import { WORKS_SQUARE_CONFIG } from '../api/works-config';
import { proxyAwareFetch } from '../utils/proxy-fetch';
import {
  getValidWorksSquareAccessToken,
  getWorksSquareAccountBinding,
  isCurrentWorksSquareAccountBinding,
  type WorksSquareAccountBinding,
} from '../services/works-square-session';
import type { TeacherAvailability, TeacherDefinition } from '../../shared/coding-teacher';

export class TeacherError extends Error {
  constructor(
    public status: number,
    public code: string,
    message: string
  ) {
    super(message);
  }
}
export interface TeacherAccount {
  id: string;
  binding: WorksSquareAccountBinding;
}
export function assertTeacherAccount(account: TeacherAccount) {
  if (!isCurrentWorksSquareAccountBinding(account.binding))
    throw new TeacherError(401, 'teacher_account_changed', '登录账号已变化，请重新打开老师。');
}
export async function teacherCloudRequest<T>(
  account: TeacherAccount,
  pathname: string
): Promise<T> {
  assertTeacherAccount(account);
  const token = await getValidWorksSquareAccessToken();
  assertTeacherAccount(account);
  if (!token) throw new TeacherError(401, 'teacher_auth_required', '请先登录。');
  const response = await proxyAwareFetch(
    WORKS_SQUARE_CONFIG.apiBaseUrl.replace(/\/+$/, '') + pathname,
    {
      headers: { Authorization: 'Bearer ' + token },
      signal: AbortSignal.timeout(30000),
    }
  );
  assertTeacherAccount(account);
  if (!response.ok) {
    const code =
      response.status === 403
        ? 'teacher_access_denied'
        : response.status === 409
          ? 'teacher_draft_changed'
          : 'teacher_config_unavailable';
    const message =
      response.status === 403
        ? '当前账号没有使用权限。'
        : response.status === 409
          ? '草稿已变化，请在运营页面重新打开试聊。'
          : '老师配置暂不可用，请稍后重试。';
    throw new TeacherError(response.status, code, message);
  }
  return (await response.json()) as T;
}
export async function currentTeacherAccount(): Promise<TeacherAccount> {
  const binding = getWorksSquareAccountBinding();
  if (!binding) throw new TeacherError(401, 'teacher_auth_required', '请先登录。');
  const provisional = { id: '', binding };
  const profile = await teacherCloudRequest<{ id: string }>(provisional, '/api/auth/me');
  if (!/^[0-9a-f]{8}(?:-[0-9a-f]{4}){3}-[0-9a-f]{12}$/i.test(profile.id))
    throw new TeacherError(502, 'teacher_account_unavailable', '无法确认当前账号。');
  return { id: profile.id, binding };
}
export const teacherAvailability = (account: TeacherAccount) =>
  teacherCloudRequest<TeacherAvailability>(account, '/api/coding-teacher/config');
export const teacherVersion = (account: TeacherAccount, version: number) =>
  teacherCloudRequest<{ version: number; payload: TeacherDefinition }>(
    account,
    '/api/coding-teacher/versions/' + version
  );
export const teacherPreview = (account: TeacherAccount, revision: number) =>
  teacherCloudRequest<{ draft_revision: number; payload: TeacherDefinition }>(
    account,
    '/api/admin/coding-teacher/preview?draft_revision=' + revision
  );