feat: wire answerability gate into ai runtime

internal/ai/runtime/executor/answerability_gate_test.go

@@ -186,6 +186,46 @@ func TestKnowledgeAnswerabilityGateEvaluateAllowsAnswerableDecisionAndProducesKn
 	}
 }
 
+func TestBuildRunMessagesReturnsFallbackWhenGateRejectsGrayZoneQuestion(t *testing.T) {
+	summary := &RunResult{}
+	question := "满足什么条件可以退款？"
+	gate := newTestKnowledgeAnswerabilityGate(newAnswerabilityRetrieverWithHit(), &fakeAnswerabilityChatModel{
+		response: `{"answerable": false, "reason": "retrieved snippets mention refunds but not the requested condition", "missingInfo": ["refund condition"]}`,
+	})
+
+	messages := buildRunMessages(context.Background(), newAnswerabilityGateRunInput(question, "1"), summary, nil, gate)
+
+	if !strings.Contains(summary.ReplyText, "建议你联系人工客服进一步确认。") {
+		t.Fatalf("expected human-support fallback, got %q", summary.ReplyText)
+	}
+	if messagesContainContent(messages, question) {
+		t.Fatalf("expected returned messages to omit current user message, got %#v", messages)
+	}
+}
+
+func TestBuildRunMessagesInjectsKnowledgeWhenGateAllows(t *testing.T) {
+	summary := &RunResult{}
+	question := "满足什么条件可以退款？"
+	gate := newTestKnowledgeAnswerabilityGate(newAnswerabilityRetrieverWithHit(), &fakeAnswerabilityChatModel{
+		response: `{"answerable": true, "reason": "refund condition is directly supported", "supportingChunkIds": ["101"]}`,
+	})
+
+	messages := buildRunMessages(context.Background(), newAnswerabilityGateRunInput(question, "1"), summary, nil, gate)
+
+	if summary.ReplyText != "" {
+		t.Fatalf("expected no fallback, got %q", summary.ReplyText)
+	}
+	if !messagesContainContent(messages, "知识库回答约束") {
+		t.Fatalf("expected knowledge instruction in messages, got %#v", messages)
+	}
+	if !messagesContainContent(messages, "购买后七天内且未使用可以退款。") {
+		t.Fatalf("expected knowledge context in messages, got %#v", messages)
+	}
+	if !messagesContainContent(messages, question) {
+		t.Fatalf("expected current user message in messages, got %#v", messages)
+	}
+}
+
 func newTestKnowledgeAnswerabilityGate(retriever knowledgeContextRetriever, chatModel model.BaseChatModel) *KnowledgeAnswerabilityGate {
 	return &KnowledgeAnswerabilityGate{
 		newRetriever: func(aiAgent models.AIAgent) knowledgeContextRetriever {
@@ -257,3 +297,12 @@ func (f *fakeAnswerabilityChatModel) Generate(ctx context.Context, input []*sche
 func (f *fakeAnswerabilityChatModel) Stream(ctx context.Context, input []*schema.Message, opts ...model.Option) (*schema.StreamReader[*schema.Message], error) {
 	return nil, errors.New("stream is not implemented in fakeAnswerabilityChatModel")
 }
+
+func messagesContainContent(messages []*schema.Message, text string) bool {
+	for _, message := range messages {
+		if message != nil && strings.Contains(message.Content, text) {
+			return true
+		}
+	}
+	return false
+}

internal/ai/runtime/executor/context_builders.go

@@ -6,13 +6,12 @@ import (
 
 	"cs-agent/internal/ai/runtime/internal/impl/adapter"
 	"cs-agent/internal/ai/runtime/internal/impl/callbacks"
-	"cs-agent/internal/ai/runtime/internal/impl/retrievers"
 	"cs-agent/internal/pkg/utils"
 
 	"github.com/cloudwego/eino/schema"
 )
 
-func buildRunMessages(ctx context.Context, req RunInput, summary *RunResult, collector *callbacks.RuntimeTraceCollector) []*schema.Message {
+func buildRunMessages(ctx context.Context, req RunInput, summary *RunResult, collector *callbacks.RuntimeTraceCollector, gate *KnowledgeAnswerabilityGate) []*schema.Message {
 	history := adapter.BuildHistoryMessages(req.Conversation.ID, req.UserMessage.ID, 12)
 	if summary != nil {
 		summary.HistoryMessageCount = len(history.Messages)
@@ -24,7 +23,7 @@ func buildRunMessages(ctx context.Context, req RunInput, summary *RunResult, col
 	}
 	messages := make([]*schema.Message, 0, len(history.Messages)+3)
 	messages = append(messages, history.Messages...)
-	decision := appendRetrievedContext(ctx, req, summary, collector, &messages)
+	decision := appendRetrievedContext(ctx, req, summary, collector, gate, &messages)
 	if strings.TrimSpace(decision.FallbackReply) != "" {
 		if summary != nil {
 			summary.ReplyText = decision.FallbackReply
@@ -35,30 +34,32 @@ func buildRunMessages(ctx context.Context, req RunInput, summary *RunResult, col
 	return messages
 }
 
-func appendRetrievedContext(ctx context.Context, req RunInput, summary *RunResult, collector *callbacks.RuntimeTraceCollector, messages *[]*schema.Message) knowledgeGuardDecision {
+func appendRetrievedContext(ctx context.Context, req RunInput, summary *RunResult, collector *callbacks.RuntimeTraceCollector, gate *KnowledgeAnswerabilityGate, messages *[]*schema.Message) knowledgeGuardDecision {
 	if messages == nil {
 		return knowledgeGuardDecision{}
 	}
-	retriever := retrievers.NewKnowledgeRetriever(req.AIAgent)
-	retrieveOptions := retrievers.DefaultKnowledgeRetrieveOptions()
-	retrieveOptions.QueryPreview = preview(req.UserMessage.Content, 120)
-	retrieveResult, retrieveErr := retriever.RetrieveContextByOptions(ctx, retrieveOptions, strings.TrimSpace(req.UserMessage.Content))
-	if retrieveErr != nil || retrieveResult == nil {
-		return buildKnowledgeUnavailableDecision(req.AIAgent, retriever.KnowledgeBaseIDs())
+	if gate == nil {
+		gate = NewKnowledgeAnswerabilityGate()
 	}
-	if summary != nil {
-		summary.RetrieverCount = len(retrieveResult.Hits)
+	state, err := gate.Evaluate(ctx, answerabilityGateInput{
+		Request:   req,
+		Summary:   summary,
+		Collector: collector,
+		Messages:  append([]*schema.Message(nil), (*messages)...),
+	})
+	if err != nil || state == nil {
+		decision := buildKnowledgeUnavailableDecision(req.AIAgent, utils.SplitInt64s(req.AIAgent.KnowledgeIDs))
+		if strings.TrimSpace(decision.FallbackReply) != "" {
+			decision.FallbackReply = resolveKnowledgeHumanSupportFallback(req.AIAgent)
+		}
+		return decision
 	}
-	if collector != nil {
-		collector.SetRetrieverSummary(retrieveResult.TraceSummary)
-		collector.AddRetrieverItems(retrieveResult.TraceItems)
+	if strings.TrimSpace(state.FallbackReply) != "" {
+		return knowledgeGuardDecision{FallbackReply: state.FallbackReply}
 	}
-	decision := buildKnowledgeGuardDecision(req.AIAgent, retrieveResult)
-	if len(decision.Instructions) > 0 {
-		*messages = append(*messages, decision.Instructions...)
+	if state.SkipGate {
+		return knowledgeGuardDecision{}
 	}
-	if strings.TrimSpace(retrieveResult.ContextText) != "" {
-		*messages = append(*messages, schema.SystemMessage(retrieveResult.ContextText))
-	}
-	return decision
+	*messages = append((*messages)[:0], state.Input.Messages...)
+	return state.Decision
 }

internal/ai/runtime/executor/service.go

@@ -13,14 +13,16 @@ import (
 )
 
 type Service struct {
-	agentFactory  *factory.AgentFactory
-	runnerFactory *factory.RunnerFactory
+	agentFactory      *factory.AgentFactory
+	runnerFactory     *factory.RunnerFactory
+	answerabilityGate *KnowledgeAnswerabilityGate
 }
 
 func NewService() *Service {
 	return &Service{
-		agentFactory:  factory.NewAgentFactory(),
-		runnerFactory: factory.NewRunnerFactory(),
+		agentFactory:      factory.NewAgentFactory(),
+		runnerFactory:     factory.NewRunnerFactory(),
+		answerabilityGate: NewKnowledgeAnswerabilityGate(),
 	}
 }
 
@@ -84,7 +86,7 @@ func (s *Service) ExecuteRun(ctx context.Context, req RunInput) (*RunResult, err
 		summary.TraceData = collector.Marshal()
 		return summary, fmt.Errorf("%s", summary.ErrorMessage)
 	}
-	messages := buildRunMessages(ctx, req, summary, collector)
+	messages := buildRunMessages(ctx, req, summary, collector, s.answerabilityGate)
 	if strings.TrimSpace(summary.ReplyText) != "" {
 		summary.Status = "completed"
 		summary.ModelName = req.AIConfig.ModelName