feat: chat stats, regenerate with version history, edit & resubmit, image/file attachments

crates/engine/src/lib.rs

@@ -6,4 +6,4 @@ pub mod types;
 pub use error::{EngineError, Result};
 pub use manager::EngineManager;
 pub use remote::{stream_chat_remote, RemoteConfig};
-pub use types::{ChatMessage, ChatRequest, EngineConfig, EngineStatus};
+pub use types::{ChatMessage, ChatRequest, ChatStreamEvent, EngineConfig, EngineStatus};

crates/engine/src/manager.rs

@@ -1,5 +1,5 @@
 use crate::error::{EngineError, Result};
-use crate::types::{ChatRequest, EngineConfig, EngineStatus};
+use crate::types::{ChatRequest, ChatStreamEvent, EngineConfig, EngineStatus};
 use futures::Stream;
 use std::process::Stdio;
 use std::sync::Arc;
@@ -145,7 +145,7 @@ impl EngineManager {
     pub async fn stream_chat(
         &self,
         req: ChatRequest,
-    ) -> Result<futures::stream::BoxStream<'static, Result<String>>> {
+    ) -> Result<futures::stream::BoxStream<'static, Result<ChatStreamEvent>>> {
         let guard = self.inner.lock().await;
         let handle = guard.as_ref().ok_or(EngineError::NotRunning)?;
         let url = format!("{}/v1/chat/completions", handle.base_url);
@@ -211,7 +211,7 @@ pub(crate) fn sse_text_stream(
         + Unpin
         + Send
         + 'static,
-) -> futures::stream::BoxStream<'static, Result<String>> {
+) -> futures::stream::BoxStream<'static, Result<ChatStreamEvent>> {
     use futures::StreamExt;
 
     Box::pin(async_stream::stream! {
@@ -251,12 +251,26 @@ pub(crate) fn sse_text_stream(
                             closed = true;
                             break;
                         }
+                        if let Some(usage) = value.get("usage") {
+                            let prompt_tokens = usage
+                                .get("prompt_tokens")
+                                .and_then(|v| v.as_u64())
+                                .unwrap_or(0) as u32;
+                            let completion_tokens = usage
+                                .get("completion_tokens")
+                                .and_then(|v| v.as_u64())
+                                .unwrap_or(0) as u32;
+                            yield Ok(ChatStreamEvent::Usage {
+                                prompt_tokens,
+                                completion_tokens,
+                            });
+                        }
                         let content = value
                             .pointer("/choices/0/delta/content")
                             .and_then(|v| v.as_str())
                             .or_else(|| value.get("content").and_then(|v| v.as_str()));
                         if let Some(text) = content {
-                            yield Ok(text.to_string());
+                            yield Ok(ChatStreamEvent::Text(text.to_string()));
                         }
                     }
                     Err(e) => {

crates/engine/src/remote.rs

@@ -1,6 +1,6 @@
 use crate::error::{EngineError, Result};
 use crate::manager::sse_text_stream;
-use crate::types::ChatRequest;
+use crate::types::{ChatRequest, ChatStreamEvent};
 
 /// OpenAI 兼容的远程模型端点配置。
 #[derive(Debug, Clone)]
@@ -14,7 +14,7 @@ pub struct RemoteConfig {
 pub async fn stream_chat_remote(
     cfg: &RemoteConfig,
     req: ChatRequest,
-) -> Result<futures::stream::BoxStream<'static, Result<String>>> {
+) -> Result<futures::stream::BoxStream<'static, Result<ChatStreamEvent>>> {
     let base = normalize_base(&cfg.base_url);
     let url = format!("{base}/chat/completions");
     let client = reqwest::Client::new();
@@ -41,4 +41,3 @@ fn normalize_base(base: &str) -> String {
     }
     s
 }
-

crates/engine/src/types.rs

@@ -1,10 +1,64 @@
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+use serde::ser::SerializeMap;
+
+#[derive(Debug, Clone, Deserialize)]
 pub struct ChatMessage {
     pub role: String,
     pub content: String,
+    /// 图片（data URL），非空时序列化为多模态 content 数组
+    #[serde(default)]
+    pub images: Vec<String>,
+}
+
+impl ChatMessage {
+    pub fn new(role: impl Into<String>, content: impl Into<String>) -> Self {
+        Self {
+            role: role.into(),
+            content: content.into(),
+            images: Vec::new(),
+        }
+    }
+}
+
+impl Serialize for ChatMessage {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let mut map = serializer.serialize_map(Some(1))?;
+        map.serialize_entry("role", &self.role)?;
+        if self.images.is_empty() {
+            map.serialize_entry("content", &self.content)?;
+        } else {
+            let mut parts = Vec::new();
+            if !self.content.trim().is_empty() {
+                parts.push(serde_json::json!({
+                    "type": "text",
+                    "text": self.content,
+                }));
+            }
+            for image in &self.images {
+                parts.push(serde_json::json!({
+                    "type": "image_url",
+                    "image_url": { "url": image },
+                }));
+            }
+            map.serialize_entry("content", &parts)?;
+        }
+        map.end()
+    }
+}
+
+/// 流式聊天事件：增量文本 或 用量统计（部分引擎在最后一条 SSE 里给出）。
+#[derive(Debug, Clone)]
+pub enum ChatStreamEvent {
+    Text(String),
+    Usage {
+        prompt_tokens: u32,
+        completion_tokens: u32,
+    },
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -57,4 +111,3 @@ pub struct EngineStatus {
     pub ngl: Option<i32>,
     pub uptime_secs: Option<u64>,
 }
-