Baileys/src/Socket/messages-recv.ts

import { proto } from '../../WAProto'
import { KEY_BUNDLE_TYPE, MIN_PREKEY_COUNT } from '../Defaults'
import { BaileysEventMap, MessageReceiptType, MessageUserReceipt, SocketConfig, WAMessageStubType } from '../Types'
import { debouncedTimeout, decodeMessageStanza, delay, encodeBigEndian, generateSignalPubKey, getStatusFromReceiptType, normalizeMessageContent, xmppPreKey, xmppSignedPreKey } from '../Utils'
import { makeKeyedMutex, makeMutex } from '../Utils/make-mutex'
import processMessage from '../Utils/process-message'
import { areJidsSameUser, BinaryNode, BinaryNodeAttributes, getAllBinaryNodeChildren, getBinaryNodeChild, getBinaryNodeChildren, isJidGroup, isJidUser, jidDecode, jidEncode, jidNormalizedUser, S_WHATSAPP_NET } from '../WABinary'
import { makeChatsSocket } from './chats'
import { extractGroupMetadata } from './groups'

export const makeMessagesRecvSocket = (config: SocketConfig) => {
	const {
		logger,
		treatCiphertextMessagesAsReal,
		retryRequestDelayMs
	} = config
	const sock = makeChatsSocket(config)
	const {
		ev,
		authState,
		ws,
		onUnexpectedError,
		assertSessions,
		assertingPreKeys,
		sendNode,
		relayMessage,
		sendReceipt,
		resyncMainAppState,
		emitEventsFromMap,
		uploadPreKeys,
	} = sock

	/** this mutex ensures that the notifications (receipts, messages etc.) are processed in order */
	const processingMutex = makeKeyedMutex()

	/** this mutex ensures that each retryRequest will wait for the previous one to finish */
	const retryMutex = makeMutex()

	const appStateSyncTimeout = debouncedTimeout(
		6_000,
		() => ws.readyState === ws.OPEN && resyncMainAppState()
	)

	const msgRetryMap = config.msgRetryCounterMap || { }

	const historyCache = new Set<string>()

	const sendMessageAck = async({ tag, attrs }: BinaryNode, extraAttrs: BinaryNodeAttributes) => {
		const stanza: BinaryNode = {
			tag: 'ack',
			attrs: {
				id: attrs.id,
				to: attrs.from,
				...extraAttrs,
			}
		}
		if(!!attrs.participant) {
			stanza.attrs.participant = attrs.participant
		}

		logger.debug({ recv: attrs, sent: stanza.attrs }, `sent "${tag}" ack`)
		await sendNode(stanza)
	}

	const sendRetryRequest = async(node: BinaryNode) => {
		const msgId = node.attrs.id
		const retryCount = msgRetryMap[msgId] || 1
		if(retryCount >= 5) {
			logger.debug({ retryCount, msgId }, 'reached retry limit, clearing')
			delete msgRetryMap[msgId]
			return
		}

		msgRetryMap[msgId] = retryCount + 1

		const isGroup = !!node.attrs.participant
		const { account, signedPreKey, signedIdentityKey: identityKey } = authState.creds

		const deviceIdentity = proto.ADVSignedDeviceIdentity.encode(account).finish()
		await assertingPreKeys(1, async preKeys => {
			const [keyId] = Object.keys(preKeys)
			const key = preKeys[+keyId]

			const decFrom = node.attrs.from ? jidDecode(node.attrs.from) : undefined
			const receipt: BinaryNode = {
				tag: 'receipt',
				attrs: {
					id: msgId,
					type: 'retry',
					to: isGroup ? node.attrs.from : jidEncode(decFrom!.user, 's.whatsapp.net', decFrom!.device, 0)
				},
				content: [
					{
						tag: 'retry',
						attrs: {
							count: retryCount.toString(),
							id: node.attrs.id,
							t: node.attrs.t,
							v: '1'
						}
					},
					{
						tag: 'registration',
						attrs: { },
						content: encodeBigEndian(authState.creds.registrationId)
					}
				]
			}

			if(node.attrs.recipient) {
				receipt.attrs.recipient = node.attrs.recipient
			}

			if(node.attrs.participant) {
				receipt.attrs.participant = node.attrs.participant
			}

			if(retryCount > 1) {
				const exec = generateSignalPubKey(Buffer.from(KEY_BUNDLE_TYPE)).slice(0, 1)
				const content = receipt.content! as BinaryNode[]
				content.push({
					tag: 'keys',
					attrs: { },
					content: [
						{ tag: 'type', attrs: { }, content: exec },
						{ tag: 'identity', attrs: { }, content: identityKey.public },
						xmppPreKey(key, +keyId),
						xmppSignedPreKey(signedPreKey),
						{ tag: 'device-identity', attrs: { }, content: deviceIdentity }
					]
				})
			}

			await sendNode(receipt)

			logger.info({ msgAttrs: node.attrs, retryCount }, 'sent retry receipt')
		})
	}

	const processMessageLocal = async(msg: proto.IWebMessageInfo) => {
		const meId = authState.creds.me!.id
		// process message and emit events
		const newEvents = await processMessage(
			msg,
			{ historyCache, meId, accountSettings: authState.creds.accountSettings, keyStore: authState.keys, logger, treatCiphertextMessagesAsReal }
		)

		// send ack for history message
		const normalizedContent = !!msg.message ? normalizeMessageContent(msg.message) : undefined
		const isAnyHistoryMsg = !!normalizedContent?.protocolMessage?.historySyncNotification
		if(isAnyHistoryMsg) {
			const jid = jidEncode(jidDecode(msg.key.remoteJid!).user, 'c.us')
			await sendReceipt(jid, undefined, [msg.key.id], 'hist_sync')
			// we only want to sync app state once we've all the history
			// restart the app state sync timeout
			logger.debug('restarting app sync timeout')
			appStateSyncTimeout.start()
		}

		return newEvents
	}

	const handleEncryptNotification = async(node: BinaryNode) => {
		const from = node.attrs.from
		if(from === S_WHATSAPP_NET) {
			const countChild = getBinaryNodeChild(node, 'count')
			const count = +countChild.attrs.value
			const shouldUploadMorePreKeys = count < MIN_PREKEY_COUNT

			logger.debug({ count, shouldUploadMorePreKeys }, 'recv pre-key count')
			if(shouldUploadMorePreKeys) {
				await uploadPreKeys()
			}
		} else {
			const identityNode = getBinaryNodeChild(node, 'identity')
			if(identityNode) {
				logger.info({ jid: from }, 'identity changed')
				// not handling right now
				// signal will override new identity anyway
			} else {
				logger.info({ node }, 'unknown encrypt notification')
			}
		}
	}

	const processNotification = async(node: BinaryNode): Promise<Partial<proto.IWebMessageInfo>> => {
		const result: Partial<proto.IWebMessageInfo> = { }
		const [child] = getAllBinaryNodeChildren(node)

		if(node.attrs.type === 'w:gp2') {
			switch (child?.tag) {
			case 'create':
				const metadata = extractGroupMetadata(child)

				result.messageStubType = WAMessageStubType.GROUP_CREATE
				result.messageStubParameters = [metadata.subject]
				result.key = { participant: metadata.owner }

				ev.emit('chats.upsert', [{
					id: metadata.id,
					name: metadata.subject,
					conversationTimestamp: metadata.creation,
				}])
				ev.emit('groups.upsert', [metadata])
				break
			case 'ephemeral':
			case 'not_ephemeral':
				result.message = {
					protocolMessage: {
						type: proto.ProtocolMessage.ProtocolMessageType.EPHEMERAL_SETTING,
						ephemeralExpiration: +(child.attrs.expiration || 0)
					}
				}
				break
			case 'promote':
			case 'demote':
			case 'remove':
			case 'add':
			case 'leave':
				const stubType = `GROUP_PARTICIPANT_${child.tag!.toUpperCase()}`
				result.messageStubType = WAMessageStubType[stubType]

				const participants = getBinaryNodeChildren(child, 'participant').map(p => p.attrs.jid)
				if(
					participants.length === 1 &&
                        // if recv. "remove" message and sender removed themselves
                        // mark as left
                        areJidsSameUser(participants[0], node.attrs.participant) &&
                        child.tag === 'remove'
				) {
					result.messageStubType = WAMessageStubType.GROUP_PARTICIPANT_LEAVE
				}

				result.messageStubParameters = participants
				break
			case 'subject':
				result.messageStubType = WAMessageStubType.GROUP_CHANGE_SUBJECT
				result.messageStubParameters = [ child.attrs.subject ]
				break
			case 'announcement':
			case 'not_announcement':
				result.messageStubType = WAMessageStubType.GROUP_CHANGE_ANNOUNCE
				result.messageStubParameters = [ (child.tag === 'announcement') ? 'on' : 'off' ]
				break
			case 'locked':
			case 'unlocked':
				result.messageStubType = WAMessageStubType.GROUP_CHANGE_RESTRICT
				result.messageStubParameters = [ (child.tag === 'locked') ? 'on' : 'off' ]
				break

			}
		} else {
			switch (child.tag) {
			case 'devices':
				const devices = getBinaryNodeChildren(child, 'device')
				if(areJidsSameUser(child.attrs.jid, authState.creds!.me!.id)) {
					const deviceJids = devices.map(d => d.attrs.jid)
					logger.info({ deviceJids }, 'got my own devices')
				}

				break
			case 'encrypt':
				handleEncryptNotification(node)
				break
			}
		}

		if(Object.keys(result).length) {
			return result
		}
	}

	const sendMessagesAgain = async(key: proto.IMessageKey, ids: string[]) => {
		const msgs = await Promise.all(
			ids.map(id => (
				config.getMessage({ ...key, id })
			))
		)

		const participant = key.participant || key.remoteJid
		await assertSessions([participant], true)

		if(isJidGroup(key.remoteJid)) {
			await authState.keys.set({ 'sender-key-memory': { [key.remoteJid]: null } })
		}

		logger.debug({ participant }, 'forced new session for retry recp')

		for(let i = 0; i < msgs.length;i++) {
			if(msgs[i]) {
				await relayMessage(key.remoteJid, msgs[i], {
					messageId: ids[i],
					participant
				})
			} else {
				logger.debug({ jid: key.remoteJid, id: ids[i] }, 'recv retry request, but message not available')
			}
		}
	}

	const handleReceipt = async(node: BinaryNode) => {
		let shouldAck = true

		const { attrs, content } = node
		const isNodeFromMe = areJidsSameUser(attrs.participant || attrs.from, authState.creds.me?.id)
		const remoteJid = !isNodeFromMe || isJidGroup(attrs.from) ? attrs.from : attrs.recipient
		const fromMe = !attrs.recipient || (attrs.type === 'retry' && isNodeFromMe)

		const ids = [attrs.id]
		if(Array.isArray(content)) {
			const items = getBinaryNodeChildren(content[0], 'item')
			ids.push(...items.map(i => i.attrs.id))
		}

		const key: proto.IMessageKey = {
			remoteJid,
			id: '',
			fromMe,
			participant: attrs.participant
		}

		await processingMutex.mutex(
			remoteJid,
			async() => {
				const status = getStatusFromReceiptType(attrs.type)
				if(
					typeof status !== 'undefined' &&
					(
					// basically, we only want to know when a message from us has been delivered to/read by the other person
					// or another device of ours has read some messages
						status > proto.WebMessageInfo.WebMessageInfoStatus.DELIVERY_ACK ||
						!isNodeFromMe
					)
				) {
					if(isJidGroup(remoteJid)) {
						const updateKey: keyof MessageUserReceipt = status === proto.WebMessageInfo.WebMessageInfoStatus.DELIVERY_ACK ? 'receiptTimestamp' : 'readTimestamp'
						ev.emit(
							'message-receipt.update',
							ids.map(id => ({
								key: { ...key, id },
								receipt: {
									userJid: jidNormalizedUser(attrs.participant),
									[updateKey]: +attrs.t
								}
							}))
						)
					} else {
						ev.emit(
							'messages.update',
							ids.map(id => ({
								key: { ...key, id },
								update: { status }
							}))
						)
					}

				}

				if(attrs.type === 'retry') {
					// correctly set who is asking for the retry
					key.participant = key.participant || attrs.from
					if(key.fromMe) {
						try {
							logger.debug({ attrs, key }, 'recv retry request')
							await sendMessagesAgain(key, ids)
						} catch(error) {
							logger.error({ key, ids, trace: error.stack }, 'error in sending message again')
							shouldAck = false
						}
					} else {
						logger.info({ attrs, key }, 'recv retry for not fromMe message')
					}
				}

				if(shouldAck) {
					await sendMessageAck(node, { class: 'receipt', type: attrs.type })
				}
			}
		)
	}

	const handleNotification = async(node: BinaryNode) => {
		const remoteJid = node.attrs.from
		await sendMessageAck(node, { class: 'notification', type: node.attrs.type })
		await processingMutex.mutex(
			remoteJid,
			async() => {
				const msg = await processNotification(node)
				if(msg) {
					const fromMe = areJidsSameUser(node.attrs.participant || node.attrs.from, authState.creds.me!.id)
					msg.key = {
						remoteJid: node.attrs.from,
						fromMe,
						participant: node.attrs.participant,
						id: node.attrs.id,
						...(msg.key || {})
					}
					msg.participant = node.attrs.participant
					msg.messageTimestamp = +node.attrs.t

					const fullMsg = proto.WebMessageInfo.fromObject(msg)
					ev.emit('messages.upsert', { messages: [fullMsg], type: 'append' })
				}
			}
		)
	}

	const handleUpsertedMessages = async({ messages, type }: BaileysEventMap<any>['messages.upsert']) => {
		if(type === 'notify' || type === 'append') {
			const contactNameUpdates: { [_: string]: string } = { }
			for(const msg of messages) {
				const normalizedChatId = jidNormalizedUser(msg.key.remoteJid)
				if(!!msg.pushName) {
					let jid = msg.key.fromMe ? authState.creds.me!.id : (msg.key.participant || msg.key.remoteJid)
					jid = jidNormalizedUser(jid)

					contactNameUpdates[jid] = msg.pushName
					// update our pushname too
					if(msg.key.fromMe && authState.creds.me?.name !== msg.pushName) {
						ev.emit('creds.update', { me: { ...authState.creds.me!, name: msg.pushName! } })
					}
				}

				const events = await processingMutex.mutex(
					'p-' + normalizedChatId,
					() => processMessageLocal(msg)
				)
				emitEventsFromMap(events)
			}

			if(Object.keys(contactNameUpdates).length) {
				ev.emit('contacts.update', Object.keys(contactNameUpdates).map(
					id => ({ id, notify: contactNameUpdates[id] })
				))
			}
		}
	}

	// recv a message
	ws.on('CB:message', (stanza: BinaryNode) => {
		const { fullMessage: msg, category, author, decryptionTask } = decodeMessageStanza(stanza, authState)
		processingMutex.mutex(
			msg.key.remoteJid!,
			async() => {
				await decryptionTask
				// message failed to decrypt
				if(msg.messageStubType === proto.WebMessageInfo.WebMessageInfoStubType.CIPHERTEXT) {
					logger.error(
						{ msgId: msg.key.id, params: msg.messageStubParameters },
						'failure in decrypting message'
					)
					retryMutex.mutex(
						async() => {
							if(ws.readyState === ws.OPEN) {
								await sendRetryRequest(stanza)
								if(retryRequestDelayMs) {
									await delay(retryRequestDelayMs)
								}
							} else {
								logger.debug({ stanza }, 'connection closed, ignoring retry req')
							}
						}
					)
				} else {
					await sendMessageAck(stanza, { class: 'receipt' })
					// no type in the receipt => message delivered
					let type: MessageReceiptType = undefined
					let participant = msg.key.participant
					if(category === 'peer') { // special peer message
						type = 'peer_msg'
					} else if(msg.key.fromMe) { // message was sent by us from a different device
						type = 'sender'
						// need to specially handle this case
						if(isJidUser(msg.key.remoteJid)) {
							participant = author
						}
					}

					await sendReceipt(msg.key.remoteJid!, participant, [msg.key.id!], type)
				}

				msg.key.remoteJid = jidNormalizedUser(msg.key.remoteJid!)
				ev.emit('messages.upsert', { messages: [msg], type: stanza.attrs.offline ? 'append' : 'notify' })
			}
		)
			.catch(
				error => onUnexpectedError(error, 'processing message')
			)
	})

	ws.on('CB:ack,class:message', async(node: BinaryNode) => {
		sendNode({
			tag: 'ack',
			attrs: {
				class: 'receipt',
				id: node.attrs.id,
				from: node.attrs.from
			}
		})
			.catch(err => onUnexpectedError(err, 'ack message receipt'))
		logger.debug({ attrs: node.attrs }, 'sending receipt for ack')
	})

	ws.on('CB:call', async(node: BinaryNode) => {
		logger.info({ node }, 'recv call')

		const [child] = getAllBinaryNodeChildren(node)
		if(!!child?.tag) {
			sendMessageAck(node, { class: 'call', type: child.tag })
				.catch(
					error => onUnexpectedError(error, 'ack call')
				)
		}
	})

	ws.on('CB:receipt', node => {
		handleReceipt(node)
			.catch(
				error => onUnexpectedError(error, 'handling receipt')
			)
	})

	ws.on('CB:notification', async(node: BinaryNode) => {
		handleNotification(node)
			.catch(
				error => {
					onUnexpectedError(error, 'handling notification')
				}
			)
	})

	ev.on('messages.upsert', data => {
		handleUpsertedMessages(data)
			.catch(
				error => onUnexpectedError(error, 'handling upserted messages')
			)
	})

	return {
		...sock,
		processMessage: processMessageLocal,
		sendMessageAck,
		sendRetryRequest
	}
}