package com.vincent.rsf.server.ai.service.impl;

import com.vincent.rsf.framework.exception.CoolException;
import com.vincent.rsf.server.ai.config.AiDefaults;
import com.vincent.rsf.server.ai.dto.AiParamValidateResultDto;
import com.vincent.rsf.server.ai.entity.AiParam;
import io.micrometer.observation.ObservationRegistry;
import lombok.RequiredArgsConstructor;
import org.springframework.ai.chat.messages.UserMessage;
import org.springframework.ai.chat.model.ChatResponse;
import org.springframework.ai.chat.prompt.Prompt;
import org.springframework.ai.model.tool.DefaultToolCallingManager;
import org.springframework.ai.model.tool.ToolCallingManager;
import org.springframework.ai.openai.OpenAiChatModel;
import org.springframework.ai.openai.OpenAiChatOptions;
import org.springframework.ai.openai.api.OpenAiApi;
import org.springframework.ai.tool.execution.DefaultToolExecutionExceptionProcessor;
import org.springframework.ai.tool.resolution.SpringBeanToolCallbackResolver;
import org.springframework.ai.util.json.schema.SchemaType;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.client.RestClient;
import org.springframework.web.reactive.function.client.WebClient;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

@Component
@RequiredArgsConstructor
public class AiParamValidationSupport {

    private final GenericApplicationContext applicationContext;
    private final ObservationRegistry observationRegistry;

    /**
     * 对一份 AI 参数草稿做真实连通性校验。
     * 校验方式不是简单判断字段非空，而是直接构造聊天模型并发起一次最小探测调用，
     * 用返回结果和耗时生成前端可展示的校验报告。
     */
    public AiParamValidateResultDto validate(AiParam aiParam) {
        long startedAt = System.currentTimeMillis();
        try {
            OpenAiChatModel chatModel = createChatModel(aiParam);
            ChatResponse response = chatModel.call(new Prompt(List.of(new UserMessage("请回复 OK"))));
            if (response == null || response.getResult() == null || response.getResult().getOutput() == null
                    || !StringUtils.hasText(response.getResult().getOutput().getText())) {
                throw new CoolException("模型已连接，但未返回有效响应");
            }
            long elapsedMs = System.currentTimeMillis() - startedAt;
            return AiParamValidateResultDto.builder()
                    .status(AiDefaults.PARAM_VALIDATE_VALID)
                    .message("模型连通成功")
                    .model(aiParam.getModel())
                    .elapsedMs(elapsedMs)
                    .validatedAt(formatDate(new Date()))
                    .build();
        } catch (Exception e) {
            long elapsedMs = System.currentTimeMillis() - startedAt;
            String message = e instanceof CoolException ? e.getMessage() : "模型验证失败: " + e.getMessage();
            return AiParamValidateResultDto.builder()
                    .status(AiDefaults.PARAM_VALIDATE_INVALID)
                    .message(message)
                    .model(aiParam.getModel())
                    .elapsedMs(elapsedMs)
                    .validatedAt(formatDate(new Date()))
                    .build();
        }
    }

    private OpenAiChatModel createChatModel(AiParam aiParam) {
        /**
         * 构造仅用于校验的轻量聊天模型。
         * 这里沿用正式链路的 Observation 和 ToolCalling 依赖，
         * 保证校验结论与真实运行环境尽量一致。
         */
        OpenAiApi openAiApi = buildOpenAiApi(aiParam);
        ToolCallingManager toolCallingManager = DefaultToolCallingManager.builder()
                .observationRegistry(observationRegistry)
                .toolCallbackResolver(new SpringBeanToolCallbackResolver(applicationContext, SchemaType.OPEN_API_SCHEMA))
                .toolExecutionExceptionProcessor(new DefaultToolExecutionExceptionProcessor(false))
                .build();
        return new OpenAiChatModel(
                openAiApi,
                OpenAiChatOptions.builder()
                        .model(aiParam.getModel())
                        .temperature(aiParam.getTemperature())
                        .topP(aiParam.getTopP())
                        .maxTokens(aiParam.getMaxTokens())
                        .streamUsage(true)
                        .build(),
                toolCallingManager,
                org.springframework.retry.support.RetryTemplate.builder().maxAttempts(1).build(),
                observationRegistry
        );
    }

    private OpenAiApi buildOpenAiApi(AiParam aiParam) {
        /**
         * 根据表单里的 Base URL、API Key 和超时参数构造 OpenAI 兼容客户端。
         * 该方法被显式拆出来，是为了让“网络连接参数”和“模型选项”职责分离。
         */
        int timeoutMs = aiParam.getTimeoutMs() == null ? AiDefaults.DEFAULT_TIMEOUT_MS : aiParam.getTimeoutMs();
        SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
        requestFactory.setConnectTimeout(timeoutMs);
        requestFactory.setReadTimeout(timeoutMs);
        return OpenAiApi.builder()
                .baseUrl(aiParam.getBaseUrl())
                .apiKey(aiParam.getApiKey())
                .restClientBuilder(RestClient.builder().requestFactory(requestFactory))
                .webClientBuilder(WebClient.builder())
                .build();
    }

    private String formatDate(Date date) {
        /** 统一输出给前端的校验时间格式。 */
        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date);
    }
}