// server/api/auth/login.post.ts
import { consola } from "consola";
import type { IUserLoginData, IUserLoginRequest } from "#shared/types";
import {
  clearNewApiAuthCookies,
  createErrorResponse,
  createSuccessResponse,
  createUpstreamErrorResponse,
  extractCookieMetaFromSetCookie,
  extractCookieValueFromSetCookie,
  newApiFetchRaw,
  setNewApiAuthCookies
} from "~~/server/utils";

interface INewApiWrappedLoginResponse {
  /** 登录成功时上游返回的用户信息 */
  data?: INewApiLoginUserData | null;
  /** 上游提示信息 */
  message?: string;
  /** 上游业务成功状态 */
  success?: boolean;
}

type NewApiLoginResponse = INewApiLoginUserData | INewApiWrappedLoginResponse;

interface INewApiLoginUserData extends IUserLoginData {
  /** NewAPI 登录结果如果返回额外字段，服务端会在返回前裁剪掉 */
  [key: string]: unknown;
}
/**
 * 允许从请求体透传给上游的字段列表。
 * 只有在这里声明过的字段才会被转发，其余字段一律丢弃，防止参数污染。
 */
const LOGIN_FIELDS = ["username", "password"] as const satisfies ReadonlyArray<
  keyof IUserLoginRequest
>;

/**
 * POST /api/auth/login
 */
export default defineEventHandler(async (event) => {
  const requestBody = await readBody<Partial<IUserLoginRequest> | null>(event);

  // 只接受 JSON 对象或 null，避免数组/字符串等无效 body 被透传到上游。
  if (requestBody !== null && typeof requestBody !== "object") {
    clearNewApiAuthCookies(event);
    return createErrorResponse(400, "请求体必须是 JSON 对象");
  }

  const payload: IUserLoginRequest = {};
  for (const field of LOGIN_FIELDS) {
    const value = requestBody?.[field];
    if (typeof value === "string") {
      payload[field] = value;
    }
  }

  try {
    // 登录必须读取上游 Set-Cookie，因此这里使用 raw fetch 保留响应头。
    const result = await newApiFetchRaw<NewApiLoginResponse>(
      "/api/user/login",
      {
        method: "POST",
        body: payload,
        headers: {
          "Content-Type": "application/json"
        }
      }
    );

    const normalized = normalizeLoginResponse(result._data);
    if (!normalized.user) {
      // 上游业务失败时同步清理本地旧登录态，避免继续携带坏 cookie。
      clearNewApiAuthCookies(event);
      return createErrorResponse(1, normalized.message, result._data ?? null);
    }

    const session = extractCookieValueFromSetCookie(result.headers, "session");
    if (!session) {
      // 没有 session 就不能恢复 NewAPI 登录态，必须让前端明确感知失败。
      clearNewApiAuthCookies(event);
      consola.error(
        "/api/auth/login 登录成功但未收到 NewAPI session，请稍后重试"
      );
      return createErrorResponse(500, "服务器错误，请稍后重试");
    }

    setNewApiAuthCookies(
      event,
      session,
      normalized.user.id,
      extractCookieMetaFromSetCookie(result.headers, "session")
    );

    return createSuccessResponse<IUserLoginData>(
      normalized.user,
      normalized.message
    );
  } catch (error) {
    clearNewApiAuthCookies(event);
    consola.error("/api/auth/login 登录失败", error);
    return createUpstreamErrorResponse(error, "登录失败");
  }
});

/** 兼容上游直接返回用户对象和 { success, message, data } 包装结构 */
const normalizeLoginResponse = (
  response: NewApiLoginResponse | undefined
): { message: string; user: IUserLoginData | null } => {
  if (isUser(response)) {
    return {
      message: "登录成功",
      user: pickUserBasicData(response)
    };
  }

  if (!isRecord(response)) {
    consola.error("/api/auth/login 登录失败：响应不是对象");
    return {
      message: "登录失败",
      user: null
    };
  }

  const wrapped = response as INewApiWrappedLoginResponse;
  const message =
    wrapped.message || (wrapped.success ? "登录成功" : "登录失败");

  if (wrapped.success !== true || !isUser(wrapped.data)) {
    consola.error("/api/auth/login 登录失败：上游返回的数据格式不正确");
    return {
      message,
      user: null
    };
  }

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

/** 只返回前端需要的基础用户字段，避免上游额外字段透出 */
const pickUserBasicData = (user: INewApiLoginUserData): IUserLoginData => {
  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 INewApiLoginUserData => {
  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";
};