type Matrix = {

  baseUrl: string;

  token: string;

};

export async function main(

  matrix_res: Matrix,

  room_id: string,

  user_id: string,

  reason = "",

) {

  if (!matrix_res.token) {

    throw Error("Inviting a user requires an access token.");

  }

  const resp = await fetch(

    `${matrix_res.baseUrl}/_matrix/client/v3/rooms/${encodeURIComponent(

      room_id,

    )}/invite`,

    {

      method: "POST",

      headers: {

        Authorization: `Bearer ${matrix_res.token}`,

        "Content-Type": "application/json",

      },

      body: JSON.stringify({

        user_id,

        ...(reason && { reason }),

      }),

    },

  );

  if (!resp.ok) {

    throw Error(`Failed to invite: Error HTTP${resp.status}`);

  }

}