finalize multi-device

src/Utils/history.ts

@@ -0,0 +1,25 @@
+import { downloadContentFromMessage } from "./messages-media";
+import { proto } from "../../WAProto";
+import { promisify } from 'util'
+import { inflate } from "zlib";
+
+const inflatePromise = promisify(inflate)
+
+export const downloadIfHistory = (message: proto.IMessage) => {
+	if(message.protocolMessage?.historySyncNotification) {
+		return downloadHistory(message.protocolMessage!.historySyncNotification)
+	}
+}
+
+export const downloadHistory = async(msg: proto.IHistorySyncNotification) => {
+	const stream = await downloadContentFromMessage(msg, 'history')
+	let buffer = Buffer.from([])
+	for await(const chunk of stream) {
+		buffer = Buffer.concat([buffer, chunk])
+	}
+	// decompress buffer
+	buffer = await inflatePromise(buffer)
+
+	const syncData = proto.HistorySync.decode(buffer)
+	return syncData
+}