refactor: extract ResponseData struct to eliminate 18-arg build_response_object

src/api/responses.rs

@@ -65,55 +65,51 @@ fn extract_conversation_id(conv: &Option<serde_json::Value>) -> Option<String> {
     }
 }
 
-/// Build a full Response object matching the official OpenAI schema.
+/// Response-specific data for building a Response object.
-fn build_response_object(
+struct ResponseData {
-    id: &str,
+    id: String,
-    model: &str,
+    model: String,
     status: &'static str,
     created_at: u64,
     completed_at: Option<u64>,
     output: Vec<ResponseOutput>,
     usage: Option<Usage>,
-    instructions: Option<&str>,
-    store: bool,
-    temperature: f64,
-    top_p: f64,
-    max_output_tokens: Option<u64>,
-    previous_response_id: Option<&str>,
-    user: Option<&str>,
-    metadata: &serde_json::Value,
     thinking_signature: Option<String>,
     thinking: Option<String>,
     thinking_duration: Option<String>,
-) -> ResponsesResponse {
+}
+
+/// Build a full Response object matching the official OpenAI schema.
+#[allow(clippy::too_many_arguments)]
+fn build_response_object(data: ResponseData, params: &RequestParams) -> ResponsesResponse {
     ResponsesResponse {
-        id: id.to_string(),
+        id: data.id,
         object: "response",
-        created_at,
+        created_at: data.created_at,
-        status,
+        status: data.status,
-        completed_at,
+        completed_at: data.completed_at,
         error: None,
         incomplete_details: None,
-        instructions: instructions.map(|s| s.to_string()),
+        instructions: params.instructions.clone(),
-        max_output_tokens,
+        max_output_tokens: params.max_output_tokens,
-        model: model.to_string(),
+        model: data.model,
-        output,
+        output: data.output,
         parallel_tool_calls: true,
-        previous_response_id: previous_response_id.map(|s| s.to_string()),
+        previous_response_id: params.previous_response_id.clone(),
         reasoning: Reasoning::default(),
-        store,
+        store: params.store,
-        temperature,
+        temperature: params.temperature,
         text: TextFormat::default(),
         tool_choice: "auto",
         tools: vec![],
-        top_p,
+        top_p: params.top_p,
         truncation: "disabled",
-        usage,
+        usage: data.usage,
-        user: user.map(|s| s.to_string()),
+        user: params.user.clone(),
-        metadata: metadata.clone(),
+        metadata: params.metadata.clone(),
-        thinking_signature,
+        thinking_signature: data.thinking_signature,
-        thinking,
+        thinking: data.thinking,
-        thinking_duration,
+        thinking_duration: data.thinking_duration,
     }
 }
 
@@ -340,34 +336,29 @@ async fn handle_responses_sync(
     let usage = usage_from_poll(&state.mitm_store, &cascade_id, &poll_result.usage, &params.user_text, &poll_result.text).await;
 
     let resp = build_response_object(
-        &response_id,
+        ResponseData {
-        &model_name,
+            id: response_id,
-        "completed",
+            model: model_name,
-        created_at,
-        Some(completed_at),
-        vec![ResponseOutput {
-            output_type: "message",
-            id: msg_id,
             status: "completed",
-            role: "assistant",
+            created_at,
-            content: vec![OutputContent {
+            completed_at: Some(completed_at),
-                content_type: "output_text",
+            output: vec![ResponseOutput {
-                text: poll_result.text,
+                output_type: "message",
-                annotations: vec![],
+                id: msg_id,
+                status: "completed",
+                role: "assistant",
+                content: vec![OutputContent {
+                    content_type: "output_text",
+                    text: poll_result.text,
+                    annotations: vec![],
+                }],
             }],
-        }],
+            usage: Some(usage),
-        Some(usage),
+            thinking_signature: poll_result.thinking_signature,
-        params.instructions.as_deref(),
+            thinking: poll_result.thinking,
-        params.store,
+            thinking_duration: poll_result.thinking_duration,
-        params.temperature,
+        },
-        params.top_p,
+        &params,
-        params.max_output_tokens,
-        params.previous_response_id.as_deref(),
-        params.user.as_deref(),
-        &params.metadata,
-        poll_result.thinking_signature,
-        poll_result.thinking,
-        poll_result.thinking_duration,
     );
 
     Json(resp).into_response()
@@ -393,13 +384,19 @@ async fn handle_responses_stream(
 
         // Build the in-progress response shell (no output yet)
         let in_progress_resp = build_response_object(
-            &response_id, &model_name, "in_progress", created_at, None,
+            ResponseData {
-            vec![], None,
+                id: response_id.clone(),
-            params.instructions.as_deref(), params.store,
+                model: model_name.clone(),
-            params.temperature, params.top_p,
+                status: "in_progress",
-            params.max_output_tokens, params.previous_response_id.as_deref(),
+                created_at,
-            params.user.as_deref(), &params.metadata,
+                completed_at: None,
-            None, None, None,
+                output: vec![],
+                usage: None,
+                thinking_signature: None,
+                thinking: None,
+                thinking_duration: None,
+            },
+            &params,
         );
         let resp_json = response_to_json(&in_progress_resp);
 
@@ -544,13 +541,19 @@ async fn handle_responses_stream(
 
         // Timeout — emit incomplete response
         let timeout_resp = build_response_object(
-            &response_id, &model_name, "incomplete", created_at, None,
+            ResponseData {
-            vec![], Some(Usage::estimate(&params.user_text, "")),
+                id: response_id.clone(),
-            params.instructions.as_deref(), params.store,
+                model: model_name.clone(),
-            params.temperature, params.top_p,
+                status: "incomplete",
-            params.max_output_tokens, params.previous_response_id.as_deref(),
+                created_at,
-            params.user.as_deref(), &params.metadata,
+                completed_at: None,
-            None, None, None,
+                output: vec![],
+                usage: Some(Usage::estimate(&params.user_text, "")),
+                thinking_signature: None,
+                thinking: None,
+                thinking_duration: None,
+            },
+            &params,
         );
         yield Ok(responses_sse_event(
             "response.completed",
@@ -578,6 +581,7 @@ async fn handle_responses_stream(
 /// 2. response.content_part.done
 /// 3. response.output_item.done
 /// 4. response.completed
+#[allow(clippy::too_many_arguments)]
 fn completion_events(
     resp_id: &str,
     model: &str,
@@ -609,30 +613,29 @@ fn completion_events(
     });
 
     let completed_resp = build_response_object(
-        resp_id, model, "completed", created_at, Some(completed_at),
+        ResponseData {
-        vec![ResponseOutput {
+            id: resp_id.to_string(),
-            output_type: "message",
+            model: model.to_string(),
-            id: msg_id.to_string(),
             status: "completed",
-            role: "assistant",
+            created_at,
-            content: vec![OutputContent {
+            completed_at: Some(completed_at),
-                content_type: "output_text",
+            output: vec![ResponseOutput {
-                text: text.to_string(),
+                output_type: "message",
-                annotations: vec![],
+                id: msg_id.to_string(),
+                status: "completed",
+                role: "assistant",
+                content: vec![OutputContent {
+                    content_type: "output_text",
+                    text: text.to_string(),
+                    annotations: vec![],
+                }],
             }],
-        }],
+            usage: Some(usage),
-        Some(usage),
+            thinking_signature,
-        params.instructions.as_deref(),
+            thinking,
-        params.store,
+            thinking_duration,
-        params.temperature,
+        },
-        params.top_p,
+        params,
-        params.max_output_tokens,
-        params.previous_response_id.as_deref(),
-        params.user.as_deref(),
-        &params.metadata,
-        thinking_signature,
-        thinking,
-        thinking_duration,
     );
 
     vec![