import { Injectable } from '@angular/core';
import { BehaviorSubject, Observable }  from 'rxjs';
import { HttpClient, HttpParams, HttpHeaders } from '@angular/common/http';

import { ConfigData } from './configdata';

var Buffer = require('buffer/').Buffer;

@Injectable({
  providedIn: 'root'
})
export class XeroService {
	beUrl = ConfigData.Be_URL;
	clientId: string = '';
	clientSecret: string = '';
	xeroToken: any = {
		accessToken: '',
		refreshToken: '',
		expiresIn: 0,
		scope: '',
		tokenType: ''
	};
	private _clientIdUpdated: BehaviorSubject<string> = new BehaviorSubject(this.clientId);
	private _clientSecretUpdated: BehaviorSubject<string> = new BehaviorSubject(this.clientSecret);
	private _tokenUpdated: BehaviorSubject<any> = new BehaviorSubject(this.xeroToken);
	public readonly clientIdUpdate: Observable<string> = this._clientIdUpdated.asObservable();
	public readonly clientSecretUpdate: Observable<string> = this._clientSecretUpdated.asObservable();
	public readonly tokenUpdate: Observable<any> = this._tokenUpdated.asObservable();
	private reqHeaders: HttpHeaders;

	constructor(
		private http: HttpClient
	) {
		var auth = 'Basic ' + Buffer.from(ConfigData.UsrPwd).toString('base64');
		this.reqHeaders = new HttpHeaders().set('Authorization', auth);
		this.getXeroConfig();
	}

	getXeroConfig(){
		let obs = this.http.get<{message: string, xeroConfig: any}>(this.beUrl+'api/xero', { headers:this.reqHeaders, observe: 'response'});

		obs.subscribe(xeroDataResponse => {
			if (xeroDataResponse.status == 200) {
				this.clientId = xeroDataResponse.body!.xeroConfig.clientId;
				this.clientSecret = xeroDataResponse.body!.xeroConfig.clientSecret;
				this._clientIdUpdated.next(Object.assign({}, this).clientId);
				this._clientSecretUpdated.next(Object.assign({}, this).clientSecret);
			} else {
				console.log('No config in DB!');
			}
		});
		
		return obs;
	}

	getXeroAccessToken(code: string){
		this.getXeroConfig().subscribe(xeroDataResponse => {
			console.log('XAT: '+this.clientId);
			var xeroAuth = 'Basic ' + Buffer.from(`${this.clientId}:${this.clientSecret}`).toString('base64');
			var xeroHeaders = new HttpHeaders().set('Authorization', xeroAuth).append('Content-Type', 'application/x-www-form-urlencoded');
			let obs = this.http.post('https://identity.xero.com/connect/token', `grant_type=authorization_code&code=${code}&redirect_uri=http://localhost:4200/test` , {headers: xeroHeaders, observe: 'response'})
			obs.subscribe(tokenData => {
				if (tokenData.status == 200) {
					console.log(tokenData.body!);
					this.xeroToken = tokenData.body!;
					this._tokenUpdated.next(Object.assign({}, this).xeroToken);
				} else {
					console.log('Error: '+tokenData.status);
				}
			});
		});
	}
}