/**

 * @param fields *(optional)* A list of fields to return in the response.

 * Reference parameters of sub-objects with dot notation.

 *

 * @param exclude_fields *(optional)* A list of fields to exclude from the response.

 * Reference parameters of sub-objects with dot notation. If both `fields` and `exclude_fields`

 * are present, then only `exclude_fields` will be used.

 */

type Mailchimp = {

  api_key: string;

  server: string;

};

export async function main(

  auth: Mailchimp,

  campaign_id: string,

  fields?: string[],

  exclude_fields?: string[],

) {

  let url = `https://${auth.server}.api.mailchimp.com/3.0/campaigns/${campaign_id}?`;

  if (fields?.length) {

    url += `fields=${fields.join(",")}`;

  }

  if (exclude_fields?.length) {

    url += `${fields?.length ? "&" : ""}exclude_fields=${exclude_fields.join(

      ",",

    )}`;

  }

  const response = await fetch(url, {

    method: "GET",

    headers: {

      Authorization: `Bearer ${auth.api_key}`,

    },

  });

  if (!response.ok) {

    throw Error(await response.text());

  }

  return await response.json();

}