From 3f728c4737dd69eb09d2a98360f496a9da79edc7 Mon Sep 17 00:00:00 2001
From: xsigoking <152482559+xsigoking@users.noreply.github.com>
Date: Sun, 21 Apr 2024 22:30:14 +0000
Subject: [PATCH] feat: support history messages (#15)

---
 src/main.rs | 47 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 36 insertions(+), 11 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 9d8d3bb..aaa8e69 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -204,14 +204,16 @@ impl Server {
             .map_err(|err| anyhow!("Invalid request body, {err}"))?;
 
         let is_stream = req_body["stream"].as_bool().unwrap_or_default();
+        let mut invalid = false;
         let mut new_messages = vec![];
-        let mut invalid_messages = false;
+        let mut system_prompt = None;
         if let Some(messages) = req_body["messages"].as_array() {
+            let has_history = messages.len() > 2;
             for v in messages {
                 let role = match v["role"].as_str() {
                     Some(v) => v,
                     None => {
-                        invalid_messages = true;
+                        invalid = true;
                         break;
                     }
                 };
@@ -228,27 +230,50 @@ impl Server {
                         _ => "",
                     };
                     if text.is_empty() {
-                        invalid_messages = true;
+                        invalid = true;
                         break;
                     }
                     text
                 };
-                new_messages.push(json!({
-                    "id": random_id(),
-                    "author": { "role": role },
-                    "content": { "content_type": "text", "parts": [content] },
-                    "metadata": {},
-                }));
+                if role == "system" {
+                    if system_prompt.is_some() {
+                        invalid = true;
+                        break;
+                    }
+                    system_prompt = Some(content.to_string());
+                } else if role == "user" && has_history {
+                    new_messages.push(format!("[INST]{content}[/INST]"));
+                } else {
+                    new_messages.push(content.to_string());
+                }
             }
         }
 
-        if invalid_messages {
+        if invalid {
             bail!("Invalid request messages");
         }
 
+        let mut messages = vec![];
+        if let Some(system_prompt) = system_prompt {
+            messages.push(json!({
+                "id": random_id(),
+                "author": { "role": "system" },
+                "content": { "content_type": "text", "parts": [system_prompt] },
+                "metadata": {},
+            }))
+        }
+
+        let combine_message = new_messages.join("\n");
+        messages.push(json!({
+            "id": random_id(),
+            "author": { "role": "user" },
+            "content": { "content_type": "text", "parts": [combine_message] },
+            "metadata": {},
+        }));
+
         let req_body = json!({
             "action": "next",
-            "messages": new_messages,
+            "messages": messages,
             "parent_message_id": random_id(),
             "model": "text-davinci-002-render-sha",
             "timezone_offset_min": 0,