feat(llm): add message parsing for OpenAI client

Added parse_messages method to handle structured prompt input for OpenAI API. The method converts human/bot/compact prefixes to appropriate OpenAI roles (user/assistant/system) and properly formats multi-line messages. This enables more complex conversation structures in prompts while maintaining compatibility with the OpenAI API format.

Removed the direct prompt-to-message conversion in generate and generate_stream methods, replacing it with the new parse_messages utility. Also reorganized the impl blocks for better code organization.

src/llm/mod.rs

@@ -34,15 +34,6 @@ pub struct OpenAIClient {
     api_key: String,
     base_url: String,
 }
-impl OpenAIClient {
-    pub fn new(api_key: String, base_url: Option<String>) -> Self {
-        Self {
-            client: reqwest::Client::new(),
-            api_key,
-            base_url: base_url.unwrap()
-        }
-    }
-}
 #[async_trait]
 impl LLMProvider for OpenAIClient {
     async fn generate(
@@ -50,13 +41,15 @@ impl LLMProvider for OpenAIClient {
         prompt: &str,
         _config: &Value,
     ) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
+        let messages = self.parse_messages(prompt);
+
         let response = self
             .client
             .post(&format!("{}/v1/chat/completions/", self.base_url))
             .header("Authorization", format!("Bearer {}", self.api_key))
             .json(&serde_json::json!({
                 "model": "gpt-3.5-turbo",
-                "messages": [{"role": "user", "content": prompt}],
+                "messages": messages,
                 "max_tokens": 1000
             }))
             .send()
@@ -79,13 +72,15 @@ impl LLMProvider for OpenAIClient {
         _config: &Value,
         tx: mpsc::Sender<String>,
     ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+        let messages = self.parse_messages(prompt);
+
         let response = self
             .client
             .post(&format!("{}/v1/chat/completions", self.base_url))
             .header("Authorization", format!("Bearer {}", self.api_key))
             .json(&serde_json::json!({
                 "model": "gpt-3.5-turbo",
-                "messages": [{"role": "user", "content": prompt}],
+                "messages": messages,
                 "max_tokens": 1000,
                 "stream": true
             }))
@@ -116,3 +111,56 @@ impl LLMProvider for OpenAIClient {
         Ok(())
     }
 }
+
+impl OpenAIClient {
+    pub fn new(api_key: String, base_url: Option<String>) -> Self {
+        Self {
+            client: reqwest::Client::new(),
+            api_key,
+            base_url: base_url.unwrap()
+        }
+    }
+
+    fn parse_messages(&self, prompt: &str) -> Vec<Value> {
+        let mut messages = Vec::new();
+        let mut current_role = None;
+        let mut current_content = String::new();
+
+        for line in prompt.lines() {
+            if let Some(role_end) = line.find(':') {
+                let role_part = &line[..role_end].trim().to_lowercase();
+                let role = match role_part.as_str() {
+                    "human" => "user",
+                    "bot" => "assistant", 
+                    "compact" => "system",
+                    _ => continue
+                };
+                {
+                    if let Some(r) = current_role.take() {
+                        messages.push(serde_json::json!({
+                            "role": r,
+                            "content": current_content.trim()
+                        }));
+                    }
+                    current_role = Some(role);
+                    current_content = line[role_end + 1..].trim_start().to_string();
+                    continue;
+                }
+            }
+            if let Some(_) = current_role {
+                if !current_content.is_empty() {
+                    current_content.push('\n');
+                }
+                current_content.push_str(line);
+            }
+        }
+
+        if let Some(role) = current_role {
+            messages.push(serde_json::json!({
+                "role": role,
+                "content": current_content.trim()
+            }));
+        }
+        messages
+    }
+}