Chatbot working on Browser and Bun

twitch.js

export class Twitch {
	#event = new EventTarget
	on(...data) {
		this.#event.addEventListener(...data)
	}
	removeListener(...data) {
		this.#event.removeEventListener(...data)
	}

	#capabilities = []

	#username
	get username() {
		return this.#username
	}
	#password

	#channels = []
	get channels() {
		return this.#channels
	}
	join(channel) {
		if (!this.#channels.includes(channel))
			return this.ws.send(`JOIN #${channel}`)
	}
	leave(channel) {
		if (this.#channels.includes(channel))
			return this.ws.send(`PART #${channel}`)
	}

	send(channel, message, id) {
		if (this.#channels.includes(channel))
			this.ws.send(`PRIVMSG #${channel} :${message}`)
			// this.ws.send(`@reply-parent-msg-id=${id} PRIVMSG #${channel} :${message}`)
	}

	constructor(options) {
		this.debug = options.debug

		// TODO: Only store username and password, if one missing switch to anonymous mode

		if (!('username' in options))
			options.username = `justinfan${(''+Math.random()).slice(2)}`
		else if (typeof options.username !== 'string')
			return console.error('username must be a string')
		this.#username = options.username

		if ('password' in options)
			this.#password = options.password
		
		if ('capabilities' in options && options.capabilities instanceof Array) {
			for (const capability of options.capabilities)
				if (typeof capability === 'string')
					this.#capabilities.push(capability)
			this.on('CAP', e => e.detail.arguments === '* ACK' && (this.#capabilities = e.detail.parameters.split(' ').map(s => s.slice(10))))
		}

		this.on('PING', e => this.ws.send(`PONG :${e.detail.parameters}`) || this.debug && console.log('PONG', e.detail.parameters))

		this.on('JOIN', e => {
			console.log(e)
			if (e.detail.source === this.#username)
				return this.#channels.push(e.detail.channel)
		})

		this.on('PART', e => {
			if (e.detail.source === this.#username)
				return this.#channels.splice(this.#channels.indexOf(e.detail.channel), 1)
		})

		this.#connect()
	}

	#authorize() {
		this.ws.send(`CAP REQ :${this.#capabilities.map(cap => `twitch.tv/${cap}`).join(' ')}`)
		if (this.#password)
			this.ws.send(`PASS oauth:${this.#password}`)
		this.ws.send(`NICK ${this.#username}`)
		for (const channel of this.#channels)
			this.join(channel)
	}

	#connect() {
		this.ws = Object.assign(new WebSocket('wss://irc-ws.chat.twitch.tv'), {
			onopen: e => this.#authorize(),
			onmessage: e => {
				if (this.debug)
					console.log(e.data)
				for (const message of e.data.matchAll(/(?:@(.+?) )?(?::(?:(.+?)[!@.])?.*tmi\.twitch\.tv )?(?:(.+?) )(?:([^#]+?)[ =]{1,3})?(?:#([^:].+?))? ?(?::(.+))?(?=\r\n|$)/g)) {
					const detail = {}
					if (message[1]) {
						detail.tags = {}
						for (const tag of message[1].matchAll(/(.+?)=([^;]*)(?:;|$)/g))
							tag[2] && (detail.tags[tag[1]] = tag[2])
					}
					if (message[2])
						detail.source = message[2]
					if (message[4])
						detail.arguments = message[4]
					if (message[5])
						detail.channel = message[5]
					if (message[6])
						detail.parameters = message[6]
					this.#event.dispatchEvent(new CustomEvent(message[3], {'detail': detail}))
				}
			},
			// TODO: Handle disconnection
			onclose: e => {
				console.log('close', e)
				// this.ws = this.#connect()
			},
			onerror: e => {
				console.log('error', e)
			}
		})
	}
}

export class Auth {
	#client_id
	#scopes = []

	#_token
	get #token() {
		return this.#_token || (this.#_token = localStorage.getItem(`twitch_token:${this.#client_id}`))
	}
	set #token(token) {
		localStorage[token ? 'setItem' : 'removeItem'](`twitch_token:${this.#client_id}`, this.#_token = token)
	}
	#checkToken() {
		return this.validateToken(this.#token)?.then(r => r || (this.#token = undefined))
	}
	validateToken = token => token && fetch('https://id.twitch.tv/oauth2/validate', {
		headers: {
			authorization: `Bearer ${token}`
		}
	}).then(r => r.ok && r.json()).then(r => r && (r.token = token) && r)

	async implicit() {
		let token = await this.#checkToken()
		if (token)
			return token
		else if (token = new URLSearchParams(window.location.hash.slice(1)).get('access_token'))
			return history.replaceState(null, '', window.location.pathname) || this.validateToken(this.#token = token)
		else
			location.href = `https://id.twitch.tv/oauth2/authorize?response_type=token&redirect_uri=${window.origin}&client_id=${this.#client_id}&scope=${this.#scopes.join('+')}`
	}

	constructor(options) {
		if (!('client_id' in options))
			return console.error('client_id is required')
		else if (typeof options.client_id !== 'string')
			return console.error('client_id must be a string')
		this.#client_id = options.client_id

		if (!('scopes' in options))
			return console.error('scopes are required')
		else if (!(options.scopes instanceof Array))
			return console.error('scopes must be an array of strings')
		for (const scope of options.scopes)
			if (typeof scope === 'string')
				this.#scopes.push(scope)
	}
}

https://dev.twitch.tv/docs/irc/

new Auth({
	client_id: 'changeme', // https://dev.twitch.tv/console
	scopes: [
		'chat:read',
		'chat:edit'
	]
}).implicit().then(r => {
	const client = new Twitch({
		debug: true,
		username: r.login,
		password: r.token,
		capabilities: [
			'commands',
			'membership',
			'tags'
		]
	})
	
	client.on('001', e => client.join('feelfreetoffee'))
	client.on('JOIN', e => client.send(e.detail.channel, 'Hello World!'))

	client.on('PRIVMSG', console.log)
})