可观测性与指标监控

@RestController
public class ObservedChatController {

    private final ChatClient chatClient;
    private final MeterRegistry meterRegistry;

    public ObservedChatController(
            ChatClient chatClient,
            MeterRegistry meterRegistry) {
        this.chatClient = chatClient;
        this.meterRegistry = meterRegistry;
    }

    @GetMapping("/observed/chat")
    public String chat(@RequestParam String message) {
        // ChatClient 内部自动生成 Span，无需手动编码
        return chatClient.prompt()
                .user(message)
                .call()
                .content();
    }

    @GetMapping("/observed/stats")
    public Map<String, Object> stats() {
        Map<String, Object> result = new HashMap<>();
        
        // 查询 Token 用量
        meterRegistry.find("gen_ai.usage.total_tokens")
            .summary().ifPresent(s -> {
                result.put("totalTokens", s.totalAmount());
                result.put("avgTokens", s.mean());
            });
        
        // 查询调用延迟
        meterRegistry.find("gen_ai.client.operation.duration")
            .timer().ifPresent(t -> {
                result.put("avgDurationMs", t.mean(TimeUnit.MILLISECONDS));
                result.put("totalCalls", t.count());
            });
        
        return result;
    }
}

@Component
public class CategoryTaggingAdvisor implements RequestResponseAdvisor {

    private final MeterRegistry meterRegistry;

    public CategoryTaggingAdvisor(MeterRegistry meterRegistry) {
        this.meterRegistry = meterRegistry;
    }

    @Override
    public Prompt adviseRequest(Prompt prompt, 
            Map<String, Object> context) {
        String userContent = prompt.getInstructions().stream()
            .filter(m -> m.getMessageType() == MessageType.USER)
            .map(Message::getContent)
            .findFirst().orElse("");

        // 简单分类（实际可用 AI 做更精准的分类）
        String category = categorize(userContent);
        
        // 按类别计数
        Counter.builder("ai.chat.category")
            .tag("category", category)
            .register(meterRegistry)
            .increment();

        return prompt;
    }

    private String categorize(String text) {
        if (text.contains("课程") || text.contains("学分")) 
            return "course";
        if (text.contains("费用") || text.contains("学费")) 
            return "financial";
        return "general";
    }

    @Override
    public ChatResponse adviseResponse(ChatResponse response, 
            Map<String, Object> context) {
        return response;
    }

    @Override
    public String getName() { return "category-tagging"; }
}