import { Injectable, APP_INITIALIZER } from "@angular/core";
import { HttpClient } from "@angular/common/http";

function getHostUrl() {
    return '//'+location.host;
}

@Injectable()
export default class ConfigService {

    public config: any;

    constructor(private http: HttpClient) {
    }

    load(path: string) {
        return new Promise((resolve, reject) => {
            this.http.get(getHostUrl()+path)
                .subscribe(data => {
                    this.config = data;
                    resolve(true);
                })
        });
    }

    static getAppInitializer(path: string) {
        return {
            provide: APP_INITIALIZER,
            useFactory: (config: ConfigService) => () => config.load(path),
            deps: [ ConfigService ],
            multi: true
        };
    }
}