def archive_group(groupName, mode="update"):
	log("\nArchiving group '" + groupName + "', mode: " + mode + " , on " + time.strftime("%c"), groupName)
	startTime = time.time()
	msgsArchived = 0
	if mode == "retry":
		#don't archive any messages we already have
		#but try to archive ones that we don't, and may have
		#already attempted to archive
		min = 1
	elif mode == "update":
		#start archiving at the last+1 message message we archived
		mostRecent = 1
		if os.path.exists(groupName):
			oldDir = os.getcwd()
			os.chdir(groupName)
			for file in glob.glob("*.json"):
				if int(file[0:-5]) > mostRecent:
					mostRecent = int(file[0:-5])
			os.chdir(oldDir)
		
		min = mostRecent
	elif mode == "restart":
		#delete all previous archival attempts and archive everything again
		if os.path.exists(groupName):
			shutil.rmtree(groupName)
		min = 1
		
	else:
		print ("You have specified an invalid mode (" + mode + ").")
		print ("Valid modes are:\nupdate - add any new messages to the archive\nretry - attempt to get all messages that are not in the archive\nrestart - delete archive and start from scratch")
		sys.exit()
	
	if not os.path.exists(groupName):
		os.makedirs(groupName)
	max = group_messages_max(groupName)
	for x in range(min,max+1):
		if not os.path.isfile(groupName + '/' + str(x) + ".json"):
			print ("Archiving message " + str(x) + " of " + str(max))
			sucsess = archive_message(groupName, x)
			if sucsess == True:
				msgsArchived = msgsArchived + 1
	
	log("Archive finished, archived " + str(msgsArchived) + ", time taken is " + str(time.time() - startTime) + " seconds", groupName)