class Stats:
	received=0
	sent=0
	exchangedNodes=0
	transferredBlocks=0


def logReceived(data):
	Stats.received+=len(data)


def logSent(data):
	Stats.sent+=len(data)


def logExchangedNode(k=1):
	Stats.exchangedNodes+=k


def logTransferredBlock():
	Stats.transferredBlocks+=1


def report():
	return """received {rf} ({r:,} B)
sent {sf} ({s:,} B)
exchanged {nodes:,} hash tree nodes
transferred {blocks:,} blocks""".format(rf=formatBytes(Stats.received), r=Stats.received, sf=formatBytes(Stats.sent), s=Stats.sent, nodes=Stats.exchangedNodes, blocks=Stats.transferredBlocks)


def formatBytes(x):
	exts=["B","kiB","MiB","GiB","TiB","PiB"]
	i=0
	while x>1024:
		x/=1024
		i+=1
	if x>=100: x=round(x)
	elif x>=10: x=round(x,1)
	else: x=round(x,2)
	return "{0} {1}".format(x,exts[i])