text: 'use strict';
  
  const ArrayMethods = require('../../array/methods');
  const Document = require('../../../document');
  const castObjectId = require('../../../cast/objectid');
  const getDiscriminatorByValue = require('../../../helpers/discriminator/getDiscriminatorByValue');
  const internalToObjectOptions = require('../../../options').internalToObjectOptions;
  const utils = require('../../../utils');
  const isBsonType = require('../../../helpers/isBsonType');
  
  const arrayParentSymbol = require('../../../helpers/symbols').arrayParentSymbol;
  const arrayPathSymbol = require('../../../helpers/symbols').arrayPathSymbol;
  const arraySchemaSymbol = require('../../../helpers/symbols').arraySchemaSymbol;
  const documentArrayParent = require('../../../helpers/symbols').documentArrayParent;
  
  const methods = {
    /*!
     * ignore
     */
  
    toBSON() {
      return this.toObject(internalToObjectOptions);
    },
  
    /*!
     * ignore
     */
  
    getArrayParent() {
      return this[arrayParentSymbol];
    },
  
    /**
     * Overrides MongooseArray#cast
     *
     * @method _cast
     * @api private
     * @receiver MongooseDocumentArray
     */
  
    _cast(value, index) {
      if (this[arraySchemaSymbol] == null) {
        return value;
      }
      let Constructor = this[arraySchemaSymbol].casterConstructor;
      const isInstance = Constructor.$isMongooseDocumentArray ?
        utils.isMongooseDocumentArray(value) :
        value instanceof Constructor;
      if (isInstance ||
          // Hack re: #5001, see #5005
          (value && value.constructor && value.constructor.baseCasterConstructor === Constructor)) {
        if (!(value[documentArrayParent] && value.__parentArray)) {
          // value may have been created using array.create()
          value[documentArrayParent] = this[arrayParentSymbol];
          value.__parentArray = this;
        }
        value.$setIndex(index);
        return value;
      }
  
      if (value === undefined || value === null) {
        return null;
      }
  
      // handle cast('string') or cast(ObjectId) etc.
      // only objects are permitted so we can safely assume that
      // non-objects are to be interpreted as _id
      if (Buffer.isBuffer(value) ||
          isBsonType(value, 'ObjectID') || !utils.isObject(value)) {
        value = { _id: value };
      }
  
      if (value &&
          Constructor.discriminators &&
          Constructor.schema &&
          Constructor.schema.options &&
          Constructor.schema.options.discriminatorKey) {
        if (typeof value[Constructor.schema.options.discriminatorKey] === 'string' &&
            Constructor.discriminators[value[Constructor.schema.options.discriminatorKey]]) {
          Constructor = Constructor.discriminators[value[Constructor.schema.options.discriminatorKey]];
        } else {
          const constructorByValue = getDiscriminatorByValue(Constructor.discriminators, value[Constructor.schema.options.discriminatorKey]);
          if (constructorByValue) {
            Constructor = constructorByValue;
          }
        }
      }
  
      if (Constructor.$isMongooseDocumentArray) {
        return Constructor.cast(value, this, undefined, undefined, index);
      }
      const ret = new Constructor(value, this, undefined, undefined, index);
      ret.isNew = true;
      return ret;
    },
  
    /**
     * Searches array items for the first document with a matching _id.
     *
     * #### Example:
     *
     *     const embeddedDoc = m.array.id(some_id);
     *
     * @return {EmbeddedDocument|null} the subdocument or null if not found.
     * @param {ObjectId|String|Number|Buffer} id
     * @TODO cast to the _id based on schema for proper comparison
     * @method id
     * @api public
     * @memberOf MongooseDocumentArray
     */
  
    id(id) {
      let casted;
      let sid;
      let _id;
  
      try {
        casted = castObjectId(id).toString();
      } catch (e) {
        casted = null;
      }
  
      for (const val of this) {
        if (!val) {
          continue;
        }
  
        _id = val.get('_id');
  
        if (_id === null || typeof _id === 'undefined') {
          continue;
        } else if (_id instanceof Document) {
          sid || (sid = String(id));
          if (sid == _id._id) {
            return val;
          }
        } else if (!isBsonType(id, 'ObjectID') && !isBsonType(_id, 'ObjectID')) {
          if (id == _id || utils.deepEqual(id, _id)) {
            return val;
          }
        } else if (casted == _id) {
          return val;
        }
      }
  
      return null;
    },
  
    /**
     * Returns a native js Array of plain js objects
     *
     * #### Note:
     *
     * _Each sub-document is converted to a plain object by calling its `#toObject` method._
     *
     * @param {Object} [options] optional options to pass to each documents `toObject` method call during conversion
     * @return {Array}
     * @method toObject
     * @api public
     * @memberOf MongooseDocumentArray
     */
  
    toObject(options) {
      // `[].concat` coerces the return value into a vanilla JS array, rather
      // than a Mongoose array.
      return [].concat(this.map(function(doc) {
        if (doc == null) {
          return null;
        }
        if (typeof doc.toObject !== 'function') {
          return doc;
        }
        return doc.toObject(options);
      }));
    },
  
    $toObject() {
      return this.constructor.prototype.toObject.apply(this, arguments);
    },
  
    /**
     * Wraps [`Array#push`](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/push) with proper change tracking.
     *
     * @param {Object} [args...]
     * @api public
     * @method push
     * @memberOf MongooseDocumentArray
     */
  
    push() {
      const ret = ArrayMethods.push.apply(this, arguments);
  
      _updateParentPopulated(this);
  
      return ret;
    },
  
    /**
     * Pulls items from the array atomically.
     *
     * @param {Object} [args...]
     * @api public
     * @method pull
     * @memberOf MongooseDocumentArray
     */
  
    pull() {
      const ret = ArrayMethods.pull.apply(this, arguments);
  
      _updateParentPopulated(this);
  
      return ret;
    },
  
    /*!
     * Wraps [`Array#shift`](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/unshift) with proper change tracking.
     */
  
    shift() {
      const ret = ArrayMethods.shift.apply(this, arguments);
  
      _updateParentPopulated(this);
  
      return ret;
    },
  
    /*!
     * Wraps [`Array#splice`](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/splice) with proper change tracking and casting.
     */
  
    splice() {
      const ret = ArrayMethods.splice.apply(this, arguments);
  
      _updateParentPopulated(this);
  
      return ret;
    },
  
    /**
     * Helper for console.log
     *
     * @method inspect
     * @api public
     * @memberOf MongooseDocumentArray
     */
  
    inspect() {
      return this.toObject();
    },
  
    /**
     * Creates a subdocument casted to this schema.
     *
     * This is the same subdocument constructor used for casting.
     *
     * @param {Object} obj the value to cast to this arrays SubDocument schema
     * @method create
     * @api public
     * @memberOf MongooseDocumentArray
     */
  
    create(obj) {
      let Constructor = this[arraySchemaSymbol].casterConstructor;
      if (obj &&
          Constructor.discriminators &&
          Constructor.schema &&
          Constructor.schema.options &&
          Constructor.schema.options.discriminatorKey) {
        if (typeof obj[Constructor.schema.options.discriminatorKey] === 'string' &&
            Constructor.discriminators[obj[Constructor.schema.options.discriminatorKey]]) {
          Constructor = Constructor.discriminators[obj[Constructor.schema.options.discriminatorKey]];
        } else {
          const constructorByValue = getDiscriminatorByValue(Constructor.discriminators, obj[Constructor.schema.options.discriminatorKey]);
          if (constructorByValue) {
            Constructor = constructorByValue;
          }
        }
      }
  
      return new Constructor(obj, this);
    },
  
    /*!
     * ignore
     */
  
    notify(event) {
      const _this = this;
      return function notify(val, _arr) {
        _arr = _arr || _this;
        let i = _arr.length;
        while (i--) {
          if (_arr[i] == null) {
            continue;
          }
          switch (event) {
            // only swap for save event for now, we may change this to all event types later
            case 'save':
              val = _this[i];
              break;
            default:
              // NO-OP
              break;
          }
  
          if (utils.isMongooseArray(_arr[i])) {
            notify(val, _arr[i]);
          } else if (_arr[i]) {
            _arr[i].emit(event, val);
          }
        }
      };
    },
  
    set(i, val, skipModified) {
      const arr = this.__array;
      if (skipModified) {
        arr[i] = val;
        return this;
      }
      const value = methods._cast.call(this, val, i);
      methods._markModified.call(this, i);
      arr[i] = value;
      return this;
    },
  
    _markModified(elem, embeddedPath) {
      const parent = this[arrayParentSymbol];
      let dirtyPath;
  
      if (parent) {
        dirtyPath = this[arrayPathSymbol];
  
        if (arguments.length) {
          if (embeddedPath != null) {
            // an embedded doc bubbled up the change
            const index = elem.__index;
            dirtyPath = dirtyPath + '.' + index + '.' + embeddedPath;
          } else {
            // directly set an index
            dirtyPath = dirtyPath + '.' + elem;
          }
        }
  
        if (dirtyPath != null && dirtyPath.endsWith('.$')) {
          return this;
        }
  
        parent.markModified(dirtyPath, arguments.length !== 0 ? elem : parent);
      }
  
      return this;
    }
  };
  
  module.exports = methods;
  
  /*!
   * If this is a document array, each element may contain single
   * populated paths, so we need to modify the top-level document's
   * populated cache. See gh-8247, gh-8265.
   */
  
  function _updateParentPopulated(arr) {
    const parent = arr[arrayParentSymbol];
    if (!parent || parent.$__.populated == null) return;
  
    const populatedPaths = Object.keys(parent.$__.populated).
      filter(p => p.startsWith(arr[arrayPathSymbol] + '.'));
  
    for (const path of populatedPaths) {
      const remnant = path.slice((arr[arrayPathSymbol] + '.').length);
      if (!Array.isArray(parent.$__.populated[path].value)) {
        continue;
      }
  
      parent.$__.populated[path].value = arr.map(val => val.$populated(remnant));
    }
  }