graphbrainz/lib/resolvers.js

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _promise = require('babel-runtime/core-js/promise');

var _promise2 = _interopRequireDefault(_promise);

var _keys = require('babel-runtime/core-js/object/keys');

var _keys2 = _interopRequireDefault(_keys);

exports.includeRelationships = includeRelationships;
exports.includeSubqueries = includeSubqueries;
exports.resolveLookup = resolveLookup;
exports.resolveBrowse = resolveBrowse;
exports.resolveSearch = resolveSearch;
exports.resolveRelationship = resolveRelationship;
exports.resolveLinked = resolveLinked;
exports.createSubqueryResolver = createSubqueryResolver;
exports.resolveDiscReleases = resolveDiscReleases;

var _helpers = require('./types/helpers');

var _graphqlRelay = require('graphql-relay');

var _util = require('./util');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function includeRelationships(params, info, fragments = info.fragments) {
  let fields = (0, _util.getFields)(info, fragments);
  if (info.fieldName !== 'relationships') {
    if (fields.relationships) {
      fields = (0, _util.getFields)(fields.relationships, fragments);
    } else {
      if (fields.edges) {
        fields = (0, _util.getFields)(fields.edges, fragments);
        if (fields.node) {
          return includeRelationships(params, fields.node, fragments);
        }
      }
      return params;
    }
  }
  if (fields) {
    const relationships = (0, _keys2.default)(fields);
    const includeRels = relationships.map(field => {
      return `${(0, _helpers.toDashed)((0, _helpers.toSingular)(field))}-rels`;
    });
    if (includeRels.length) {
      params = {
        ...params,
        inc: (0, _util.extendIncludes)(params.inc, includeRels)
      };
    }
  }
  return params;
}

function includeSubqueries(params, info, fragments = info.fragments) {
  const subqueryIncludes = {
    aliases: ['aliases'],
    artistCredit: ['artist-credits'],
    artistCredits: ['artist-credits'],
    isrcs: ['isrcs'],
    media: ['media', 'discids'],
    rating: ['ratings'],
    tags: ['tags']
  };
  let fields = (0, _util.getFields)(info, fragments);
  const include = [];
  for (const key in subqueryIncludes) {
    if (fields[key]) {
      const value = subqueryIncludes[key];
      include.push(...value);
    }
  }
  params = {
    ...params,
    inc: (0, _util.extendIncludes)(params.inc, include)
  };
  if (fields.edges) {
    fields = (0, _util.getFields)(fields.edges, fragments);
    if (fields.node) {
      params = includeSubqueries(params, fields.node, fragments);
    }
  }
  return params;
}

function resolveLookup(root, { mbid, ...params }, { loaders }, info) {
  if (!mbid && !params.resource) {
    throw new Error('Lookups by a field other than MBID must provide: resource');
  }
  const entityType = (0, _helpers.toDashed)(info.fieldName);
  params = includeSubqueries(params, info);
  params = includeRelationships(params, info);
  return loaders.lookup.load([entityType, mbid, params]);
}

function resolveBrowse(root, { first, after, type = [], status = [], discID, isrc, iswc, ...args }, { loaders }, info) {
  const pluralName = (0, _helpers.toDashed)(info.fieldName);
  const singularName = (0, _helpers.toSingular)(pluralName);
  let params = {
    ...args,
    type,
    status,
    limit: first,
    offset: (0, _graphqlRelay.getOffsetWithDefault)(after, -1) + 1 || undefined
  };
  params = includeSubqueries(params, info);
  params = includeRelationships(params, info, info.fragments);
  const formatParam = value => value.toLowerCase().replace(/ /g, '');
  params.type = params.type.map(formatParam);
  params.status = params.status.map(formatParam);
  let request;
  if (discID) {
    request = loaders.lookup.load(['discid', discID, params]);
    // If fetching releases by disc ID, they will already include the `media`
    // and `discids` subqueries, and it is invalid to specify them.
    if (params.inc) {
      params.inc = params.inc.filter(value => {
        return value !== 'media' && value !== 'discids';
      });
    }
  } else if (isrc) {
    request = loaders.lookup.load(['isrc', isrc, params]);
  } else if (iswc) {
    request = loaders.lookup.load(['iswc', iswc, params]);
  } else {
    request = loaders.browse.load([singularName, params]);
  }
  return request.then(list => {
    // Grab the list, offet, and count from the response and use them to build
    // a Relay connection object.
    const {
      [pluralName]: arraySlice,
      [`${singularName}-offset`]: sliceStart = 0,
      [`${singularName}-count`]: arrayLength = arraySlice.length
    } = list;
    const meta = { sliceStart, arrayLength };
    const connection = (0, _graphqlRelay.connectionFromArraySlice)(arraySlice, { first, after }, meta);
    return {
      nodes: connection.edges.map(edge => edge.node),
      totalCount: arrayLength,
      ...connection
    };
  });
}

function resolveSearch(root, { after, first, query, ...args }, { loaders }, info) {
  const pluralName = (0, _helpers.toDashed)(info.fieldName);
  const singularName = (0, _helpers.toSingular)(pluralName);
  let params = {
    ...args,
    limit: first,
    offset: (0, _graphqlRelay.getOffsetWithDefault)(after, -1) + 1 || undefined
  };
  params = includeSubqueries(params, info);
  return loaders.search.load([singularName, query, params]).then(list => {
    const {
      [pluralName]: arraySlice,
      offset: sliceStart,
      count: arrayLength
    } = list;
    const meta = { sliceStart, arrayLength };
    const connection = (0, _graphqlRelay.connectionFromArraySlice)(arraySlice, { first, after }, meta);
    // Move the `score` field up to the edge object and make sure it's a
    // number (MusicBrainz returns a string).
    const edges = connection.edges.map(edge => ({
      ...edge,
      score: +edge.node.score
    }));
    const connectionWithExtras = {
      nodes: edges.map(edge => edge.node),
      totalCount: arrayLength,
      ...connection,
      edges
    };
    return connectionWithExtras;
  });
}

function resolveRelationship(rels, args, context, info) {
  const targetType = (0, _helpers.toDashed)((0, _helpers.toSingular)(info.fieldName)).replace('-', '_');
  let matches = rels.filter(rel => rel['target-type'] === targetType);
  // There's no way to filter these at the API level, so do it here.
  if (args.direction != null) {
    matches = matches.filter(rel => rel.direction === args.direction);
  }
  if (args.type != null) {
    matches = matches.filter(rel => rel.type === args.type);
  }
  if (args.typeID != null) {
    matches = matches.filter(rel => rel['type-id'] === args.typeID);
  }
  const connection = (0, _graphqlRelay.connectionFromArray)(matches, args);
  return {
    nodes: connection.edges.map(edge => edge.node),
    totalCount: matches.length,
    ...connection
  };
}

function resolveLinked(entity, args, context, info) {
  const parentEntity = (0, _helpers.toDashed)(info.parentType.name);
  args = { ...args, [parentEntity]: entity.id };
  return resolveBrowse(entity, args, context, info);
}

/**
 * If we weren't smart enough or weren't able to include the `inc` parameter
 * for a particular field that's being requested, make another request to grab
 * it (after making sure it isn't already available).
 */
function createSubqueryResolver({ inc, key } = {}, handler = value => value) {
  return (entity, args, { loaders }, info) => {
    key = key || (0, _helpers.toDashed)(info.fieldName);
    let promise;
    if (key in entity) {
      promise = _promise2.default.resolve(entity);
    } else {
      const { _type: entityType, id } = entity;
      const params = { inc: [inc || key] };
      promise = loaders.lookup.load([entityType, id, params]);
    }
    return promise.then(entity => handler(entity[key], args));
  };
}

function resolveDiscReleases(disc, args, context, info) {
  const { releases } = disc;
  if (releases != null) {
    const connection = (0, _graphqlRelay.connectionFromArray)(releases, args);
    return {
      nodes: connection.edges.map(edge => edge.node),
      totalCount: releases.length,
      ...connection
    };
  }
  args = { ...args, discID: disc.id };
  return resolveBrowse(disc, args, context, info);
}