# -*- coding: utf-8 -*-

# Modular system for querying game servers.
#
# Author:  Roman Vasiyarov <rvasiyarov@gmail.com>
# License: GPLv3
# $Id$

#
# Savage 2 module
#


import sys
import struct
from datetime import datetime


NAMES = [
	"name",
	"clients",
	"clientsmax",
	"status",
	"map",
	"mapnext",
	"location",
	"playersmin",
	"gametype",
	"version",
	"unk1",
	"unk2",
	"unk3",

	# should be last
	"ping"
]

S2_MAGIC = 0xf197de9a


# not a complete list
unpack_sizes = {
	"B": 1, "b": 1,
	"H": 2, "h": 2,
	"I": 4, "i": 4,
}
def unpack(fmt, data):
	""" wrap struct.unpack() to add null-terminated strings 'z' format
	"""
	t = "<"
	if "!<=>@".find(fmt[0]) != -1:
		t   = fmt[0]
		fmt = fmt[1:]

	out = []
	n   = 0
	for f in fmt:
		if f != "z":
			r = struct.unpack(t + f, data[n:n + unpack_sizes[f]])[0]
			r = int(r)
			n += unpack_sizes[f]
		else:
			r = data[n:].split(b"\0", 1)[0].decode("utf-8")
			n += len(r) + 1
		out.append(r)
	return out


def process(pkt, verbose=False):
	n   = 12  # "header" size
	seq = [None] * 5
	out = ""

	try:
		seq = struct.unpack("<IBHBI", pkt[:n])
	except:
		pass

	try:
		if seq[0] != S2_MAGIC and seq[1] != 0x01 and seq[3] != 0x02:
			raise
		return unpack("<zBBzzzzHzzHII", pkt[n:])
	except:
		return [None] * (len(NAMES) - 1)


def query(sock, servers, verbose = False):
	if not sock or not len(servers):
		return

	info = {}
	pkt  = struct.pack("<I", S2_MAGIC)
	pkt += b"\x01"  # non-reliable
	pkt += struct.pack("<H", 0xffff)
	pkt += b"\x01"  # info command
	pkt += struct.pack("<I", 666)  # just some number

	# send queries
	for sv in servers:
		if verbose:
			sys.stderr.write("sending query to %s...\n" % repr(sv))
		info[sv] = [None, datetime.utcnow()]
		sock.sendto(pkt, 0, sv)

	return info