graphql-compose-mongoose/node8/prepareConnectionResolver.js

Plugin for `graphql-compose` which derive a graphql types from a mongoose model.

'use strict';

exports.__esModule = true;

var _extends2 = require('babel-runtime/helpers/extends');

var _extends3 = _interopRequireDefault(_extends2);

exports.prepareConnectionResolver = prepareConnectionResolver;
exports.prepareCursorQuery = prepareCursorQuery;

var _getIndexesFromModel = require('./utils/getIndexesFromModel');

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

/* eslint-disable no-use-before-define, no-param-reassign, global-require */

function prepareConnectionResolver(model, tc, opts) {
  try {
    require.resolve('graphql-compose-connection');
  } catch (e) {
    return;
  }
  const composeWithConnection = require('graphql-compose-connection').default;

  const uniqueIndexes = (0, _getIndexesFromModel.extendByReversedIndexes)((0, _getIndexesFromModel.getUniqueIndexes)(model), {
    reversedFirst: true
  });
  const sortConfigs = {};
  uniqueIndexes.forEach(indexData => {
    const keys = Object.keys(indexData);
    let name = keys.join('__').toUpperCase().replace(/[^_a-zA-Z0-9]/i, '__');
    if (indexData[keys[0]] === 1) {
      name = `${name}_ASC`;
    } else if (indexData[keys[0]] === -1) {
      name = `${name}_DESC`;
    }
    sortConfigs[name] = {
      value: indexData,
      cursorFields: keys,
      beforeCursorQuery: (rawQuery, cursorData) => {
        prepareCursorQuery(rawQuery, cursorData, keys, indexData, '$lt', '$gt');
      },
      afterCursorQuery: (rawQuery, cursorData) => {
        prepareCursorQuery(rawQuery, cursorData, keys, indexData, '$gt', '$lt');
      }
    };
  });

  composeWithConnection(tc, {
    findResolverName: 'findMany',
    countResolverName: 'count',
    sort: (0, _extends3.default)({}, sortConfigs, opts)
  });
}

function prepareCursorQuery(rawQuery, cursorData, indexKeys, indexData, nextOper, prevOper) {
  if (indexKeys.length === 1) {
    // When single index { a: 1 }, then just add to one criteria to the query:
    // rawQuery.a = { $gt|$lt: cursorValue } - for next|prev record
    const k = indexKeys[0];
    if (!rawQuery[k]) rawQuery[k] = {};
    if (indexData[k] === 1) {
      rawQuery[k][nextOper] = cursorData[k];
    } else {
      rawQuery[k][prevOper] = cursorData[k];
    }
  } else {
    // When compound index {a: 1, b: -1, c: 1 } then we should add OR criterias to the query:
    // rawQuery.$or = [
    //   { a: cursorValueA, b: cursorValueB, c: { $gt|$lt: cursorValueC } },
    //   { a: cursorValueA, b: { $gt|$lt: cursorValueB } },
    //   { a: { $gt|$lt: cursorValueA } },
    // ]
    const orCriteries = [];
    for (let i = indexKeys.length - 1; i >= 0; i--) {
      const criteria = {};
      indexKeys.forEach((k, ii) => {
        if (ii < i) {
          criteria[k] = cursorData[k];
        } else if (ii === i) {
          if (indexData[k] === 1) {
            criteria[k] = { [nextOper]: cursorData[k] };
          } else {
            criteria[k] = { [prevOper]: cursorData[k] };
          }
        }
      });
      orCriteries.push(criteria);
    }
    rawQuery.$or = orCriteries;
  }
}