Source: Mapper.js

import utils from './utils'
import Component from './Component'
import {
  belongsTo,
  belongsToType,
  hasMany,
  hasManyType,
  hasOne,
  hasOneType
} from './decorators'
import Record from './Record'
import Schema from './Schema'

const notify = function (...args) {
  const self = this
  const opts = args[args.length - 1]
  self.dbg(opts.op, ...args)
  if (opts.notify || (opts.notify === undefined && self.notify)) {
    setTimeout(() => {
      self.emit(opts.op, ...args)
    })
  }
}

const notify2 = function (...args) {
  const self = this
  const opts = args[args.length - 2]
  self.dbg(opts.op, ...args)
  if (opts.notify || (opts.notify === undefined && self.notify)) {
    setTimeout(() => {
      self.emit(opts.op, ...args)
    })
  }
}

const MAPPER_DEFAULTS = {
  /**
   * Whether to augment {@link Mapper#recordClass} with getter/setter property
   * accessors according to the properties defined in {@link Mapper#schema}.
   * This makes possible validation and change tracking on individual properties
   * when using the dot (e.g. `user.name = "Bob"`) operator to modify a
   * property.
   *
   * @name Mapper#applySchema
   * @type {boolean}
   * @default true
   */
  applySchema: true,

  /**
   * Whether to enable debug-level logs.
   *
   * @name Mapper#debug
   * @type {boolean}
   * @default false
   */
  debug: false,

  /**
   * The name of the registered adapter that this Mapper should used by default.
   *
   * @name Mapper#defaultAdapter
   * @type {string}
   * @default "http"
   */
  defaultAdapter: 'http',

  /**
   * The field used as the unique identifier on records handled by this Mapper.
   *
   * @name Mapper#idAttribute
   * @type {string}
   * @default id
   */
  idAttribute: 'id',

  lifecycleMethods: {
    count: {
      defaults: [{}, {}],
      skip: true,
      types: []
    },
    destroy: {
      defaults: [{}, {}],
      skip: true,
      types: []
    },
    destroyAll: {
      defaults: [{}, {}],
      skip: true,
      types: []
    },
    find: {
      defaults: [undefined, {}],
      types: []
    },
    findAll: {
      defaults: [{}, {}],
      types: []
    },
    sum: {
      defaults: [undefined, {}, {}],
      skip: true,
      types: []
    },
    update: {
      adapterArgs (mapper, id, props, opts) {
        return [id, mapper.toJSON(props, opts), opts]
      },
      beforeAssign: 1,
      defaults: [undefined, {}, {}],
      types: []
    },
    updateAll: {
      adapterArgs (mapper, props, query, opts) {
        return [mapper.toJSON(props, opts), query, opts]
      },
      beforeAssign: 0,
      defaults: [{}, {}, {}],
      types: []
    },
    updateMany: {
      adapterArgs (mapper, records, opts) {
        return [records.map(function (record) {
          return mapper.toJSON(record, opts)
        }), opts]
      },
      beforeAssign: 0,
      defaults: [[], {}],
      types: []
    }
  },

  /**
   * Minimum amount of meta information required to start operating against a
   * resource.
   *
   * @name Mapper#name
   * @type {string}
   */
  name: null,

  /**
   * Whether this Mapper should emit operational events.
   *
   * Defaults to `true` in the browser and `false` in Node.js
   *
   * @name Mapper#notify
   * @type {boolean}
   */
  notify: utils.isBrowser,

  /**
   * Whether {@link Mapper#create}, {@link Mapper#createMany}, {@link Mapper#save},
   * {@link Mapper#update}, {@link Mapper#updateAll}, {@link Mapper#updateMany},
   * {@link Mapper#find}, {@link Mapper#findAll}, {@link Mapper#destroy}, and
   * {@link Mapper#destroyAll} should return a raw result object that contains
   * both the instance data returned by the adapter _and_ metadata about the
   * operation.
   *
   * The default is to NOT return the result object, and instead return just the
   * instance data.
   *
   * @name Mapper#raw
   * @type {boolean}
   * @default false
   */
  raw: false,

  schema: null
}

/**
 * ```javascript
 * import {Mapper} from 'js-data'
 * ```
 *
 * The core of JSData's [ORM/ODM][orm] implementation. Given a minimum amout of
 * meta information about a resource, a Mapper can perform generic CRUD
 * operations against that resource. Apart from its configuration, a Mapper is
 * stateless. The particulars of various persistence layers has been abstracted
 * into adapters, which a Mapper uses to perform its operations.
 *
 * The term "Mapper" comes from the [Data Mapper Pattern][pattern] described in
 * Martin Fowler's [Patterns of Enterprise Application Architecture][book]. A
 * Data Mapper moves data between [in-memory object instances][record] and a
 * relational or document-based database. JSData's Mapper can work with any
 * persistence layer you can write an adapter for.
 *
 * utils._("Model" is a heavily overloaded term and is avoided in this documentation
 * to prevent confusion.)_
 *
 * [orm]: https://en.wikipedia.org/wiki/Object-relational_mapping
 * [pattern]: https://en.wikipedia.org/wiki/Data_mapper_pattern
 * [book]: http://martinfowler.com/books/eaa.html
 * [record]: Record.html
 *
 * @class Mapper
 * @extends Component
 * @param {Object} [opts] Configuration options.
 */
export default Component.extend({
  constructor: function Mapper (opts) {
    const self = this
    utils.classCallCheck(self, Mapper)
    Mapper.__super__.call(self)
    opts || (opts = {})

    /**
     * Hash of registered adapters. Don't modify. Use {@link Mapper#registerAdapter}.
     *
     * @name Mapper#_adapters
     * @private
     */
    Object.defineProperty(self, '_adapters', {
      value: undefined,
      writable: true
    })

    /**
     * Hash of registered listeners. Don't modify. Use {@link Mapper#on} and
     * {@link Mapper#off}.
     *
     * @name Mapper#_listeners
     * @private
     */
    Object.defineProperty(self, '_listeners', {
      value: {},
      writable: true
    })

    /**
     * Set the `false` to force the Mapper to work with POJO objects only.
     *
     * ```javascript
     * import {Mapper, Record} from 'js-data'
     * const UserMapper = new Mapper({ recordClass: false })
     * UserMapper.recordClass // false
     * const user = UserMapper#createRecord()
     * user instanceof Record // false
     * ```
     *
     * Set to a custom class to have records wrapped in your custom class.
     *
     * ```javascript
     * import {Mapper, Record} from 'js-data'
     *  // Custom class
     * class User {
     *   constructor (props = {}) {
     *     for (var key in props) {
     *       if (props.hasOwnProperty(key)) {
     *         this[key] = props[key]
     *       }
     *     }
     *   }
     * }
     * const UserMapper = new Mapper({ recordClass: User })
     * UserMapper.recordClass // function User() {}
     * const user = UserMapper#createRecord()
     * user instanceof Record // false
     * user instanceof User // true
     * ```
     *
     * Extend the {@link Record} class.
     *
     * ```javascript
     * import {Mapper, Record} from 'js-data'
     *  // Custom class
     * class User extends Record {
     *   constructor () {
     *     super(props)
     *   }
     * }
     * const UserMapper = new Mapper({ recordClass: User })
     * UserMapper.recordClass // function User() {}
     * const user = UserMapper#createRecord()
     * user instanceof Record // true
     * user instanceof User // true
     * ```
     *
     * @name Mapper#recordClass
     * @default {@link Record}
     */
    Object.defineProperty(self, 'recordClass', {
      value: undefined,
      writable: true
    })

    utils.fillIn(self, opts)
    utils.fillIn(self, utils.copy(MAPPER_DEFAULTS))

    if (!self.name) {
      throw new Error('mapper cannot function without a name!')
    }

    self._adapters || (self._adapters = {})

    if (!(self.schema instanceof Schema)) {
      self.schema = new Schema(self.schema || {})
    }

    if (utils.isUndefined(self.recordClass)) {
      self.recordClass = Record.extend()
    }

    if (self.recordClass) {
      self.recordClass.mapper = self

      // We can only apply the schema to the prototype of self.recordClass if the
      // class extends Record
      if (utils.getSuper(self.recordClass, true) === Record && self.schema && self.schema.apply && self.applySchema) {
        self.schema.apply(self.recordClass.prototype)
      }
    }
  },

  /**
   * Mapper lifecycle hook called by {@link Mapper#count}. If this method
   * returns a promise then {@link Mapper#count} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterCount
   * @method
   * @param {Object} query The `query` argument passed to {@link Mapper#count}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#count}.
   * @param {*} result The result, if any.
   */
  afterCount: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#create}. If this method
   * returns a promise then {@link Mapper#create} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterCreate
   * @method
   * @param {Object} props The `props` argument passed to {@link Mapper#create}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#create}.
   * @param {*} result The result, if any.
   */
  afterCreate: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#createMany}. If this method
   * returns a promise then {@link Mapper#createMany} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterCreateMany
   * @method
   * @param {Array} records The `records` argument passed to {@link Mapper#createMany}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#createMany}.
   * @param {*} result The result, if any.
   */
  afterCreateMany: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#destroy}. If this method
   * returns a promise then {@link Mapper#destroy} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterDestroy
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#destroy}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#destroy}.
   * @param {*} result The result, if any.
   */
  afterDestroy: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#destroyAll}. If this method
   * returns a promise then {@link Mapper#destroyAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterDestroyAll
   * @method
   * @param {*} data The `data` returned by the adapter.
   * @param {query} query The `query` argument passed to {@link Mapper#destroyAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#destroyAll}.
   * @param {*} result The result, if any.
   */
  afterDestroyAll: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#find}. If this method
   * returns a promise then {@link Mapper#find} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterFind
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#find}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#find}.
   * @param {*} result The result, if any.
   */
  afterFind: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#findAll}. If this method
   * returns a promise then {@link Mapper#findAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterFindAll
   * @method
   * @param {Object} query The `query` argument passed to {@link Mapper#findAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#findAll}.
   * @param {*} result The result, if any.
   */
  afterFindAll: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#sum}. If this method
   * returns a promise then {@link Mapper#sum} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterSum
   * @method
   * @param {Object} query The `query` argument passed to {@link Mapper#sum}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#sum}.
   * @param {*} result The result, if any.
   */
  afterSum: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#update}. If this method
   * returns a promise then {@link Mapper#update} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterUpdate
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#update}.
   * @param {props} props The `props` argument passed to {@link Mapper#update}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#update}.
   * @param {*} result The result, if any.
   */
  afterUpdate: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#updateAll}. If this method
   * returns a promise then {@link Mapper#updateAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterUpdateAll
   * @method
   * @param {Object} props The `props` argument passed to {@link Mapper#updateAll}.
   * @param {Object} query The `query` argument passed to {@link Mapper#updateAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#updateAll}.
   * @param {*} result The result, if any.
   */
  afterUpdateAll: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#updateMany}. If this method
   * returns a promise then {@link Mapper#updateMany} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#afterUpdateMany
   * @method
   * @param {Array} records The `records` argument passed to {@link Mapper#updateMany}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#updateMany}.
   * @param {*} result The result, if any.
   */
  afterUpdateMany: notify2,

  /**
   * Mapper lifecycle hook called by {@link Mapper#create}. If this method
   * returns a promise then {@link Mapper#create} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeCreate
   * @method
   * @param {Object} props The `props` argument passed to {@link Mapper#create}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#create}.
   */
  beforeCreate: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#createMany}. If this method
   * returns a promise then {@link Mapper#createMany} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeCreateMany
   * @method
   * @param {Array} records The `records` argument passed to {@link Mapper#createMany}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#createMany}.
   */
  beforeCreateMany: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#count}. If this method
   * returns a promise then {@link Mapper#count} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeCount
   * @method
   * @param {Object} query The `query` argument passed to {@link Mapper#count}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#count}.
   */
  beforeCount: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#destroy}. If this method
   * returns a promise then {@link Mapper#destroy} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeDestroy
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#destroy}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#destroy}.
   */
  beforeDestroy: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#destroyAll}. If this method
   * returns a promise then {@link Mapper#destroyAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeDestroyAll
   * @method
   * @param {query} query The `query` argument passed to {@link Mapper#destroyAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#destroyAll}.
   */
  beforeDestroyAll: notify,

  /**
   * Mappers lifecycle hook called by {@link Mapper#find}. If this method
   * returns a promise then {@link Mapper#find} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeFind
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#find}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#find}.
   */
  beforeFind: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#findAll}. If this method
   * returns a promise then {@link Mapper#findAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeFindAll
   * @method
   * @param {Object} query The `query` argument passed to {@link Mapper#findAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#findAll}.
   */
  beforeFindAll: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#sum}. If this method
   * returns a promise then {@link Mapper#sum} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeSum
   * @method
   * @param {string} field The `field` argument passed to {@link Mapper#sum}.
   * @param {Object} query The `query` argument passed to {@link Mapper#sum}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#sum}.
   */
  beforeSum: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#update}. If this method
   * returns a promise then {@link Mapper#update} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeUpdate
   * @method
   * @param {(string|number)} id The `id` argument passed to {@link Mapper#update}.
   * @param {props} props The `props` argument passed to {@link Mapper#update}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#update}.
   */
  beforeUpdate: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#updateAll}. If this method
   * returns a promise then {@link Mapper#updateAll} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeUpdateAll
   * @method
   * @param {Object} props The `props` argument passed to {@link Mapper#updateAll}.
   * @param {Object} query The `query` argument passed to {@link Mapper#updateAll}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#updateAll}.
   */
  beforeUpdateAll: notify,

  /**
   * Mapper lifecycle hook called by {@link Mapper#updateMany}. If this method
   * returns a promise then {@link Mapper#updateMany} will wait for the promise
   * to resolve before continuing.
   *
   * @name Mapper#beforeUpdateMany
   * @method
   * @param {Array} records The `records` argument passed to {@link Mapper#updateMany}.
   * @param {Object} opts The `opts` argument passed to {@link Mapper#updateMany}.
   */
  beforeUpdateMany: notify,

  /**
   * @name Mapper#_end
   * @method
   * @private
   */
  _end (result, opts, skip) {
    const self = this
    if (opts.raw) {
      utils._(opts, result)
    }
    if (skip) {
      return result
    }
    let _data = opts.raw ? result.data : result
    if (utils.isArray(_data) && _data.length && utils.isObject(_data[0])) {
      _data = _data.map(function (item) {
        return self.createRecord(item)
      })
    } else if (utils.isObject(_data)) {
      _data = self.createRecord(_data)
    }
    if (opts.raw) {
      result.data = _data
    } else {
      result = _data
    }
    return result
  },

  /**
   * Usage:
   *
   * Post.belongsTo(User, {
   *   localKey: 'myUserId'
   * })
   *
   * Comment.belongsTo(User)
   * Comment.belongsTo(Post, {
   *   localField: '_post'
   * })
   *
   * @name Mapper#belongsTo
   * @method
   */
  belongsTo (relatedMapper, opts) {
    return belongsTo(relatedMapper, opts)(this)
  },

  /**
   * Using the `query` argument, select records to pull from an adapter.
   * Expects back from the adapter the array of selected records.
   *
   * {@link Mapper#beforeCount} will be called before calling the adapter.
   * {@link Mapper#afterCount} will be called after calling the adapter.
   *
   * @name Mapper#count
   * @method
   * @param {Object} [query={}] Selection query.
   * @param {Object} [query.where] Filtering criteria.
   * @param {number} [query.skip] Number to skip.
   * @param {number} [query.limit] Number to limit to.
   * @param {Array} [query.orderBy] Sorting criteria.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * resulting data. If `true` return a response object that includes the
   * resulting data and metadata about the operation.
   * @return {Promise}
   */
  count (query, opts) {
    return this.crud('count', query, opts)
  },

  /**
   * Create and save a new the record using the provided `props`.
   *
   * {@link Mapper#beforeCreate} will be called before calling the adapter.
   * {@link Mapper#afterCreate} will be called after calling the adapter.
   *
   * @name Mapper#create
   * @method
   * @param {Object} props The properties for the new record.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * created data. If `true` return a response object that includes the created
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to create in a cascading
   * create if `props` contains nested relations. NOT performed in a
   * transaction. Each nested create will result in another {@link Mapper#create}
   * or {@link Mapper#createMany} call.
   * @param {string[]} [opts.pass=[]] Relations to send to the adapter as part
   * of the payload. Normally relations are not sent.
   * @return {Promise}
   */
  create (props, opts) {
    let op, adapter
    const self = this

    // Default values for arguments
    props || (props = {})
    opts || (opts = {})

    // Fill in "opts" with the Mapper's configuration
    utils._(self, opts)
    adapter = opts.adapter = self.getAdapterName(opts)

    // beforeCreate lifecycle hook
    op = opts.op = 'beforeCreate'
    return utils.resolve(self[op](props, opts)).then(function (_props) {
      // Allow for re-assignment from lifecycle hook
      props = utils.isUndefined(_props) ? props : _props

      // Deep pre-create belongsTo relations
      const belongsToRelationData = {}
      opts.with || (opts.with = [])
      let tasks = []
      utils.forEachRelation(self, opts, function (def, optsCopy) {
        const relationData = def.getLocalField(props)
        if (def.type === belongsToType && relationData) {
          // Create belongsTo relation first because we need a generated id to
          // attach to the child
          tasks.push(def.getRelation().create(relationData, optsCopy).then(function (data) {
            const relatedRecord = optsCopy.raw ? data.data : data
            def.setLocalField(belongsToRelationData, relatedRecord)
            def.setForeignKey(props, relatedRecord)
          }))
        }
      })
      return utils.Promise.all(tasks).then(function () {
        // Now delegate to the adapter for the main create
        op = opts.op = 'create'
        self.dbg(op, props, opts)
        return utils.resolve(self.getAdapter(adapter)[op](self, self.toJSON(props, { with: opts.pass || [] }), opts))
      }).then(function (data) {
        const createdRecord = opts.raw ? data.data : data
        // Deep post-create hasMany and hasOne relations
        tasks = []
        utils.forEachRelation(self, opts, function (def, optsCopy) {
          const relationData = def.getLocalField(props)
          if (!relationData) {
            return
          }
          let task
          // Create hasMany and hasOne after the main create because we needed
          // a generated id to attach to these items
          if (def.type === hasManyType) {
            def.setForeignKey(createdRecord, relationData)
            task = def.getRelation().createMany(relationData, optsCopy).then(function (data) {
              def.setLocalField(createdRecord, opts.raw ? data.data : data)
            })
          } else if (def.type === hasOneType) {
            def.setForeignKey(createdRecord, relationData)
            task = def.getRelation().create(relationData, optsCopy).then(function (data) {
              def.setLocalField(createdRecord, opts.raw ? data.data : data)
            })
          } else if (def.type === belongsToType && def.getLocalField(belongsToRelationData)) {
            def.setLocalField(createdRecord, def.getLocalField(belongsToRelationData))
          }
          if (task) {
            tasks.push(task)
          }
        })
        return utils.Promise.all(tasks).then(function () {
          return data
        })
      })
    }).then(function (result) {
      result = self._end(result, opts)
      // afterCreate lifecycle hook
      op = opts.op = 'afterCreate'
      return utils.resolve(self[op](props, opts, result)).then(function (_result) {
        // Allow for re-assignment from lifecycle hook
        return utils.isUndefined(_result) ? result : _result
      })
    })
  },

  createInstance (props, opts) {
    return this.createRecord(props, opts)
  },

  /**
   * Given an array of records, batch create them via an adapter.
   *
   * {@link Mapper#beforeCreateMany} will be called before calling the adapter.
   * {@link Mapper#afterCreateMany} will be called after calling the adapter.
   *
   * @name Mapper#createMany
   * @method
   * @param {Array} records Array of records to be created in one batch.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * updated data. If `true` return a response object that includes the updated
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to create in a cascading
   * create if `records` contains nested relations. NOT performed in a
   * transaction. Each nested create will result in another {@link Mapper#createMany}
   * call.
   * @param {string[]} [opts.pass=[]] Relations to send to the adapter as part
   * of the payload. Normally relations are not sent.
   * @return {Promise}
   */
  createMany (records, opts) {
    let op, adapter
    const self = this

    // Default values for arguments
    records || (records = [])
    opts || (opts = {})

    // Fill in "opts" with the Mapper's configuration
    utils._(self, opts)
    adapter = opts.adapter = self.getAdapterName(opts)

    // beforeCreateMany lifecycle hook
    op = opts.op = 'beforeCreateMany'
    return utils.resolve(self[op](records, opts)).then(function (_records) {
      // Allow for re-assignment from lifecycle hook
      records = utils.isUndefined(_records) ? records : _records

      // Deep pre-create belongsTo relations
      const belongsToRelationData = {}
      opts.with || (opts.with = [])
      let tasks = []
      utils.forEachRelation(self, opts, function (def, optsCopy) {
        const relationData = records.map(function (record) {
          return def.getLocalField(record)
        }).filter(function (relatedRecord) {
          return relatedRecord
        })
        if (def.type === belongsToType && relationData.length === records.length) {
          // Create belongsTo relation first because we need a generated id to
          // attach to the child
          tasks.push(def.getRelation().createMany(relationData, optsCopy).then(function (data) {
            const relatedRecords = optsCopy.raw ? data.data : data
            def.setLocalField(belongsToRelationData, relatedRecords)
            records.forEach(function (record, i) {
              def.setForeignKey(record, relatedRecords[i])
            })
          }))
        }
      })
      return utils.Promise.all(tasks).then(function () {
        // Now delegate to the adapter
        op = opts.op = 'createMany'
        const json = records.map(function (record) {
          return self.toJSON(record, { with: opts.pass || [] })
        })
        self.dbg(op, records, opts)
        return utils.resolve(self.getAdapter(adapter)[op](self, json, opts))
      }).then(function (data) {
        const createdRecords = opts.raw ? data.data : data

        // Deep post-create hasOne relations
        tasks = []
        utils.forEachRelation(self, opts, function (def, optsCopy) {
          const relationData = records.map(function (record) {
            return def.getLocalField(record)
          }).filter(function (relatedRecord) {
            return relatedRecord
          })
          if (relationData.length !== records.length) {
            return
          }
          const belongsToData = def.getLocalField(belongsToRelationData)
          let task
          // Create hasMany and hasOne after the main create because we needed
          // a generated id to attach to these items
          if (def.type === hasManyType) {
            // Not supported
            self.log('warn', 'deep createMany of hasMany type not supported!')
          } else if (def.type === hasOneType) {
            createdRecords.forEach(function (createdRecord, i) {
              def.setForeignKey(createdRecord, relationData[i])
            })
            task = def.getRelation().createMany(relationData, optsCopy).then(function (data) {
              const relatedData = opts.raw ? data.data : data
              createdRecords.forEach(function (createdRecord, i) {
                def.setLocalField(createdRecord, relatedData[i])
              })
            })
          } else if (def.type === belongsToType && belongsToData && belongsToData.length === createdRecords.length) {
            createdRecords.forEach(function (createdRecord, i) {
              def.setLocalField(createdRecord, belongsToData[i])
            })
          }
          if (task) {
            tasks.push(task)
          }
        })
        return utils.Promise.all(tasks).then(function () {
          return data
        })
      })
    }).then(function (result) {
      result = self._end(result, opts)
      // afterCreateMany lifecycle hook
      op = opts.op = 'afterCreateMany'
      return utils.resolve(self[op](records, opts, result)).then(function (_result) {
        // Allow for re-assignment from lifecycle hook
        return utils.isUndefined(_result) ? result : _result
      })
    })
  },

  /**
   * Create an unsaved, uncached instance of this Mapper's
   * {@link Mapper#recordClass}.
   *
   * Returns `props` if `props` is already an instance of
   * {@link Mapper#recordClass}.
   *
   * @name Mapper#createRecord
   * @method
   * @param {Object} props The initial properties of the new unsaved record.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.noValidate=false] Whether to skip validation on the
   * initial properties.
   * @return {Object} The unsaved record.
   */
  createRecord (props, opts) {
    const self = this
    const recordClass = self.recordClass
    const relationList = self.relationList || []
    relationList.forEach(function (def) {
      const relatedMapper = def.getRelation()
      const relationData = def.getLocalField(props)
      if (utils.isArray(relationData) && relationData.length && !relatedMapper.is(relationData[0])) {
        def.setLocalField(props, relationData.map(function (relationDataItem) {
          return def.getRelation().createRecord(relationDataItem)
        }))
      } else if (utils.isObject(relationData) && !relatedMapper.is(relationData)) {
        def.setLocalField(props, def.getRelation().createRecord(relationData))
      }
    })
    // Check to make sure "props" is not already an instance of this Mapper.
    return recordClass ? (props instanceof recordClass ? props : new recordClass(props, opts)) : props // eslint-disable-line
  },

  /**
   * Lifecycle invocation method.
   *
   * @name Mapper#crud
   * @method
   * @param {string} method Name of the lifecycle method to invoke.
   * @param {...*} args Arguments to pass to the lifecycle method.
   * @return {Promise}
   */
  crud (method, ...args) {
    const self = this
    const config = self.lifecycleMethods[method]
    if (!config) {
      throw new Error(`${method}: No such CRUD method!`)
    }

    const upper = `${method.charAt(0).toUpperCase()}${method.substr(1)}`
    const before = `before${upper}`
    const after = `after${upper}`

    let op, adapter

    // Default values for arguments
    config.defaults.forEach(function (value, i) {
      if (utils.isUndefined(args[i])) {
        args[i] = utils.copy(value)
      }
    })

    const opts = args[args.length - 1]

    // Fill in "opts" with the Mapper's configuration
    utils._(self, opts)
    adapter = opts.adapter = self.getAdapterName(opts)

    // before lifecycle hook
    op = opts.op = before
    return utils.resolve(self[op](...args)).then(function (_value) {
      if (!utils.isUndefined(config.beforeAssign)) {
        // Allow for re-assignment from lifecycle hook
        args[config.beforeAssign] = utils.isUndefined(_value) ? args[config.beforeAssign] : _value
      }
      // Now delegate to the adapter
      op = opts.op = method
      args = config.adapterArgs ? config.adapterArgs(self, ...args) : args
      self.dbg(op, ...args)
      return utils.resolve(self.getAdapter(adapter)[op](self, ...args))
    }).then(function (result) {
      result = self._end(result, opts, !!config.skip)
      args.push(result)
      // after lifecycle hook
      op = opts.op = after
      return utils.resolve(self[op](...args)).then(function (_result) {
        // Allow for re-assignment from lifecycle hook
        return utils.isUndefined(_result) ? result : _result
      })
    })
  },

  /**
   * Using an adapter, destroy the record with the primary key specified by the
   * `id` argument.
   *
   * {@link Mapper#beforeDestroy} will be called before destroying the record.
   * {@link Mapper#afterDestroy} will be called after destroying the record.
   *
   * @name Mapper#destroy
   * @method
   * @param {(string|number)} id The primary key of the record to destroy.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * ejected data (if any). If `true` return a response object that includes the
   * ejected data (if any) and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to destroy in a cascading
   * delete. NOT performed in a transaction.
   * @return {Promise}
   */
  destroy (id, opts) {
    return this.crud('destroy', id, opts)
  },

  /**
   * Using the `query` argument, destroy the selected records via an adapter.
   * If no `query` is provided then all records will be destroyed.
   *
   * {@link Mapper#beforeDestroyAll} will be called before destroying the records.
   * {@link Mapper#afterDestroyAll} will be called after destroying the records.
   *
   * @name Mapper#destroyAll
   * @method
   * @param {Object} [query={}] Selection query.
   * @param {Object} [query.where] Filtering criteria.
   * @param {number} [query.skip] Number to skip.
   * @param {number} [query.limit] Number to limit to.
   * @param {Array} [query.orderBy] Sorting criteria.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * ejected data (if any). If `true` return a response object that includes the
   * ejected data (if any) and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to destroy in a cascading
   * delete. NOT performed in a transaction.
   * @return {Promise}
   */
  destroyAll (query, opts) {
    return this.crud('destroyAll', query, opts)
  },

  /**
   * Retrieve via an adapter the record with the given primary key.
   *
   * {@link Mapper#beforeFind} will be called before calling the adapter.
   * {@link Mapper#afterFind} will be called after calling the adapter.
   *
   * @name Mapper#find
   * @method
   * @param {(string|number)} id The primary key of the record to retrieve.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * updated data. If `true` return a response object that includes the updated
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to eager load in the request.
   * @return {Promise}
   */
  find (id, opts) {
    return this.crud('find', id, opts)
  },

  /**
   * Using the `query` argument, select records to pull from an adapter.
   * Expects back from the adapter the array of selected records.
   *
   * {@link Mapper#beforeFindAll} will be called before calling the adapter.
   * {@link Mapper#afterFindAll} will be called after calling the adapter.
   *
   * @name Mapper#findAll
   * @method
   * @param {Object} [query={}] Selection query.
   * @param {Object} [query.where] Filtering criteria.
   * @param {number} [query.skip] Number to skip.
   * @param {number} [query.limit] Number to limit to.
   * @param {Array} [query.orderBy] Sorting criteria.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * resulting data. If `true` return a response object that includes the
   * resulting data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to eager load in the request.
   * @return {Promise}
   */
  findAll (query, opts) {
    return this.crud('findAll', query, opts)
  },

  /**
   * Return the registered adapter with the given name or the default adapter if
   * no name is provided.
   *
   * @name Mapper#getAdapter
   * @method
   * @param {string} [name] The name of the adapter to retrieve.
   * @return {Adapter} The adapter.
   */
  getAdapter (name) {
    const self = this
    self.dbg('getAdapter', 'name:', name)
    const adapter = self.getAdapterName(name)
    if (!adapter) {
      throw new ReferenceError(`${adapter} not found!`)
    }
    return self.getAdapters()[adapter]
  },

  /**
   * Return the name of a registered adapter based on the given name or options,
   * or the name of the default adapter if no name provided.
   *
   * @name Mapper#getAdapterName
   * @method
   * @param {(Object|string)} [opts] The name of an adapter or options, if any.
   * @return {string} The name of the adapter.
   */
  getAdapterName (opts) {
    opts || (opts = {})
    if (utils.isString(opts)) {
      opts = { adapter: opts }
    }
    return opts.adapter || opts.defaultAdapter
  },

  /**
   * @name Mapper#getAdapters
   * @method
   */
  getAdapters () {
    return this._adapters
  },

  getSchema () {
    return this.schema
  },

  /**
   * Usage:
   *
   * User.hasMany(Post, {
   *   localField: 'my_posts'
   * })
   *
   * @name Mapper#hasMany
   * @method
   */
  hasMany (relatedMapper, opts) {
    return hasMany(relatedMapper, opts)(this)
  },

  /**
   * Usage:
   *
   * User.hasOne(Profile, {
   *   localField: '_profile'
   * })
   *
   * @name Mapper#hasOne
   * @method
   */
  hasOne (relatedMapper, opts) {
    return hasOne(relatedMapper, opts)(this)
  },

  /**
   * Return whether `record` is an instance of this Mappers's recordClass.
   *
   * @name Mapper#is
   * @method
   * @param {Object} record The record to check.
   * @return {boolean} Whether `record` is an instance of this Mappers's
   * {@ link Mapper#recordClass}.
   */
  is (record) {
    const recordClass = this.recordClass
    return recordClass ? record instanceof recordClass : false
  },

  /**
   * Register an adapter on this mapper under the given name.
   *
   * @name Mapper#registerAdapter
   * @method
   * @param {string} name The name of the adapter to register.
   * @param {Adapter} adapter The adapter to register.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.default=false] Whether to make the adapter the
   * default adapter for this Mapper.
   */
  registerAdapter (name, adapter, opts) {
    const self = this
    opts || (opts = {})
    self.getAdapters()[name] = adapter
    // Optionally make it the default adapter for the target.
    if (opts === true || opts.default) {
      self.defaultAdapter = name
    }
  },

  /**
   * Using the `query` argument, select records to pull from an adapter.
   * Expects back from the adapter the array of selected records.
   *
   * {@link Mapper#beforeSum} will be called before calling the adapter.
   * {@link Mapper#afterSum} will be called after calling the adapter.
   *
   * @name Mapper#sum
   * @method
   * @param {string} field The field to sum.
   * @param {Object} [query={}] Selection query.
   * @param {Object} [query.where] Filtering criteria.
   * @param {number} [query.skip] Number to skip.
   * @param {number} [query.limit] Number to limit to.
   * @param {Array} [query.orderBy] Sorting criteria.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * resulting data. If `true` return a response object that includes the
   * resulting data and metadata about the operation.
   * @return {Promise}
   */
  sum (field, query, opts) {
    return this.crud('sum', field, query, opts)
  },

  /**
   * Return a plain object representation of the given record.
   *
   * @name Mapper#toJSON
   * @method
   * @param {Object} record Record from which to create a plain object
   * representation.
   * @param {Object} [opts] Configuration options.
   * @param {string[]} [opts.with] Array of relation names or relation fields
   * to include in the representation.
   * @return {Object} Plain object representation of the record.
   */
  toJSON (record, opts) {
    const self = this
    opts || (opts = {})
    const relationFields = (self ? self.relationFields : []) || []
    let json = {}
    let properties
    if (self && self.schema) {
      properties = self.schema.properties || {}
      // TODO: Make this work recursively
      utils.forOwn(properties, function (opts, prop) {
        json[prop] = utils.plainCopy(record[prop])
      })
    }
    properties || (properties = {})
    if (!opts.strict) {
      utils.forOwn(record, function (value, key) {
        if (!properties[key] && relationFields.indexOf(key) === -1) {
          json[key] = utils.plainCopy(value)
        }
      })
    }
    // The user wants to include relations in the resulting plain object
    // representation
    if (self && opts.withAll) {
      opts.with = relationFields.slice()
    }
    if (self && opts.with) {
      if (utils.isString(opts.with)) {
        opts.with = [opts.with]
      }
      utils.forEachRelation(self, opts, function (def, optsCopy) {
        const relationData = def.getLocalField(record)
        if (relationData) {
          // The actual recursion
          if (utils.isArray(relationData)) {
            def.setLocalField(json, relationData.map(function (item) {
              return def.getRelation().toJSON(item, optsCopy)
            }))
          } else {
            def.setLocalField(json, def.getRelation().toJSON(relationData, optsCopy))
          }
        }
      })
    }
    return json
  },

  /**
   * Using an adapter, update the record with the primary key specified by the
   * `id` argument.
   *
   * {@link Mapper#beforeUpdate} will be called before updating the record.
   * {@link Mapper#afterUpdate} will be called after updating the record.
   *
   * @name Mapper#update
   * @method
   * @param {(string|number)} id The primary key of the record to update.
   * @param {Object} props The update to apply to the record.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * updated data. If `true` return a response object that includes the updated
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to update in a cascading
   * update if `props` contains nested updates to relations. NOT performed in a
   * transaction.
   * @return {Promise}
   */
  update (id, props, opts) {
    return this.crud('update', id, props, opts)
  },

  /**
   * Using the `query` argument, perform the a single updated to the selected
   * records. Expects back from the adapter an array of the updated records.
   *
   * {@link Mapper#beforeUpdateAll} will be called before making the update.
   * {@link Mapper#afterUpdateAll} will be called after making the update.
   *
   * @name Mapper#updateAll
   * @method
   * @param {Object} props Update to apply to selected records.
   * @param {Object} [query={}] Selection query.
   * @param {Object} [query.where] Filtering criteria.
   * @param {number} [query.skip] Number to skip.
   * @param {number} [query.limit] Number to limit to.
   * @param {Array} [query.orderBy] Sorting criteria.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * updated data. If `true` return a response object that includes the updated
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to update in a cascading
   * update if `props` contains nested updates to relations. NOT performed in a
   * transaction.
   * @return {Promise}
   */
  updateAll (props, query, opts) {
    return this.crud('updateAll', props, query, opts)
  },

  /**
   * Given an array of updates, perform each of the updates via an adapter. Each
   * "update" is a hash of properties with which to update an record. Each
   * update must contain the primary key to be updated.
   *
   * {@link Mapper#beforeUpdateMany} will be called before making the update.
   * {@link Mapper#afterUpdateMany} will be called after making the update.
   *
   * @name Mapper#updateMany
   * @method
   * @param {Array} records Array up record updates.
   * @param {Object} [opts] Configuration options.
   * @param {boolean} [opts.adapter={@link Mapper#defaultAdapter}] Name of the
   * adapter to use.
   * @param {boolean} [opts.notify={@link Mapper#notify}] Whether to emit
   * lifecycle events.
   * @param {boolean} [opts.raw={@link Mapper#raw}] If `false`, return the
   * updated data. If `true` return a response object that includes the updated
   * data and metadata about the operation.
   * @param {string[]} [opts.with=[]] Relations to update in a cascading
   * update if each record update contains nested updates for relations. NOT
   * performed in a transaction.
   * @return {Promise}
   */
  updateMany (records, opts) {
    return this.crud('updateMany', records, opts)
  },

  /**
   * TODO
   *
   * @name Mapper#validate
   * @method
   * @param {Object|Array} record The record or records to validate.
   * @param {Object} [opts] Configuration options.
   */
  validate (record, opts) {
    const self = this
    if (!self.getSchema()) {
      throw new Error('no schema!')
    }
    if (utils.isArray(record)) {
      return record.map(function (_record) {
        return self.schema.validate(_record, opts)
      })
    } else if (utils.isObject(record)) {
      return self.schema.validate(record, opts)
    } else {
      throw new Error('not a record!')
    }
  }
})