graphbrainz/src/extensions/cover-art-archive/resolvers.js

import { resolveLookup } from '../../resolvers.js';

const SIZES = new Map([
  [null, null],
  [250, 250],
  [500, 500],
  ['FULL', null],
  ['SMALL', 250],
  ['LARGE', 500],
]);

function resolveImage(coverArt, args, { loaders }, info) {
  // Since migrating the schema to an extension, we lost custom enum values
  // for the time being. Translate any incoming `size` arg to the old enum
  // values.
  const size = SIZES.get(args.size);
  // Field should be `front` or `back`.
  const field = info.fieldName;
  if (coverArt.images) {
    const matches = coverArt.images.filter((image) => image[field]);
    if (!matches.length) {
      return null;
    } else if (matches.length === 1) {
      const match = matches[0];
      if (size === 250) {
        return match.thumbnails.small;
      } else if (size === 500) {
        return match.thumbnails.large;
      } else {
        return match.image;
      }
    }
  }
  const entityType = coverArt._entityType;
  const id = coverArt._id;
  const releaseID = coverArt._releaseID;
  if (entityType === 'release-group' && field === 'front') {
    // Release groups only have an endpoint to retrieve the front image.
    // If someone requests the back of a release group, return the back of the
    // release that the release group's cover art response points to.
    return loaders.coverArtArchiveURL.load(['release-group', id, field, size]);
  } else {
    return loaders.coverArtArchiveURL.load(['release', releaseID, field, size]);
  }
}

export default {
  CoverArtArchiveImage: {
    fileID: (image) => image.id,
  },
  CoverArtArchiveRelease: {
    front: resolveImage,
    back: resolveImage,
    images: (coverArt) => coverArt.images,
    artwork: (coverArt) => coverArt.images.length > 0,
    count: (coverArt) => coverArt.images.length,
    release: (coverArt, args, context, info) => {
      const mbid = coverArt._releaseID;
      if (mbid) {
        return resolveLookup(coverArt, { mbid }, context, info);
      }
      return null;
    },
  },
  Release: {
    coverArtArchive: (release, args, { loaders }) => {
      return loaders.coverArtArchive.load(['release', release.id]);
    },
  },
  ReleaseGroup: {
    coverArtArchive: (releaseGroup, args, { loaders }) => {
      return loaders.coverArtArchive.load(['release-group', releaseGroup.id]);
    },
  },
};