import { NgModule, ModuleWithProviders, SkipSelf, Optional } from '@angular/core'
import { Configuration } from './configuration'
import { HttpClient } from '@angular/common/http'

@NgModule({
	imports: [],
	declarations: [],
	exports: [],
	providers: [],
})
export class ApiModule {
	public static forRoot(configurationFactory: () => Configuration): ModuleWithProviders<ApiModule> {
		return {
			ngModule: ApiModule,
			providers: [{ provide: Configuration, useFactory: configurationFactory }],
		}
	}

	constructor(@Optional() @SkipSelf() parentModule: ApiModule, @Optional() http: HttpClient) {
		if (parentModule) {
			throw new Error('ApiModule is already loaded. Import in your base AppModule only.')
		}
		if (!http) {
			throw new Error(
				'You need to import the HttpClientModule in your AppModule! \n' +
					'See also https://github.com/angular/angular/issues/20575',
			)
		}
	}
}