async function refreshAccessToken()

in apps/chat/src/utils/auth/auth-callbacks.ts [75:167]
72 lines of code
21 McCabe index (conditional complexity)

async function refreshAccessToken(token: Token) {
  const displayedTokenSub =
    process.env.SHOW_TOKEN_SUB === 'true' ? token.sub : '******';
  try {
    if (!token.providerId) {
      throw new Error(`No provider information exists in token`);
    }
    const client = NextClient.getClient(token.providerId);
    if (!client) {
      throw new Error(`No client for appropriate provider set`);
    }

    let msWaiting = 0;
    // eslint-disable-next-line no-constant-condition
    while (true) {
      const refresh = NextClient.getRefreshToken(token.userId);

      if (!refresh || !refresh.isRefreshing) {
        const localToken: RefreshToken = refresh || {
          isRefreshing: true,
          token,
        };
        if (
          typeof localToken.token?.accessTokenExpires === 'number' &&
          Date.now() < localToken.token.accessTokenExpires
        ) {
          return localToken.token;
        }

        NextClient.setIsRefreshTokenStart(token.userId, localToken);
        break;
      }

      await NextClient.delay();
      msWaiting += 50;

      if (msWaiting >= waitRefreshTokenTimeout * 1000) {
        throw new Error(
          `Waiting more than ${waitRefreshTokenTimeout} seconds for refreshing token`,
        );
      }
    }

    const refreshedTokens = await client.refresh(
      token.refreshToken as string | TokenSet,
    );

    if (
      !refreshedTokens ||
      (!refreshedTokens.expires_in && !refreshedTokens.expires_at)
    ) {
      throw new Error(`Error from auth provider while refreshing token`);
    }

    if (!refreshedTokens.refresh_token) {
      logger.warn(
        `Auth provider didn't provide new refresh token. Sub: ${displayedTokenSub}`,
      );
    }

    if (!refreshedTokens.refresh_token && !token.refreshToken) {
      throw new Error('No refresh tokens exists');
    }

    const returnToken = {
      ...token,
      user: getUser(refreshedTokens.access_token, token.providerId),
      access_token: refreshedTokens.access_token,
      accessTokenExpires: refreshedTokens.expires_in
        ? Date.now() + refreshedTokens.expires_in * 1000
        : (refreshedTokens.expires_at as number) * 1000,
      refreshToken: refreshedTokens.refresh_token ?? token.refreshToken, // Fall back to old refresh token
    };

    NextClient.setIsRefreshTokenStart(token.userId, {
      isRefreshing: false,
      token: returnToken,
    });
    return returnToken;
  } catch (error: unknown) {
    logger.error(
      error,
      `Error when refreshing token: ${
        (error as Error).message
      }. Sub: ${displayedTokenSub}`,
    );

    return {
      ...token,
      error: 'RefreshAccessTokenError',
    };
  }
}