// server/utils/runtimeState.ts - 服务启动时间内存状态 + 问答记录 DB 读写
import { prisma } from "~~/server/utils/db";
import { serverEnv } from "~~/server/utils/env";

/** 进程启动时间，用于 `/api/stats` 返回 uptime */
const startTime = Date.now();

/** 对外展示的服务版本，和 README/API 文档保持一致 */
export const SERVICE_VERSION = "1.1.0";

/** 格式化成本地 `YYYY-MM-DD HH:mm:ss`，对齐旧 Python 服务记录格式 */
export const formatLocalDateTime = (date: Date) => {
  const pad = (value: number) => value.toString().padStart(2, "0");

  return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(
    date.getDate()
  )} ${pad(date.getHours())}:${pad(date.getMinutes())}:${pad(
    date.getSeconds()
  )}`;
};

/**
 * 向数据库写入一条问答记录
 */
export const addQaRecord = async (record: {
  userId: string;
  question: string;
  type: string;
  options: string;
  answer: string;
  hash: string;
}) => {
  await prisma.qaRecord.create({
    data: {
      userId: record.userId,
      question: record.question,
      type: record.type,
      options: record.options || null,
      answer: record.answer || null,
      hash: record.hash
    }
  });
};

/**
 * 按用户 + hash 查找 DB 缓存答案
 *
 * 只返回 cacheClearedAt 之后写入的记录；未存入时间或 hash 为 null 的老记录不会命中
 */
export const lookupCachedAnswer = async (
  userId: string,
  hash: string,
  cacheClearedAt: Date | null
): Promise<string | null> => {
  const record = await prisma.qaRecord.findFirst({
    where: {
      userId,
      hash,
      ...(cacheClearedAt ? { createdAt: { gt: cacheClearedAt } } : {})
    },
    orderBy: { createdAt: "desc" },
    select: { answer: true }
  });
  return record?.answer ?? null;
};

/**
 * 从数据库分页读取指定用户的问答记录，按创建时间倒序
 */
export const getQaRecords = async (
  userId: string,
  options: { page: number; size: number }
) => {
  const { page, size } = options;
  const skip = (page - 1) * size;
  const [total, rows] = await Promise.all([
    prisma.qaRecord.count({ where: { userId } }),
    prisma.qaRecord.findMany({
      where: { userId },
      orderBy: { createdAt: "desc" },
      skip,
      take: size,
      select: {
        question: true,
        type: true,
        options: true,
        answer: true,
        createdAt: true
      }
    })
  ]);
  const records = rows.map((r) => ({
    time: formatLocalDateTime(r.createdAt),
    timestamp: r.createdAt.toISOString(),
    question: r.question,
    type: r.type,
    options: r.options ?? "",
    answer: r.answer ?? ""
  }));
  return { records, total };
};
/** 生成 `/api/stats` 的基础运行时信息，不包含用户相关数据 */
export const getRuntimeStats = () => {
  return {
    version: SERVICE_VERSION,
    uptime: (Date.now() - startTime) / 1000,
    model: serverEnv.openAiModel
  };
};