alvis/gatsby-source-notion

/*
 *                            *** MIT LICENSE ***
 * -------------------------------------------------------------------------
 * This code may be modified and distributed under the MIT license.
 * See the LICENSE file for details.
 * -------------------------------------------------------------------------
 *
 * @summary   Collection of helpers for extracting metadata
 *
 * @author    Alvis HT Tang <alvis@hilbert.space>
 * @license   MIT
 * @copyright Copyright (c) 2021 - All Rights Reserved.
 * -------------------------------------------------------------------------
 */

import {
  getPropertyContentFromFile,
  getPropertyContentFromUser,
} from '#property';

import type {
  EntityWithUserDetail,
  Metadata,
  NotionAPIDatabase,
  NotionAPIPage,
  NotionAPIUser,
} from '#types';

/**
 * get common properties from a page or database, except for the title
 * @param entity the page or database object returned from Notion API
 * @returns common properties
 */
export function getMetadata<
  E extends EntityWithUserDetail<NotionAPIPage | NotionAPIDatabase>,
>(entity: E): Metadata {
  const { last_edited_time: lastEditedTime, url } = entity;
  const { created_time: createdTime } = entity;

  const variable = {
    url,
    ...getCommonPersonMetadata('lastEditedBy', entity.last_edited_by),
    lastEditedTime,
  };
  const invariant = {
    ...getCommonPersonMetadata('createdBy', entity.created_by),
    createdTime,
  };
  const visual = getCommonVisualMetadata(entity);

  return { ...variable, ...invariant, ...visual };
}

/**
 * get common visual properties from a page or database
 * @param prefix the prefix attached to the property name
 * @param user the user object returned from Notion API
 * @returns common properties
 */
export function getCommonPersonMetadata<P extends string>(
  prefix: P,
  user: NotionAPIUser | null,
): {
  [K in `${P}${'Avatar' | 'Email' | 'Name'}`]: string | null;
} {
  const properties = getPropertyContentFromUser(user);

  return {
    [`${prefix}Avatar`]: properties?.avatar ?? null,
    [`${prefix}Email`]: properties?.email ?? null,
    [`${prefix}Name`]: properties?.name ?? null,
  } as {
    [K in `${P}${'Avatar' | 'Email' | 'Name'}`]: string | null;
  };
}

/**
 * get common visual properties such as cover and icon from a page or database
 * @param entity the page or database object returned from Notion API
 * @returns common properties
 */
export function getCommonVisualMetadata<
  E extends EntityWithUserDetail<NotionAPIPage | NotionAPIDatabase>,
>(
  entity: E,
): {
  coverImage: string | null;
  iconEmoji: string | null;
  iconImage: string | null;
} {
  const { cover, icon } = entity;

  return {
    coverImage: cover ? getPropertyContentFromFile(cover) : null,
    iconEmoji: icon?.type === 'emoji' ? icon.emoji : null,
    iconImage:
      icon?.type === 'external' || icon?.type === 'file'
        ? getPropertyContentFromFile(icon)
        : null,
  };
}