fix: preserve openai reasoning live stops

crates/llm-worker/src/llm_client/scheme/openai_responses/events.rs

@@ -25,8 +25,8 @@ pub struct OpenAIResponsesState {
     next_index: usize,
     /// 蓄積中の reasoning output_item。`output_item.added`(Reasoning) で
     /// 確保し、`reasoning_text.delta` / `reasoning_summary_text.delta` で
-    /// 蓄積、`output_item.done`(Reasoning) で metadata-only Thinking block を
-    /// 完了させて reasoning persistence material を渡す。
+    /// 蓄積、`output_item.done`(Reasoning) で既存 reasoning_text block または
+    /// metadata-only Thinking block に reasoning persistence material を載せる。
     pending_reasoning: HashMap<usize, PendingReasoning>,
 }
 
@@ -38,6 +38,24 @@ struct PendingReasoning {
     text: String,
     /// `reasoning_summary_text.delta` を summary_index 順に蓄積。
     summary: Vec<String>,
+    /// `response.content_part.done` が先に到着した reasoning/thinking block。
+    ///
+    /// `response.output_item.done` まで待たないと encrypted_content や最終
+    /// summary が揃わないため、live-visible な余分な synthetic Thinking block
+    /// を作らず、既存 block の stop に persistence metadata を載せる。
+    deferred_thinking_stops: Vec<SlotInfo>,
+}
+
+impl PendingReasoning {
+    fn into_reasoning_data(self, encrypted_content: Option<String>) -> ReasoningBlockData {
+        ReasoningBlockData {
+            id: self.id,
+            text: Some(self.text),
+            summary: self.summary.into_iter().filter(|s| !s.is_empty()).collect(),
+            encrypted_content,
+            signature: None,
+        }
+    }
 }
 
 impl OpenAIResponsesState {
@@ -73,6 +91,31 @@ impl OpenAIResponsesState {
         }
         entry.summary[summary_index].push_str(text);
     }
+
+    fn defer_reasoning_stop(&mut self, output_index: usize, info: SlotInfo) {
+        self.ensure_reasoning(output_index)
+            .deferred_thinking_stops
+            .push(info);
+    }
+
+    fn take_active_reasoning_slots(&mut self, output_index: usize) -> Vec<SlotInfo> {
+        let mut keys: Vec<_> = self
+            .slots
+            .iter()
+            .filter_map(|(key, info)| match key {
+                SlotKey::ContentPart { output, content }
+                    if *output == output_index && info.block_type == BlockType::Thinking =>
+                {
+                    Some((*content, *key))
+                }
+                _ => None,
+            })
+            .collect();
+        keys.sort_by_key(|(content, _)| *content);
+        keys.into_iter()
+            .filter_map(|(_, key)| self.slots.remove(&key))
+            .collect()
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -380,9 +423,10 @@ pub(crate) fn parse_sse(
 
         "response.output_item.done" => {
             let ev: OutputItemDone = from_json(data)?;
-            // Reasoning wrapper の done で蓄積分を metadata-only Thinking block
-            // stop に載せる。これは `slots` の OutputItem slot とは独立している
-            // (FunctionCall は slots、Reasoning は pending_reasoning)。
+            // Reasoning wrapper の done で蓄積分を既存 reasoning_text block の
+            // stop に載せる。content_part.done が先に来た場合は stop を defer
+            // しておき、ここで encrypted_content / summary と一緒に完了させる。
+            // reasoning_text が無い metadata-only item だけ synthetic block を作る。
             if let OutputItem::Reasoning {
                 id,
                 encrypted_content,
@@ -396,32 +440,43 @@ pub(crate) fn parse_sse(
                 if pending.id.is_none() {
                     pending.id = id;
                 }
-                let info =
-                    state.allocate(SlotKey::OutputItem(ev.output_index), BlockType::Thinking);
-                state.slots.remove(&SlotKey::OutputItem(ev.output_index));
-                return Ok(vec![
-                    Event::BlockStart(BlockStart {
-                        index: info.flat_index,
-                        block_type: BlockType::Thinking,
-                        metadata: BlockMetadata::Thinking,
-                    }),
-                    Event::BlockStop(BlockStop {
-                        index: info.flat_index,
-                        block_type: BlockType::Thinking,
-                        stop_reason: None,
-                        reasoning: Some(ReasoningBlockData {
-                            id: pending.id,
-                            text: Some(pending.text),
-                            summary: pending
-                                .summary
-                                .into_iter()
-                                .filter(|s| !s.is_empty())
-                                .collect(),
-                            encrypted_content,
-                            signature: None,
+
+                let mut stop_blocks = std::mem::take(&mut pending.deferred_thinking_stops);
+                stop_blocks.extend(state.take_active_reasoning_slots(ev.output_index));
+                let reasoning = pending.into_reasoning_data(encrypted_content);
+
+                if stop_blocks.is_empty() {
+                    let info =
+                        state.allocate(SlotKey::OutputItem(ev.output_index), BlockType::Thinking);
+                    state.slots.remove(&SlotKey::OutputItem(ev.output_index));
+                    return Ok(vec![
+                        Event::BlockStart(BlockStart {
+                            index: info.flat_index,
+                            block_type: BlockType::Thinking,
+                            metadata: BlockMetadata::Thinking,
                         }),
-                    }),
-                ]);
+                        Event::BlockStop(BlockStop {
+                            index: info.flat_index,
+                            block_type: BlockType::Thinking,
+                            stop_reason: None,
+                            reasoning: Some(reasoning),
+                        }),
+                    ]);
+                }
+
+                let last = stop_blocks.len() - 1;
+                return Ok(stop_blocks
+                    .into_iter()
+                    .enumerate()
+                    .map(|(idx, info)| {
+                        Event::BlockStop(BlockStop {
+                            index: info.flat_index,
+                            block_type: info.block_type,
+                            stop_reason: None,
+                            reasoning: (idx == last).then(|| reasoning.clone()),
+                        })
+                    })
+                    .collect());
             }
             if let Some(info) = state.slots.remove(&SlotKey::OutputItem(ev.output_index)) {
                 Ok(vec![Event::BlockStop(BlockStop {
@@ -462,12 +517,19 @@ pub(crate) fn parse_sse(
                 output: ev.output_index,
                 content: ev.content_index,
             }) {
-                Ok(vec![Event::BlockStop(BlockStop {
-                    index: info.flat_index,
-                    block_type: info.block_type,
-                    stop_reason: None,
-                    reasoning: None,
-                })])
+                if matches!(ev.part, ContentPart::ReasoningText { .. })
+                    || info.block_type == BlockType::Thinking
+                {
+                    state.defer_reasoning_stop(ev.output_index, info);
+                    Ok(Vec::new())
+                } else {
+                    Ok(vec![Event::BlockStop(BlockStop {
+                        index: info.flat_index,
+                        block_type: info.block_type,
+                        stop_reason: None,
+                        reasoning: None,
+                    })])
+                }
             } else {
                 Ok(Vec::new())
             }
@@ -1146,11 +1208,15 @@ mod tests {
             r#"{"output_index":0,"item":{"type":"reasoning","id":"r1"}}"#,
         );
         // 内側の reasoning_text 用 content_part
-        with(
+        let start = with(
             &mut state,
             "response.content_part.added",
             r#"{"output_index":0,"content_index":0,"item_id":"r1","part":{"type":"reasoning_text","text":""}}"#,
         );
+        let start_index = match start.as_slice() {
+            [Event::BlockStart(start)] => start.index,
+            other => panic!("expected one BlockStart, got {other:?}"),
+        };
         with(
             &mut state,
             "response.reasoning_text.delta",
@@ -1161,11 +1227,12 @@ mod tests {
             "response.reasoning_text.delta",
             r#"{"output_index":0,"content_index":0,"item_id":"r1","delta":"world"}"#,
         );
-        with(
+        let part_done = with(
             &mut state,
             "response.content_part.done",
             r#"{"output_index":0,"content_index":0,"item_id":"r1","part":{"type":"reasoning_text","text":"hello world"}}"#,
         );
+        assert!(part_done.is_empty());
         // summary 1 件
         with(
             &mut state,
@@ -1189,11 +1256,11 @@ mod tests {
             "response.output_item.done",
             r#"{"output_index":0,"item":{"type":"reasoning","id":"r1","encrypted_content":"ENC-XYZ"}}"#,
         );
-        assert_eq!(evs.len(), 2);
-        assert!(matches!(evs[0], Event::BlockStart(_)));
-        let Event::BlockStop(stop) = &evs[1] else {
-            panic!("expected BlockStop, got {:?}", evs[1]);
+        assert_eq!(evs.len(), 1);
+        let Event::BlockStop(stop) = &evs[0] else {
+            panic!("expected BlockStop, got {:?}", evs[0]);
         };
+        assert_eq!(stop.index, start_index);
         let reasoning = stop.reasoning.as_ref().expect("reasoning metadata");
         assert_eq!(reasoning.id.as_deref(), Some("r1"));
         assert_eq!(reasoning.text.as_deref(), Some("hello world"));
@@ -1204,6 +1271,90 @@ mod tests {
         assert!(state.pending_reasoning.is_empty());
     }
 
+    #[test]
+    fn reasoning_text_done_then_output_done_emits_single_existing_block_stop() {
+        let mut state = OpenAIResponsesState::default();
+        with(
+            &mut state,
+            "response.output_item.added",
+            r#"{"output_index":0,"item":{"type":"reasoning","id":"r1"}}"#,
+        );
+
+        let mut lifecycle = Vec::new();
+        lifecycle.extend(with(
+            &mut state,
+            "response.content_part.added",
+            r#"{"output_index":0,"content_index":0,"item_id":"r1","part":{"type":"reasoning_text","text":""}}"#,
+        ));
+        lifecycle.extend(with(
+            &mut state,
+            "response.reasoning_text.delta",
+            r#"{"output_index":0,"content_index":0,"item_id":"r1","delta":"think"}"#,
+        ));
+        lifecycle.extend(with(
+            &mut state,
+            "response.content_part.done",
+            r#"{"output_index":0,"content_index":0,"item_id":"r1","part":{"type":"reasoning_text","text":"think"}}"#,
+        ));
+        lifecycle.extend(with(
+            &mut state,
+            "response.output_item.done",
+            r#"{"output_index":0,"item":{"type":"reasoning","id":"r1","encrypted_content":"ENC"}}"#,
+        ));
+
+        let starts: Vec<_> = lifecycle
+            .iter()
+            .filter_map(|event| match event {
+                Event::BlockStart(start) => Some(start.index),
+                _ => None,
+            })
+            .collect();
+        let stops: Vec<_> = lifecycle
+            .iter()
+            .filter_map(|event| match event {
+                Event::BlockStop(stop) => Some(stop),
+                _ => None,
+            })
+            .collect();
+
+        assert_eq!(starts.len(), 1, "no synthetic second Thinking start");
+        assert_eq!(stops.len(), 1, "no duplicate empty Thinking stop");
+        assert_eq!(stops[0].index, starts[0]);
+        let reasoning = stops[0].reasoning.as_ref().expect("reasoning metadata");
+        assert_eq!(reasoning.text.as_deref(), Some("think"));
+        assert_eq!(reasoning.encrypted_content.as_deref(), Some("ENC"));
+
+        struct StopRecorder(std::sync::Arc<std::sync::Mutex<Vec<(usize, String, bool)>>>);
+        impl crate::handler::Handler<crate::handler::ThinkingBlockKind> for StopRecorder {
+            type Scope = String;
+
+            fn on_event(
+                &mut self,
+                scope: &mut Self::Scope,
+                event: &crate::handler::ThinkingBlockEvent,
+            ) {
+                match event {
+                    crate::handler::ThinkingBlockEvent::Start(_) => scope.clear(),
+                    crate::handler::ThinkingBlockEvent::Delta(delta) => scope.push_str(delta),
+                    crate::handler::ThinkingBlockEvent::Stop(stop) => self
+                        .0
+                        .lock()
+                        .unwrap()
+                        .push((stop.index, scope.clone(), stop.reasoning.is_some())),
+                }
+            }
+        }
+
+        let stops = std::sync::Arc::new(std::sync::Mutex::new(Vec::new()));
+        let mut timeline = crate::timeline::Timeline::new();
+        timeline.on_thinking_block(StopRecorder(stops.clone()));
+        for event in &lifecycle {
+            timeline.dispatch(event);
+        }
+        let stops = stops.lock().unwrap().clone();
+        assert_eq!(stops, vec![(starts[0], "think".to_string(), true)]);
+    }
+
     #[test]
     fn reasoning_wrapper_without_inner_content_emits_empty_text() {
         // encrypted_content だけ届く（reasoning_text 無し）ケースでも

crates/llm-worker/src/timeline/timeline.rs

@@ -3,7 +3,7 @@
 //! LLMからのイベントストリームを受信し、登録されたHandlerにディスパッチします。
 //! 通常はWorker経由で使用しますが、直接使用することも可能です。
 
-use std::marker::PhantomData;
+use std::{collections::HashMap, marker::PhantomData};
 
 use super::event::*;
 use crate::handler::*;
@@ -189,7 +189,7 @@ where
     H: Handler<ThinkingBlockKind>,
 {
     handler: H,
-    scope: Option<H::Scope>,
+    scopes: HashMap<usize, H::Scope>,
 }
 
 impl<H> ThinkingBlockHandlerWrapper<H>
@@ -199,7 +199,7 @@ where
     fn new(handler: H) -> Self {
         Self {
             handler,
-            scope: None,
+            scopes: HashMap::new(),
         }
     }
 }
@@ -210,27 +210,25 @@ where
     H::Scope: Send + Sync,
 {
     fn dispatch_start(&mut self, start: &BlockStart) {
-        if let Some(scope) = &mut self.scope {
-            self.handler.on_event(
-                scope,
-                &ThinkingBlockEvent::Start(ThinkingBlockStart { index: start.index }),
-            );
-        }
+        let scope = self.scopes.entry(start.index).or_default();
+        self.handler.on_event(
+            scope,
+            &ThinkingBlockEvent::Start(ThinkingBlockStart { index: start.index }),
+        );
     }
 
     fn dispatch_delta(&mut self, delta: &BlockDelta) {
-        if let Some(scope) = &mut self.scope {
-            if let DeltaContent::Thinking(text) = &delta.delta {
-                self.handler
-                    .on_event(scope, &ThinkingBlockEvent::Delta(text.clone()));
-            }
+        if let DeltaContent::Thinking(text) = &delta.delta {
+            let scope = self.scopes.entry(delta.index).or_default();
+            self.handler
+                .on_event(scope, &ThinkingBlockEvent::Delta(text.clone()));
         }
     }
 
     fn dispatch_stop(&mut self, stop: &BlockStop) {
-        if let Some(scope) = &mut self.scope {
+        if let Some(mut scope) = self.scopes.remove(&stop.index) {
             self.handler.on_event(
-                scope,
+                &mut scope,
                 &ThinkingBlockEvent::Stop(ThinkingBlockStop {
                     index: stop.index,
                     reasoning: stop.reasoning.clone(),
@@ -239,18 +237,16 @@ where
         }
     }
 
-    fn dispatch_abort(&mut self, _abort: &BlockAbort) {}
-
-    fn start_scope(&mut self) {
-        self.scope = Some(H::Scope::default());
+    fn dispatch_abort(&mut self, _abort: &BlockAbort) {
+        self.scopes.clear();
     }
 
-    fn end_scope(&mut self) {
-        self.scope = None;
-    }
+    fn start_scope(&mut self) {}
+
+    fn end_scope(&mut self) {}
 
     fn has_scope(&self) -> bool {
-        self.scope.is_some()
+        !self.scopes.is_empty()
     }
 }
 

work-items/open/20260603-001124-unify-reasoning-block-lifecycle/artifacts/implementation-report.md

@@ -0,0 +1,41 @@
+# Implementation report: reasoning block lifecycle
+
+## Investigation
+
+Initial implementation unified reasoning persistence through `BlockStop.reasoning`, but OpenAI Responses text-bearing reasoning items still had two Thinking lifecycles:
+
+1. `response.reasoning_text.delta` streamed through the real reasoning content-part block.
+2. `response.content_part.done` stopped that block with no persistence metadata.
+3. `response.output_item.done` emitted a second synthetic metadata-only Thinking `BlockStart`/`BlockStop` pair.
+
+That preserved persistence but changed live callback semantics: UI/trace consumers that listen to Thinking block stop callbacks could observe an extra empty Thinking stop after the real streamed reasoning block.
+
+## Fix summary
+
+OpenAI Responses now defers the stop for reasoning `content_part.done` when the part is a Thinking/reasoning-text content block. At `response.output_item.done`, the provider finalizes the deferred existing block with `ReasoningBlockData` instead of creating a second synthetic live-visible block.
+
+Thinking block handler scopes are also keyed by block index, so a deferred reasoning-text stop still uses its original streamed buffer even if another Thinking block (for example a reasoning summary block) starts and stops before `output_item.done`.
+
+Metadata-only reasoning items with no reasoning content-part still emit a synthetic metadata-bearing Thinking block so encrypted/id-only reasoning can be persisted and round-tripped.
+
+The fix preserves:
+
+- live `reasoning_text.delta` Thinking deltas;
+- OpenAI Responses `id`, `summary`, and `encrypted_content` persistence;
+- a single Thinking lifecycle for text-bearing reasoning items;
+- metadata-only reasoning coverage.
+
+## Validation
+
+Passed:
+
+- `cargo test -p llm-worker openai_responses::events::tests::reasoning --lib`
+- `cargo test -p llm-worker --lib`
+- `cargo check --workspace --all-targets`
+- `./tickets.sh doctor`
+- `git diff --check`
+- `nix build .#yoi`
+
+## Residual risk
+
+The provider delays the stop event for OpenAI Responses reasoning text blocks until `response.output_item.done` so final encrypted/summary metadata can be attached to the same block. This avoids duplicate live stops but means the block stop is slightly later than the raw `content_part.done` SSE for reasoning text. This is intentional for the unified persistence model and covered by focused provider tests for the reviewed sequence.