import { PrismaClient } from "@prisma/client";
import kvStore from "./kvStore.js";

const prisma = new PrismaClient();

// 系统保留UUID用于存储站点信息
const SYSTEM_DEVICE_UUID = "00000000-0000-4000-8000-000000000000";

// 存储 readme 值的内存变量
let readmeValue = null;
let systemDeviceId = null;

// 封装默认 readme 对象
const defaultReadme = {
  title: "Classworks 服务端",
  readme: "暂无 Readme 内容",
};

/**
 * 获取或创建系统设备
 * @returns {Promise<number>} 系统设备ID
 */
async function getSystemDeviceId() {
  if (systemDeviceId) return systemDeviceId;

  let device = await prisma.device.findUnique({
    where: { uuid: SYSTEM_DEVICE_UUID },
    select: { id: true },
  });

  if (!device) {
    device = await prisma.device.create({
      data: {
        uuid: SYSTEM_DEVICE_UUID,
        name: "系统设备",
      },
      select: { id: true },
    });
  }

  systemDeviceId = device.id;
  return systemDeviceId;
}

/**
 * 初始化 readme 值
 * 在应用启动时调用此函数
 */
export const initReadme = async () => {
  try {
    const deviceId = await getSystemDeviceId();
    const storedValue = await kvStore.get(deviceId, "info");

    // 合并默认值与存储值，确保结构完整
    readmeValue = {
      ...defaultReadme,
      ...(storedValue || {}),
    };

    console.log("✅ 站点信息初始化成功");
  } catch (error) {
    console.error("❌ 站点信息初始化失败:", {
      message: error?.message,
      stack: error?.stack,
    });

    // 确保在异常情况下也有默认值
    readmeValue = { ...defaultReadme };
  }
};

/**
 * 获取当前的 readme 值
 * @returns {Object} readme 值对象
 */
export const getReadmeValue = () => {
  return readmeValue || { ...defaultReadme };
};

/**
 * 更新 readme 值
 * @param {Object} newValue - 新的 readme 值
 * @returns {Promise<void>}
 */
export const updateReadmeValue = async (newValue) => {
  try {
    const deviceId = await getSystemDeviceId();
    await kvStore.upsert(deviceId, "info", newValue);
    readmeValue = {
      ...defaultReadme,
      ...newValue,
    };
    console.log("✅ 站点信息更新成功");
  } catch (error) {
    console.error("❌ 站点信息更新失败:", {
      message: error?.message,
      stack: error?.stack,
    });
    throw error;
  }
};