#!/usr/bin/python

import os
import sys
import argparse
import datetime
import time
import hashlib
import base64
import configobj

from i2p import samclasses
from i2p import socket

# parse command line options
parser = argparse.ArgumentParser(
		description='Hosts checker for py-i2phosts.',
		epilog='Report bugs to http://zzz.i2p/topics/733')
parser.add_argument('-d', '--debug', action='store_true',
		help='write debug messages to stdout'),
parser.add_argument('-c', '--config', default='/etc/py-i2phosts/checker.conf', dest='config_file',
		help='config file to use')
args = parser.parse_args()

# read config
config = configobj.ConfigObj(args.config_file)
if 'include' in config:
	config_included = configobj.ConfigObj(config['include'])
	config.merge(config_included)

# django setup
DJANGO_SETTINGS_MODULE = 'settings'
if 'DJANGO_PROJECT_PATH' in config:
	DJANGO_PROJECT_PATH = config['DJANGO_PROJECT_PATH']
else:
	DJANGO_PROJECT_PATH = os.path.dirname(sys.argv[0]) + '/web'
sys.path.insert(1, DJANGO_PROJECT_PATH)
os.environ['DJANGO_SETTINGS_MODULE'] = DJANGO_SETTINGS_MODULE
from web.postkey.models import i2phost
from web.lib.utils import get_logger

# configure logger
if args.debug == True:
	log_level = 'debug'
	log_file = None
else:
	log_level = config['log_level']
	log_file = config['log_file']
log = get_logger(filename=log_file, log_level=log_level)

all_hosts = i2phost.objects.all()

# determine SAM interface address
if 'sam_addr' in config:
	sam_addr = config['sam_addr']
else:
	log.warning('SAM address isn\'t specified in config, falling back to localhost')
	sam_addr = '127.0.0.1:7656'
S = samclasses.BaseSession(sam_addr)

log.info('starting check')
for host in all_hosts:
	log.debug('testing %s', host.name)
	# get b32 address from full dest key
	dest = host.b64hash
	raw_key = base64.b64decode(dest.encode('utf-8'), '-~')
	hash = hashlib.sha256(raw_key)
	b32dest = base64.b32encode(hash.digest()).lower().replace('=', '')+'.b32.i2p'
	# do name lookup query with b32 address
	# it success only if host is alive
	try:
		a = S._namelookup(b32dest)
	except socket.NetworkError, e:
		log.debug('%s: %s', host.name, e.args[0][0])
		continue
	log.info('alive host: %s', host.name)
	# update lastseen timestamp
	host.last_seen = datetime.datetime.now()
	host.save()
S.close()