重构: 巨函数拆分 + 清理历史标记注释 + custom_prompt/停止按钮/tunnel 改进

src-tauri/src/commands/ai/stream_recv.rs

@@ -123,6 +123,31 @@ pub(crate) enum StreamResult {
     InitFailed { retryable: bool, error: String },
 }
 
+/// 将 chunk 携带的 tool_calls delta 累加到累积表。
+///
+/// 每个 `ToolCallDelta` 按 `index` 归位到同一个 `ToolCallDraft`：
+/// - `id` 覆盖(后到的 id 视为权威,匹配 OpenAI/Anthropic 协议行为)
+/// - `function_name` / `function_arguments` 增量拼接(流式分片到达)
+///
+/// 抽取自 stream_llm 的 chunk match arm(原最深 7 层嵌套点),纯状态累加无 emit/return 副作用。
+fn accumulate_tool_calls(
+    tc_deltas: &[df_ai::provider::ToolCallDelta],
+    tool_calls_acc: &mut HashMap<u32, ToolCallDraft>,
+) {
+    for tc_delta in tc_deltas {
+        let draft = tool_calls_acc.entry(tc_delta.index).or_default();
+        if let Some(id) = &tc_delta.id {
+            draft.id = id.clone();
+        }
+        if let Some(name) = &tc_delta.function_name {
+            draft.name.push_str(name);
+        }
+        if let Some(args) = &tc_delta.function_arguments {
+            draft.args.push_str(args);
+        }
+    }
+}
+
 /// 流式接收 LLM 响应。
 ///
 /// 三类异常处理（返回 StreamResult 显式区分出口）：
@@ -339,12 +364,7 @@ pub(crate) async fn stream_llm(
                             let _ = app_handle.state::<crate::state::AppState>().ai_event_bus.publish_event(ev);
                         }
                         if let Some(tc_deltas) = &chunk.tool_calls {
-                            for tc_delta in tc_deltas {
-                                let draft = tool_calls_acc.entry(tc_delta.index).or_default();
-                                if let Some(id) = &tc_delta.id { draft.id = id.clone(); }
-                                if let Some(name) = &tc_delta.function_name { draft.name.push_str(name); }
-                                if let Some(args) = &tc_delta.function_arguments { draft.args.push_str(args); }
-                            }
+                            accumulate_tool_calls(tc_deltas, &mut tool_calls_acc);
                         }
                         if let Some(u) = &chunk.usage {
                             final_usage = Some(u.clone());