import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptionsArgs, RequestOptions, RequestMethod, URLSearchParams } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import { AdalService } from './adal.service';
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/mergeMap';
import 'rxjs/add/observable/throw';

@Injectable()
export class AuthHttp {
	constructor(private http: Http
		, private adalService: AdalService
	) {
	}

	get(url: string, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Get });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}

	post(url: string, body: any, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Post, body: body });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}

	delete(url: string, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Delete });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}


	patch(url: string, body: any, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Patch, body: body });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}

	put(url: string, body: any, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Put, body: body });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}

	head(url: string, options?: RequestOptionsArgs): Observable<any> {
		let options1 = new RequestOptions({ method: RequestMethod.Put });
		options1 = options1.merge(options);
		return this.sendRequest(url, options1);
	}

	private sendRequest(url: string, options: RequestOptionsArgs): Observable<string> {
		// make a copy
		let options1 = new RequestOptions();
		options1.method = options.method;
		options1 = options1.merge(options);
		let resource = this.adalService.GetResourceForEndpoint(url);
		let authenticatedCall: Observable<string>;
		if (resource) {
			if (this.adalService.userInfo.isAuthenticated) {
				authenticatedCall = this.adalService.acquireToken(resource)
					.flatMap((token: string) => {
						if (options1.headers == null) {
							options1.headers = new Headers();
						}
						options1.headers.set('Authorization', 'Bearer ' + token);
						return this.http.request(url, options1)
							.catch(this.handleError);
					});
			}
			else {
				authenticatedCall = Observable.throw(new Error('User Not Authenticated.'));
			}
		}
		else {
			authenticatedCall = this.http.request(url, options).map(this.extractData).catch(this.handleError);
		}

		return authenticatedCall;
	}

	private extractData(res: Response) {
		if (res.status < 200 || res.status >= 300) {
			throw new Error('Bad response status: ' + res.status);
		}

		let body = {};
		// if there is some content, parse it
		if (res.status !== 204) {
			body = res.json();
		}

		return body || {};
	}

	private handleError(error: any) {
		return Observable.throw(error);
	}
}