import { IApplication } from '@/domain/IApplication';
import { AsyncLazy } from '@/infrastructure/Threading/AsyncLazy';
import { IApplicationFactory } from './IApplicationFactory';
import { parseApplication } from './Parser/ApplicationParser';

export type ApplicationGetter = () => IApplication;
const ApplicationGetter: ApplicationGetter = parseApplication;

export class ApplicationFactory implements IApplicationFactory {
    public static readonly Current: IApplicationFactory = new ApplicationFactory(ApplicationGetter);
    private readonly getter: AsyncLazy<IApplication>;
    protected constructor(costlyGetter: ApplicationGetter) {
        if (!costlyGetter) {
            throw new Error('undefined getter');
        }
        this.getter = new AsyncLazy<IApplication>(() => Promise.resolve(costlyGetter()));
    }
    public getApp(): Promise<IApplication> {
        return this.getter.getValue();
    }
}