import {Injectable} from '@angular/core';

import {HTTP_PROVIDERS, Http, XHRBackend, XHRConnection, ConnectionBackend, RequestOptions, RequestOptionsArgs, ResponseOptions, ResponseType, Response, Request, BrowserXhr, XSRFStrategy} from '@angular/http';

import {Observable} from 'rxjs/Observable';

import 'rxjs/add/observable/fromPromise';

import {NSFileSystem} from '../file-system/ns-file-system';

export class NSXSRFStrategy {

public configureRequest(req: any) {

// noop

}

}

@Injectable()

export class NSHttp extends Http {

constructor(backend: ConnectionBackend, defaultOptions: any, private nsFileSystem: NSFileSystem) {

super(backend, defaultOptions);

}

/**

* Performs a request with `get` http method.

* Uses a local file if `~/` resource is requested.

*/

get(url: string, options?: RequestOptionsArgs): Observable<Response | any> {

if (url.indexOf('~') === 0 || url.indexOf('/') === 0) {

// normalize url

url = url.replace('~', '').replace('/', '');

// request from local app resources

return Observable.fromPromise(new Promise((resolve, reject) => {

let app = this.nsFileSystem.currentApp();

let localFile = app.getFile(url);

if (localFile) {

localFile.readText().then((data) => {

resolve(responseOptions(data, 200, url));

}, (err: Object) => {

reject(responseOptions(err, 400, url));

});

} else {

reject(responseOptions('Not Found', 404, url));

}

}));

} else {

return super.get(url, options);

}

}

}

function responseOptions(body: string | Object, status: number, url: string): Response {

return new Response(new ResponseOptions({

body: body,

status: status,

statusText: 'OK',

type: status === 200 ? ResponseType.Default : ResponseType.Error,

url: url

}));

}

export const NS_HTTP_PROVIDERS: any[] = [

HTTP_PROVIDERS,

{ provide: XSRFStrategy, useValue: new NSXSRFStrategy() },

NSFileSystem,

{ provide: Http, useFactory: (backend, options, nsFileSystem) => {

return new NSHttp(backend, options, nsFileSystem);

}, deps: [XHRBackend, RequestOptions, NSFileSystem]

}

];