CentralPing/mongoose-plugin-modified

'use strict';

const _ = require('lodash');

/**
 * @module mongoose-plugin-modified
 * @example
```js
var modifiedPlugin = require('mongoose-plugin-modified');
var schema = Schema({...});
schema.plugin(modifiedPlugin[, OPTIONS]);
```
*/

module.exports = lastModifiedPlugin;

function lastModifiedPlugin(schema, options) {
  /**
   * @param {object} [options]
   * @param {string} options.optionKey=modified - the path options key to mark paths for inclusion in monitoring for modification. If no paths are tagged, document modification is monitored.
   * @param {object} [options.date] - options for configuring the path for storing the date.
   * @param {string} options.date.path=modified.date - the path for storing the modified date.
   * @param {object} options.date.options - property options to set (`type` will always be `Date`). `(e.g. {select: false})`
   * @param {object} [options.by] - options for configuring the path for storing the modifier.
   * @param {string} options.by.path=modified.by - the path for storing the document modifier.
   * @param {string} options.by.ref - the reference model to use `(e.g. {by: {ref: 'ModelRefName'}})`
   * @param {object} options.by.options - property options to set (if not a reference the `type` will always be `String`). `(e.g. {select: false})`
  */
  options = _.merge({
    optionKey: 'modified',
    date: {
      path: 'modified.date',
      options: {}
    },
    by: {
      path: 'modified.by',
      ref: undefined,
      options: {
        set: function markModifiedBy(v) {
          this.markModified(options.by.path);
          return v;
        }
      }
    }
  }, options);

  const paths = Object.keys(schema.paths).filter(function (path) {
    const schemaType = schema.path(path);

    return _.get(schemaType, `options.${options.optionKey}`);
  });

  // If no fields are flagged with the optionKey, monitor all fields
  if (paths.length === 0) { paths.push(undefined); }

  schema.path(options.date.path, _.defaults({
    type: Date
  }, options.date.options));

  if (options.by.path) {
    if (options.by.options.required === true) {
      options.by.options.required = function requiredCheck(val) {
        // Return true only if not a new document and val is undefined
        return this.isNew ? false : this.isModified(options.date.path) ? val === undefined : false;
      };

      options.by.options.validate = {
        validator: function validateModifiedBy(val) {
          return this.isNew ? true : (this.isModified(options.date.path) ? this.isModified(options.by.path) : true);
        },
        msg: '{PATH} must be updated for document modification'
      };
    }

    schema.path(options.by.path, _.defaults(
      options.by.ref ?
        {type: schema.constructor.Types.ObjectId, ref: options.by.ref} :
        {type: String},
      options.by.options
    ));
  }

  schema.pre('validate', function lastModifiedSave(next) {
    // check if at least one indicated field has been modified
    if (!this.isNew && paths.some(this.isModified, this)) {
      this.set(options.date.path, Date.now());
    }

    next();
  });
}