feat: add streaming responses for anthropic and openai

internal/service/service.go

@@ -60,6 +60,15 @@ type ChatResult struct {
 	EffectiveSession SessionMode
 }
 
+type StreamEvent struct {
+	Delta string
+}
+
+type StreamResult struct {
+	Result *ChatResult
+	Err    error
+}
+
 type Model struct {
 	ID    string `json:"id"`
 	Name  string `json:"name"`
@@ -151,7 +160,39 @@ func (s *Service) ListModels(ctx context.Context) ([]Model, error) {
 func (s *Service) Generate(ctx context.Context, req ChatRequest) (*ChatResult, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	return s.generateLocked(ctx, req, nil)
+}
 
+func (s *Service) GenerateStream(ctx context.Context, req ChatRequest) (<-chan StreamEvent, <-chan StreamResult, error) {
+	events := make(chan StreamEvent, 256)
+	done := make(chan StreamResult, 1)
+
+	go func() {
+		s.mu.Lock()
+		result, err := s.generateLocked(ctx, req, func(delta string) {
+			if delta == "" {
+				return
+			}
+			select {
+			case events <- StreamEvent{Delta: delta}:
+			case <-ctx.Done():
+			}
+		})
+		s.mu.Unlock()
+
+		close(events)
+		done <- StreamResult{Result: result, Err: err}
+		close(done)
+	}()
+
+	return events, done, nil
+}
+
+func (s *Service) generateLocked(
+	ctx context.Context,
+	req ChatRequest,
+	onDelta func(string),
+) (*ChatResult, error) {
 	requestCtx, cancel := context.WithTimeout(ctx, s.cfg.Timeout)
 	defer cancel()
 
@@ -198,7 +239,7 @@ func (s *Service) Generate(ctx context.Context, req ChatRequest) (*ChatResult, e
 		}
 	}
 
-	runResult, err := s.runPromptLocked(requestCtx, ipcClient, sessionID, prompt, requestID, meta)
+	runResult, err := s.runPromptLocked(requestCtx, ipcClient, sessionID, prompt, requestID, meta, onDelta)
 	if err != nil {
 		if effectiveMode == SessionModeReuse {
 			s.stickySessionID = ""
@@ -220,7 +261,18 @@ func (s *Service) Generate(ctx context.Context, req ChatRequest) (*ChatResult, e
 		return nil, fmt.Errorf("Lingma IPC response remained incomplete before timeout. Partial reply: %s", truncate(runResult.AssistantText, 120))
 	}
 
-	result := &ChatResult{
+	return s.buildChatResult(req, sessionID, requestID, prompt, runResult, effectiveMode), nil
+}
+
+func (s *Service) buildChatResult(
+	req ChatRequest,
+	sessionID string,
+	requestID string,
+	prompt string,
+	runResult *promptRunResult,
+	effectiveMode SessionMode,
+) *ChatResult {
+	return &ChatResult{
 		Text:             runResult.AssistantText,
 		Model:            valueOr(strings.TrimSpace(req.Model), "lingma"),
 		InputTokens:      estimateTokens(prompt),
@@ -234,7 +286,6 @@ func (s *Service) Generate(ctx context.Context, req ChatRequest) (*ChatResult, e
 		PipePath:         s.pipePath,
 		EffectiveSession: effectiveMode,
 	}
-	return result, nil
 }
 
 func (s *Service) ensureConnectedLocked(ctx context.Context) (*lingmaipc.Client, error) {
@@ -322,6 +373,7 @@ func (s *Service) runPromptLocked(
 	text string,
 	requestID string,
 	meta map[string]any,
+	onDelta func(string),
 ) (*promptRunResult, error) {
 	notifications, cancel := client.Subscribe()
 	defer cancel()
@@ -367,6 +419,9 @@ func (s *Service) runPromptLocked(
 				chunk := nestedString(nestedMap(update, "content"), "text")
 				if chunk != "" {
 					builder.WriteString(chunk)
+					if onDelta != nil {
+						onDelta(chunk)
+					}
 				}
 			case "notification":
 				switch nestedString(update, "type") {