soldotno/aurora-core

/* eslint-disable no-underscore-dangle */
// Dependencies
import set from 'lodash.set';
import asyncEach from 'async-each';
import clone from 'stringify-clone';

// Utilities
import generateResolvers from './generate-resolvers';

/**
 * A method for actually resolving the data
 * needs of a config (server-side rendering).
 * Takes a config object to be resolved
 */
export default function resolveData(
  getModule = () => console.warn('No getModule() method supplied to constructor')
) {
  return function resolveData(
    settings = {},
    config = {}
  ) {
    /**
     * Clone the config to avoid mutation
     */
    const configCopy = clone(config);

    /**
     * Create an array of resolver specifications
     */
    const resolvers = generateResolvers('app', configCopy.app, ({
      path,
      module: {
        type = '',
        options = {},
      },
    }) => {
      return {
        path: `${path}.options._data`,
        getData: (() => {
          return getModule(type)
            .then(({ getData = () => Promise.resolve() }) => {
              return getData(Object.assign({}, { __settings: settings }, options._dataOptions));
            });
        }),
      };
    });

    /**
     * Return a Promise of the config
     * resolved with data by applying
     * the resolvers created above
     */
    return new Promise((resolve, reject) => {
      asyncEach(resolvers, ({
        path,
        getData = () => Promise.resolve(),
      }, cb) => {
        getData()
          .then((_data) => {
            set(configCopy, path, _data);
            cb();
          })
          .catch(cb);
      }, (err) => {
        return err ? reject(err) : resolve(configCopy);
      });
    });
  };
}