package com.wecom.robot.service.impl;

import com.wecom.robot.config.AiServiceConfig;
import com.wecom.robot.dto.ai.ChatRequest;
import com.wecom.robot.dto.ai.ChatResponse;
import com.wecom.robot.service.AiServiceClient;
import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker;
import io.github.resilience4j.timelimiter.annotation.TimeLimiter;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import java.util.concurrent.CompletableFuture;

@Slf4j
@Service
@RequiredArgsConstructor
public class AiServiceClientImpl implements AiServiceClient {

    private static final String CHAT_ENDPOINT = "/ai/chat";
    private static final String HEALTH_ENDPOINT = "/ai/health";

    private final AiServiceConfig aiServiceConfig;
    private final RestTemplate restTemplate;

    @Override
    @CircuitBreaker(name = "aiService", fallbackMethod = "generateReplyFallback")
    @TimeLimiter(name = "aiService")
    public CompletableFuture<ChatResponse> generateReply(ChatRequest request) {
        log.info("[AC-MCA-04] 调用 AI 服务: sessionId={}", request.getSessionId());

        String url = aiServiceConfig.getUrl() + CHAT_ENDPOINT;
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<ChatRequest> entity = new HttpEntity<>(request, headers);

        ResponseEntity<ChatResponse> response = restTemplate.postForEntity(
                url, entity, ChatResponse.class);

        log.info("[AC-MCA-05] AI 服务响应: sessionId={}, shouldTransfer={}",
                request.getSessionId(),
                response.getBody() != null ? response.getBody().getShouldTransfer() : null);

        return CompletableFuture.completedFuture(response.getBody());
    }

    public CompletableFuture<ChatResponse> generateReplyFallback(ChatRequest request, Throwable cause) {
        log.warn("[AC-MCA-06][AC-MCA-07] AI 服务降级: sessionId={}, cause={}",
                request.getSessionId(), cause.getMessage());

        ChatResponse fallbackResponse = ChatResponse.fallbackWithTransfer(
                "抱歉，我暂时无法回答您的问题，正在为您转接人工客服...",
                cause.getMessage()
        );

        return CompletableFuture.completedFuture(fallbackResponse);
    }

    @Override
    public boolean healthCheck() {
        try {
            String url = aiServiceConfig.getUrl() + HEALTH_ENDPOINT;
            ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
            return response.getStatusCode().is2xxSuccessful();
        } catch (Exception e) {
            log.error("[AC-MCA-04] AI 服务健康检查失败: {}", e.getMessage());
            return false;
        }
    }
}