text: 'use strict';
  
  const cleanPositionalOperators = require('../schema/cleanPositionalOperators');
  const get = require('../get');
  const getDiscriminatorByValue = require('../discriminator/getDiscriminatorByValue');
  const updatedPathsByArrayFilter = require('../update/updatedPathsByArrayFilter');
  
  /*!
   * Like `schema.path()`, except with a document, because impossible to
   * determine path type without knowing the embedded discriminator key.
   */
  
  module.exports = function getEmbeddedDiscriminatorPath(schema, update, filter, path, options) {
    const parts = path.split('.');
    let schematype = null;
    let type = 'adhocOrUndefined';
  
    filter = filter || {};
    update = update || {};
    const arrayFilters = options != null && Array.isArray(options.arrayFilters) ?
      options.arrayFilters : [];
    const updatedPathsByFilter = updatedPathsByArrayFilter(update);
  
    for (let i = 0; i < parts.length; ++i) {
      const subpath = cleanPositionalOperators(parts.slice(0, i + 1).join('.'));
      schematype = schema.path(subpath);
      if (schematype == null) {
        continue;
      }
  
      type = schema.pathType(subpath);
      if ((schematype.$isSingleNested || schematype.$isMongooseDocumentArrayElement) &&
          schematype.schema.discriminators != null) {
        const key = get(schematype, 'schema.options.discriminatorKey');
        const discriminatorValuePath = subpath + '.' + key;
        const discriminatorFilterPath =
          discriminatorValuePath.replace(/\.\d+\./, '.');
        let discriminatorKey = null;
  
        if (discriminatorValuePath in filter) {
          discriminatorKey = filter[discriminatorValuePath];
        }
        if (discriminatorFilterPath in filter) {
          discriminatorKey = filter[discriminatorFilterPath];
        }
  
        const wrapperPath = subpath.replace(/\.\d+$/, '');
        if (schematype.$isMongooseDocumentArrayElement &&
            get(filter[wrapperPath], '$elemMatch.' + key) != null) {
          discriminatorKey = filter[wrapperPath].$elemMatch[key];
        }
  
        if (discriminatorValuePath in update) {
          discriminatorKey = update[discriminatorValuePath];
        }
  
        for (const filterKey of Object.keys(updatedPathsByFilter)) {
          const schemaKey = updatedPathsByFilter[filterKey] + '.' + key;
          const arrayFilterKey = filterKey + '.' + key;
          if (schemaKey === discriminatorFilterPath) {
            const filter = arrayFilters.find(filter => filter.hasOwnProperty(arrayFilterKey));
            if (filter != null) {
              discriminatorKey = filter[arrayFilterKey];
            }
          }
        }
  
        if (discriminatorKey == null) {
          continue;
        }
  
        const discriminatorSchema = getDiscriminatorByValue(schematype.caster.discriminators, discriminatorKey).schema;
  
        const rest = parts.slice(i + 1).join('.');
        schematype = discriminatorSchema.path(rest);
        if (schematype != null) {
          type = discriminatorSchema._getPathType(rest);
          break;
        }
      }
    }
  
    return { type: type, schematype: schematype };
  };
  