package com.zy.ai.service;

import com.zy.ai.entity.ChatCompletionRequest;
import com.zy.ai.entity.ChatCompletionResponse;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Mono;

import java.util.List;

@Slf4j
@Service
@RequiredArgsConstructor
public class LlmChatService {

    private final WebClient llmWebClient;

    @Value("${llm.api-key}")
    private String apiKey;

    @Value("${llm.model}")
    private String model;

    /**
     * 通用对话方法：传入 messages，返回大模型文本回复
     */
    public String chat(List<ChatCompletionRequest.Message> messages,
                       Double temperature,
                       Integer maxTokens) {

        ChatCompletionRequest req = new ChatCompletionRequest();
        req.setModel(model);
        req.setMessages(messages);
        req.setTemperature(temperature != null ? temperature : 0.3);
        req.setMax_tokens(maxTokens != null ? maxTokens : 1024);

        ChatCompletionResponse response = llmWebClient.post()
                .uri("/chat/completions")
                .header(HttpHeaders.AUTHORIZATION, "Bearer " + apiKey)
                .contentType(MediaType.APPLICATION_JSON)
                .bodyValue(req)   // 2.5.14 已支持 bodyValue
                .retrieve()
                .bodyToMono(ChatCompletionResponse.class)
                .doOnError(ex -> log.error("调用 LLM 失败", ex))
                .onErrorResume(ex -> Mono.empty())
                .block();

        if (response == null ||
                response.getChoices() == null ||
                response.getChoices().isEmpty() ||
                response.getChoices().get(0).getMessage() == null) {

            return "AI 诊断失败：未获取到有效回复。";
        }

        return response.getChoices().get(0).getMessage().getContent();
    }
}