import { HttpEvent, HttpRequest } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';

import { HTTP_SERVICE_INTERCEPTORS, HttpServiceHandler, HttpServiceInterceptor } from '../dataset-api/http.service';
import { HttpRequestOptions } from '../model/internal/http-requests';
import { Settings } from '../model/settings/settings';
import { SettingsService } from '../settings/settings.service';

@Injectable()
export class CorsProxyInterceptor implements HttpServiceInterceptor {

    constructor(
        private settingsSrvc: SettingsService<Settings>
    ) { }

    public intercept(
        req: HttpRequest<any>, metadata: HttpRequestOptions, next: HttpServiceHandler
    ): Observable<HttpEvent<any>> {
        const settings = this.settingsSrvc.getSettings();
        if (settings && settings.proxyUrl && settings.proxyUrlsStartWith) {
            const startWith = settings.proxyUrlsStartWith.find(e => req.url.startsWith(e));
            if (startWith) {
                const clone = req.clone({ url: settings.proxyUrl + req.url });
                return next.handle(clone, metadata);
            }
        }
        return next.handle(req, metadata);
    }
}

export const CorsProxyInterceptorProvider = {
    provide: HTTP_SERVICE_INTERCEPTORS,
    useClass: CorsProxyInterceptor,
    multi: true
};