/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {Injector, NgModule, NgZone} from '@angular/core';

import * as angular from '../angular_js';
import {controllerKey} from '../util';

import {angular1Providers, setTempInjectorRef} from './angular1_providers';
import {$INJECTOR, INJECTOR_KEY, UPGRADE_MODULE_NAME} from './constants';


/**
 * The Ng1Module contains providers for the Ng1Adapter and all the core Angular 1 services;
 * and also holds the `bootstrapNg1()` method fo bootstrapping an upgraded Angular 1 app.
 * @experimental
 */
@NgModule({providers: angular1Providers})
export class UpgradeModule {
  public $injector: angular.IInjectorService;

  constructor(public injector: Injector, public ngZone: NgZone) {}

  /**
   * Bootstrap an Angular 1 application from this NgModule
   * @param element the element on which to bootstrap the Angular 1 application
   * @param [modules] the Angular 1 modules to bootstrap for this application
   * @param [config] optional extra Angular 1 bootstrap configuration
   */
  bootstrap(element: Element, modules: string[] = [], config?: angular.IAngularBootstrapConfig) {
    // Create an ng1 module to bootstrap
    const upgradeModule =
        angular
            .module(UPGRADE_MODULE_NAME, modules)

            .value(INJECTOR_KEY, this.injector)

            .run([
              $INJECTOR,
              ($injector: angular.IInjectorService) => {
                this.$injector = $injector;

                // Initialize the ng1 $injector provider
                setTempInjectorRef($injector);
                this.injector.get($INJECTOR);

                // Put the injector on the DOM, so that it can be "required"
                angular.element(element).data(controllerKey(INJECTOR_KEY), this.injector);

                // Wire up the ng1 rootScope to run a digest cycle whenever the zone settles
                const $rootScope = $injector.get('$rootScope');
                this.ngZone.onMicrotaskEmpty.subscribe(
                    () => this.ngZone.runOutsideAngular(() => $rootScope.$evalAsync()));
              }
            ]);

    // Bootstrap the angular 1 application inside our zone
    this.ngZone.run(() => { angular.bootstrap(element, [upgradeModule.name], config); });
  }
}