twitch-toolkit
Version:
A set of tools to integrate with Twitch API, Twitch Chat and Twitch WebHooks.
213 lines (198 loc) • 7.57 kB
JavaScript
'use strict';
const request = require('request-promise');
const util = require('util');
const eventemitter = require('eventemitter3');
const _ = require('./helpers');
const API_BASE_URL = 'https://api.twitch.tv/helix';
/**
* @class TwitchWebSub
* The Twitch Webhooks implementation, as described in https://dev.twitch.tv/docs/api/webhooks-guide/ .
* The Webhook/WebSub requires a public endpoint on the running express server/application to receive the data from the hub. Without this, its impossible to make this work.
*
* @param {object} config The config object.
* @param {string} config.client_id The client ID of the user to be passed to the Hub (un)subscribe requests.
* @param {string} config.callbackUrl The callback URL that will receive the Hub requests. These requests should be forwarded to the handleRequest method to properly handle these data.
* @param {object} logger The logger object.
*/
function TwitchWebSub(config, logger) {
eventemitter.call(this);
this.config = config;
this.logger = logger;
this.secret = _.uuidv4();
this.subscribersMap = {};
}
/**
* Notifies when a follows event occurs. The response mimics the Get Users Follows endpoint. (https://dev.twitch.tv/docs/api/reference/#get-users-follows)
*
* @param {number} fromId The ID of the user who starts following someone.
* @param {number} toId The ID of the user who has a new follower.
* @return {string} The subscription ID, used to identify the active topic.
* @fires TwitchWebSub#WebSub:user_follows
*/
TwitchWebSub.prototype.topicUserFollowsSubscribe = async function(
fromId,
toId
) {
/**
* Stream User Follows Event
* @event TwitchWebSub#WebSub:user_follows
* @param {object} data The data object received from the Hub.
* @param {string} id The subscription ID.
*/
try {
let topic = API_BASE_URL + '/users/follows?first=1';
if (fromId) {
topic += '&from_id=' + fromId;
} else if (toId) {
topic += '&to_id=' + toId;
}
return this.subscribe(topic, 'user_follows');
} catch (err) {
throw err;
}
};
/**
* Notifies when a stream goes online or offline. The response mimics the Get Streams endpoint. (https://dev.twitch.tv/docs/api/reference/#get-streams)
*
* @param {number} streamUserId The ID of the user whose stream is monitored.
* @return {string} The subscription ID, used to identify the active topic.
* @fires TwitchWebSub#WebSub:stream_up_down
*/
TwitchWebSub.prototype.topicStreamUpDownSubscribe = async function(
streamUserId
) {
/**
* Stream Up/Down Event
* @event TwitchWebSub#WebSub:stream_up_down
* @param {object} data The data object received from the Hub.
* @param {string} id The subscription ID.
*/
try {
let topic = API_BASE_URL + '/streams?user_id=' + streamUserId;
return this.subscribe(topic, 'stream_up_down');
} catch (err) {
throw err;
}
};
/**
* Subscribe to a specific topic that will fires an event when new data is received from the hub.
* The event handler will receive the data object and the subscription ID.
* @param {string} topic The topic name/URL.
* @param {string} eventName The event name that will be fired when new data is received.
* @return {string} The subscription ID, used to identify the active topic.
*/
TwitchWebSub.prototype.subscribe = async function(topic, eventName) {
try {
this.logger.debug('Subscribing WebSub with topic: ' + topic);
let item = {
id: _.uuidv4(),
topic: topic,
eventName: eventName,
subscribedAt: new Date(),
secret: _.generateRandomKey()
};
await request({
url: API_BASE_URL + '/webhooks/hub',
method: 'POST',
headers: {
'Client-ID': this.config.client_id,
'Content-Type': 'application/json'
},
form: {
'hub.callback': this.config.callbackUrl + '?item.id=' + item.id,
'hub.mode': 'subscribe',
'hub.topic': topic,
'hub.lease_seconds': 864000,
'hub.secret': item.secret
},
json: true
});
this.subscribersMap[item.id] = item;
return item.id;
} catch (err) {
throw err;
}
};
/**
* This method will handle the request received by the express server and validate the subscriptions or properly emit the events with the received data.
* @param {object} request The express request object.
* @param {object} response The express response object.
*/
TwitchWebSub.prototype.handleRequest = function(request, response) {
try {
this.logger.debug('Receiving new WebSub request');
if (request.query['hub.challenge']) {
response.send(request.query['hub.challenge']);
} else {
let id = request.query['item.id'];
if (id && this.subscribersMap[id]) {
let item = this.subscribersMap[id];
let data = request.body ? request.body.data : null;
//TODO Validate secret
response.sendStatus(200);
this.emit(item.eventName, data, id);
} else {
response.sendStatus(400);
}
}
} catch (err) {
response.sendStatus(500);
throw err;
}
};
/**
* Unsubscribe from a topic by its ID.
* @param {string} id The subscription ID.
*/
TwitchWebSub.prototype.unsubscribe = async function(id) {
try {
this.logger.debug('Requesting WebSub unsubscription with id: ' + id);
if (this.subscribersMap[id]) {
let item = this.subscribersMap[id];
await request({
url: API_BASE_URL + '/webhooks/hub',
method: 'POST',
headers: {
'Client-ID': this.config.client_id,
'Content-Type': 'application/json'
},
form: {
'hub.callback':
this.config.callbackUrl + '?item.id=' + item.id,
'hub.mode': 'unsubscribe',
'hub.topic': item.topic,
'hub.secret': item.secret
},
json: true
});
this.logger.debug('WebSub unsubscribed: ' + id);
} else {
this.logger.warn('Unable to find subscription with id ' + id);
}
} catch (err) {
throw err;
}
};
/**
* Destroy the WebSub, unsubscribing every active subscription.
*/
TwitchWebSub.prototype.destroy = async function() {
try {
this.logger.info('Destroying TwitchWebSub...');
for (const key in this.subscribersMap) {
if (this.subscribersMap.hasOwnProperty(key)) {
let item = this.subscribersMap[key];
this.logger.debug(
'Unsubscribing user with topic: ' + item.topic
);
await this.unsubscribe(item.id);
}
}
this.subscribersMap = {};
this.logger.info('TwitchWebSub destroyed.');
} catch (err) {
throw err;
}
};
util.inherits(TwitchWebSub, eventemitter);
module.exports = TwitchWebSub;