import { ModuleWithProviders, NgModule, InjectionToken, Injector } from '@angular/core';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { NaTranslateService } from './na-translate.service';
import { HttpClient } from '@angular/common/http';
// import { MultiTranslateHttpLoader, ITranslationResource } from 'ngx-translate-multi-http-loader';
import { MultiTranslateHttpLoader, ITranslationResource } from './multi-http-loader';

export const NA_DEFAULT_RESOURCES = new InjectionToken<ITranslationResource>(
  'NA_DEFAULT_RESOURCES'
);

export function createTranslateLoader(http: HttpClient, resources: ITranslationResource[], injector: Injector) {
  return new MultiTranslateHttpLoader(http, resources, injector);
}

@NgModule({
  imports: [
    TranslateModule
  ],
  exports: [
    TranslateModule,
  ],
  providers: [
    NaTranslateService
  ]
})
export class NaTranslateModule {
  static forRoot(resources: ITranslationResource[] = []): ModuleWithProviders<NaTranslateModule> {
    return {
      ngModule: NaTranslateModule,
      providers: [
        { provide: NA_DEFAULT_RESOURCES, useValue: resources },
        ...TranslateModule.forRoot({
          loader: {
            provide: TranslateLoader,
            useFactory: (createTranslateLoader),
            deps: [HttpClient, NA_DEFAULT_RESOURCES, Injector]
          },
          // 隔离服务
          isolate: true,
          useDefaultLang: true
        }).providers
      ]
    };
  }
}