Layer Chat

layer.js

import {Injectable, Inject} from 'angular2/core';
import {Http, HTTP_PROVIDERS, Headers} from 'angular2/http';
import 'rxjs/add/operator/map';
import {Observable, Subject} from 'rxjs';
import * as layer from 'layer-websdk';
import * as _ from 'lodash';

export class Layer {
	layerClient: layer.Client;
	http: Http;
	participants: any;
	ready: boolean;
	messageStream: Subject<any>;

	constructor(layerAppId, participants, http: Http) {
		this.http = http;
		this.ready = false;
		this.participants = participants;

		this.layerClient = new layer.Client({
			appId: layerAppId
		});

		this.onReady(() => {
			var ws = new WebSocket('wss://api.layer.com/websocket?session_token=' + this.layerClient.sessionToken,
				'layer-1.0');
			this.messageStream = Observable.fromEvent(ws, 'message').filter(event => {
				var message = JSON.parse(event.data);
				return message.type == 'change';
			}).map(event => JSON.parse(event.data).body);
		});
	}

	getMessageStream() {
		return this.messageStream;
	}

	login(getToken) {
		this.layerClient.on('challenge', event => {
			getToken(event.nonce)
				.subscribe(token => {
					event.callback(token);
				}, error => {
					console.log(error);
				})
		});
	}

	onReady(callback) {
		if (!!this.ready) {
			callback;
		} else {
			this.layerClient.on('ready', callback);	
		}
	}

	getConversation() {
		return this._get('https://api.layer.com/conversations')
		.map(conversations => {
			var items = conversations.filter(conversation => _.isEqual(this.participants, conversation.participants));
			if (items) {
				return _.first(items);
			}
			return null;
		});
	}

	getMessages(conversation) {
		return this._get(conversation.messages_url);
	}

	sendMessage(message) {
		var conversation = this.layerClient.createConversation({
			participants: this.participants,
			distinct: true
		});

		var messagePart = new layer.MessagePart({
			mimeType: 'text/plain',
			body: message
		});

		conversation.createMessage({ parts: [messagePart] }).send();
	}

	private _get(url) {
		var headers = new Headers();
		headers.append('Accept', 'application/vnd.layer+json; version=1.0');
		headers.append('Authorization', 'Layer session-token=\'' + this.layerClient.sessionToken + '\'');

		return this.http.get(url, { headers: headers }).map(res => res.json());
	}
}