/**
 * Copyright (c) 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule DraftEntity
 * @format
 * @flow
 */

import type { DraftEntityMutability } from './DraftEntityMutability';
import type { DraftEntityType } from './DraftEntityType';

var DraftEntityInstance = require('./DraftEntityInstance');
var Immutable = require('immutable');

var invariant = require('fbjs/lib/invariant');

var { Map } = Immutable;

var instances: Map<string, DraftEntityInstance> = Map();
var instanceKey = 0;

/**
 * Temporary utility for generating the warnings
 */
function logWarning(oldMethodCall, newMethodCall) {
  console.warn('WARNING: ' + oldMethodCall + ' will be deprecated soon!\nPlease use "' + newMethodCall + '" instead.');
}

export type DraftEntityMapObject = {
  getLastCreatedEntityKey: () => string;

  create: (type: DraftEntityType, mutability: DraftEntityMutability, data?: Object) => string;

  add: (instance: DraftEntityInstance) => string;

  get: (key: string) => DraftEntityInstance;

  mergeData: (key: string, toMerge: { [key: string]: any }) => DraftEntityInstance;

  replaceData: (key: string, newData: { [key: string]: any }) => DraftEntityInstance;

  __getLastCreatedEntityKey: () => string;

  __create: (type: DraftEntityType, mutability: DraftEntityMutability, data?: Object) => string;

  __add: (instance: DraftEntityInstance) => string;

  __get: (key: string) => DraftEntityInstance;

  __mergeData: (key: string, toMerge: { [key: string]: any }) => DraftEntityInstance;

  __replaceData: (key: string, newData: { [key: string]: any }) => DraftEntityInstance;
};

/**
 * A "document entity" is an object containing metadata associated with a
 * piece of text in a ContentBlock.
 *
 * For example, a `link` entity might include a `uri` property. When a
 * ContentBlock is rendered in the browser, text that refers to that link
 * entity may be rendered as an anchor, with the `uri` as the href value.
 *
 * In a ContentBlock, every position in the text may correspond to zero
 * or one entities. This correspondence is tracked using a key string,
 * generated via DraftEntity.create() and used to obtain entity metadata
 * via DraftEntity.get().
 */
var DraftEntity: DraftEntityMapObject = {
  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.getLastCreatedEntityKey' instead.
   * ---
   * Get the random key string from whatever entity was last created.
   * We need this to support the new API, as part of transitioning to put Entity
   * storage in contentState.
   */
  getLastCreatedEntityKey: function (): string {
    logWarning('DraftEntity.getLastCreatedEntityKey', 'contentState.getLastCreatedEntityKey');
    return DraftEntity.__getLastCreatedEntityKey();
  },

  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.createEntity' instead.
   * ---
   * Create a DraftEntityInstance and store it for later retrieval.
   *
   * A random key string will be generated and returned. This key may
   * be used to track the entity's usage in a ContentBlock, and for
   * retrieving data about the entity at render time.
   */
  create: function (type: DraftEntityType, mutability: DraftEntityMutability, data?: Object): string {
    logWarning('DraftEntity.create', 'contentState.createEntity');
    return DraftEntity.__create(type, mutability, data);
  },

  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.addEntity' instead.
   * ---
   * Add an existing DraftEntityInstance to the DraftEntity map. This is
   * useful when restoring instances from the server.
   */
  add: function (instance: DraftEntityInstance): string {
    logWarning('DraftEntity.add', 'contentState.addEntity');
    return DraftEntity.__add(instance);
  },

  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.getEntity' instead.
   * ---
   * Retrieve the entity corresponding to the supplied key string.
   */
  get: function (key: string): DraftEntityInstance {
    logWarning('DraftEntity.get', 'contentState.getEntity');
    return DraftEntity.__get(key);
  },

  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.mergeEntityData' instead.
   * ---
   * Entity instances are immutable. If you need to update the data for an
   * instance, this method will merge your data updates and return a new
   * instance.
   */
  mergeData: function (key: string, toMerge: { [key: string]: any }): DraftEntityInstance {
    logWarning('DraftEntity.mergeData', 'contentState.mergeEntityData');
    return DraftEntity.__mergeData(key, toMerge);
  },

  /**
   * WARNING: This method will be deprecated soon!
   * Please use 'contentState.replaceEntityData' instead.
   * ---
   * Completely replace the data for a given instance.
   */
  replaceData: function (key: string, newData: { [key: string]: any }): DraftEntityInstance {
    logWarning('DraftEntity.replaceData', 'contentState.replaceEntityData');
    return DraftEntity.__replaceData(key, newData);
  },

  // ***********************************WARNING******************************
  // --- the above public API will be deprecated in the next version of Draft!
  // The methods below this line are private - don't call them directly.

  /**
   * Get the random key string from whatever entity was last created.
   * We need this to support the new API, as part of transitioning to put Entity
   * storage in contentState.
   */
  __getLastCreatedEntityKey: function (): string {
    return '' + instanceKey;
  },

  /**
   * Create a DraftEntityInstance and store it for later retrieval.
   *
   * A random key string will be generated and returned. This key may
   * be used to track the entity's usage in a ContentBlock, and for
   * retrieving data about the entity at render time.
   */
  __create: function (type: DraftEntityType, mutability: DraftEntityMutability, data?: Object): string {
    return DraftEntity.__add(new DraftEntityInstance({ type, mutability, data: data || {} }));
  },

  /**
   * Add an existing DraftEntityInstance to the DraftEntity map. This is
   * useful when restoring instances from the server.
   */
  __add: function (instance: DraftEntityInstance): string {
    var key = '' + ++instanceKey;
    instances = instances.set(key, instance);
    return key;
  },

  /**
   * Retrieve the entity corresponding to the supplied key string.
   */
  __get: function (key: string): DraftEntityInstance {
    var instance = instances.get(key);
    invariant(!!instance, 'Unknown DraftEntity key: %s.', key);
    return instance;
  },

  /**
   * Entity instances are immutable. If you need to update the data for an
   * instance, this method will merge your data updates and return a new
   * instance.
   */
  __mergeData: function (key: string, toMerge: { [key: string]: any }): DraftEntityInstance {
    var instance = DraftEntity.__get(key);
    var newData = { ...instance.getData(), ...toMerge };
    var newInstance = instance.set('data', newData);
    instances = instances.set(key, newInstance);
    return newInstance;
  },

  /**
   * Completely replace the data for a given instance.
   */
  __replaceData: function (key: string, newData: { [key: string]: any }): DraftEntityInstance {
    const instance = DraftEntity.__get(key);
    const newInstance = instance.set('data', newData);
    instances = instances.set(key, newInstance);
    return newInstance;
  }
};

module.exports = DraftEntity;