }
 
         // Get the current conversation for context
-        let mut messages = self.get_conversation().await;
+        let mut messages = {
+            let conversation = self.conversation.lock().await;
+            conversation.clone()
+        };
 
         // Get tools from the subagent's own extension manager
         let tools: Vec<Tool> = self
@@ -156,7 +160,7 @@ impl SubAgent {
             match Agent::generate_response_from_provider(
                 Arc::clone(provider),
                 &system_prompt,
-                &messages,
+                messages.messages(),
                 &tools,
                 &toolshim_tools,
             )
@@ -264,11 +268,6 @@ impl SubAgent {
         conversation.push(message);
     }
 
-    /// Get the full conversation history
-    async fn get_conversation(&self) -> Vec<Message> {
-        self.conversation.lock().await.clone()
-    }
-
     /// Build the system prompt for the subagent using the template
     async fn build_system_prompt(&self, available_tools: &[Tool]) -> Result<String, anyhow::Error> {
         let mut context = HashMap::new();