import type { IUserMeData } from "#shared/types";
import {
  clearNewApiAuthCookies,
  createErrorResponse,
  createSuccessResponse,
  newApiAuthedFetch
} from "~~/server/utils";

interface INewApiWrappedUserResponse {
  /** 获取成功时上游返回的当前用户信息 */
  data?: INewApiSelfUserData | null;
  /** 上游提示信息，失败时优先返回给前端 */
  message?: string;
  /** 上游业务成功状态 */
  success?: boolean;
}

type NewApiUserResponse = INewApiSelfUserData | INewApiWrappedUserResponse;

interface INewApiSelfUserData extends IUserMeData {
  /** NewAPI /api/user/self 可能返回配额、设置、第三方绑定等额外字段 */
  [key: string]: unknown;
}

export default defineEventHandler(async (event) => {
  try {
    // 从本站 httpOnly cookie 读取登录态，并转发给 NewAPI 查询当前用户。
    const result = await newApiAuthedFetch<NewApiUserResponse>(
      event,
      "/api/user/self",
      {
        method: "GET"
      }
    );
    const normalized = normalizeUserResponse(result);

    if (!normalized.user) {
      // 上游业务失败代表当前 cookie 不再可靠，清理后返回统一 401。
      clearNewApiAuthCookies(event);
      return createErrorResponse(401, normalized.message);
    }

    return createSuccessResponse<IUserMeData>(
      normalized.user,
      normalized.message
    );
  } catch {
    // cookie 缺失或上游鉴权异常时统一视为未登录。
    clearNewApiAuthCookies(event);
    return createErrorResponse(401, "未登录");
  }
});

/** 兼容上游直接返回用户对象和 { success, message, data } 包装结构 */
const normalizeUserResponse = (
  response: NewApiUserResponse
): { message: string; user: IUserMeData | null } => {
  if (isUser(response)) {
    return {
      message: "获取用户信息成功",
      user: pickUserBasicData(response)
    };
  }

  if (!isRecord(response)) {
    return {
      message: "未登录",
      user: null
    };
  }

  const wrapped = response as INewApiWrappedUserResponse;
  const message =
    wrapped.message || (wrapped.success ? "获取用户信息成功" : "未登录");

  if (wrapped.success !== true || !isUser(wrapped.data)) {
    return {
      message,
      user: null
    };
  }

  return {
    message,
    user: pickUserBasicData(wrapped.data)
  };
};

/** 只返回前端需要的基础用户字段，避免泄露上游完整 self 信息 */
const pickUserBasicData = (user: INewApiSelfUserData): IUserMeData => {
  return {
    id: user.id,
    username: user.username,
    display_name: user.display_name,
    group: user.group,
    role: user.role,
    status: user.status
  };
};

const isUser = (value: unknown): value is INewApiSelfUserData => {
  return (
    isRecord(value) &&
    typeof value.id === "number" &&
    typeof value.username === "string" &&
    typeof value.display_name === "string" &&
    typeof value.group === "string" &&
    typeof value.role === "number" &&
    typeof value.status === "number"
  );
};

const isRecord = (value: unknown): value is Record<string, unknown> => {
  return value !== null && typeof value === "object";
};