#!/usr/bin/python -O
#
# Description:
# ------------
# This is the server-side portion of the Trusted User package
# manager.  This program will receive uploads from its client-side
# couterpart, tupkg.  Once a package is received and verified, it
# is placed in a specified temporary incoming directory where
# a separate script will handle migrating it to the AUR.  For
# more information, see the ../README.txt file.
#
# Python Indentation:
# -------------------
# For a vim: line to be effective, it must be at the end of the
# file.  See the end of the file for more information.

import sys
import socket
import threading
import select
import struct
import cgi
import urllib
import MySQLdb
import MySQLdb.connections
import ConfigParser
import getopt
import os.path
import os
import time
from hashlib import md5

CONFIGFILE = '/etc/tupkgs.conf'

config = ConfigParser.ConfigParser()

class ClientFile:
	def __init__(self, filename, actual_size, actual_md5):
		self.pathname = os.path.join(confdict['incomingdir'], filename)
		self.filename = filename
		self.fd = open(self.pathname, "a+b")
		self.actual_size = actual_size
		self.actual_md5 = actual_md5
		self.getSize()
		self.orig_size = self.size

	def getSize(self):
		cur = self.fd.tell()
		self.fd.seek(0,2)
		self.size = self.fd.tell()
		self.fd.seek(cur)

	def makeMd5(self):
		m = md5();
		cur = self.fd.tell()
		self.getSize()
		self.fd.seek(0)
		while self.fd.tell() != self.size:
			m.update(self.fd.read(1024))
		self.fd.seek(cur)
		self.md5 = m.hexdigest()

	def finishDownload(self):
		self.fd.close()
		newpathname = os.path.join(confdict['cachedir'], self.filename)
		os.rename(self.pathname, newpathname)
		self.pathname = newpathname
		self.fd = open(self.pathname, "a+b")

	def delete(self):
		self.fd.close()
		os.remove(self.pathname)

class ClientSocket(threading.Thread):
	def __init__(self, sock, **other):
		threading.Thread.__init__(self, *other)
		self.socket = sock
		self.running = 1
		self.files = []

	def close(self):
		self.running = 0

	def reliableRead(self, size):
		totalread = ""
		while len(totalread) < size:
			read = self.socket.recv(size-len(totalread))
			if len(read) == 0:
				raise RuntimeError, "socket connection broken"
			totalread += read
		return totalread

	def sendMsg(self, msg):
		if type(msg) == dict:
			msg = urllib.urlencode(msg,1)
		length = struct.pack("H", socket.htons(len(msg)))
		self.socket.sendall(length)
		self.socket.sendall(msg)

	def readMsg(self, format=0):
		initsize = self.reliableRead(2)
		(length,) = struct.unpack("H", initsize)
		length = socket.ntohs(length)
		data = self.reliableRead(length)
		if format == 1:
			qs = cgi.parse_qs(data)
			return qs
		else:
			return data

	def auth(self):
		authdata = self.readMsg(1)

		if (authdata.has_key('username')):
			print "Trying connection for user %s" % authdata['username']

		if (not authdata.has_key('username')) or (not authdata.has_key('password')):
			self.sendMsg("result=FAIL")
			return 0
		
		print "Connecting to MySQL database"
		dbconn = MySQLdb.connect(host=config.get('mysql', 'host'),
				user=config.get('mysql', 'username'),
				passwd=config.get('mysql', 'password'),
				db=config.get('mysql', 'db'))
		
		q = dbconn.cursor()
		m = md5();
		m.update(authdata['password'][0])
		encpw = m.hexdigest()
		try:
			q.execute("SELECT ID, Suspended, AccountTypeID FROM Users WHERE Username = '"+
					      MySQLdb.escape_string(authdata['username'][0])+
								"' AND Passwd = '"+
								MySQLdb.escape_string(encpw)+
								"'")
			dbconn.close()
		except :
			self.sendMsg("result=SQLERR")
			return 0
		if q.rowcount == 0:
			self.sendMsg("result=FAIL")
			return 0
		row = q.fetchone()
		if row[1] != 0:
			self.sendMsg("result=FAIL")
			return 0
		if row[2] not in (2, 3):
			self.sendMsg("result=FAIL")
			return 0
		self.sendMsg("result=PASS")
		return 1

	def readFileMeta(self):
		files = self.readMsg(1)
		print files
		# Actually do file checking, et al
		for i in range(int(files['numpkgs'][0])):
			self.files.append(ClientFile(files['name'+str(i)][0], int(files['size'+str(i)][0]), files['md5sum'+str(i)][0]))
		new_files = files.copy()
		for i in files:
			if i[:4] == 'size':
				clientfile = self.files[int(i[4:])]
				new_files[i] = str(clientfile.orig_size)
			if i[:6] == 'md5sum':
				del new_files[i]
		self.sendMsg(new_files)

	def readFiles(self):
		for i in self.files:
			count = i.orig_size
			while count != i.actual_size:
				if count + 1024 > i.actual_size:
					i.fd.write(self.reliableRead(i.actual_size - count))
					count += i.actual_size - count
				else:
					i.fd.write(self.reliableRead(1024))
					count += 1024
			i.fd.flush()
		reply = {'numpkgs': len(self.files)}
		for i, v in enumerate(self.files):
			v.makeMd5()
			if v.actual_md5 == v.md5:
				reply['md5sum'+str(i)] = "PASS"
				v.finishDownload()
			else:
				reply['md5sum'+str(i)] = "FAIL"
				v.delete()
		self.sendMsg(reply)
		print self.readMsg()

	def run(self):
		try:
			if not self.auth():
				print "Error authenticating."
				self.close()
				return
			self.readFileMeta()
			self.readFiles()
		except RuntimeError, err:
			if err.__str__() == "socket connection broken":
				print "Client disconnected, cleaning up"
				self.close()
				return

class ServerSocket(threading.Thread):
	def __init__(self, port, maxqueue, **other):
		threading.Thread.__init__(self, *other)
		self.running = 1
		self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
		self.socket.bind(('', port))
		self.socket.listen(maxqueue)
		self.clients = []

	def _clean(self, client):
		if not client.isAlive():
			return 0
		return 1

	def close(self):
		self.socket.close()
		self.running = 0

	def run(self):
		while self.running:
			sread, swrite, serror = select.select([self.socket],[self.socket],[self.socket],1)
			if sread:
				(clientsocket, address) = self.socket.accept()
				print time.asctime(time.gmtime())
				print "New connection from " + str(address)
				ct = ClientSocket(clientsocket)
				ct.start()
				self.clients.append(ct)

			self.clients = filter(self._clean, self.clients)
		self.socket.close()
		[x.close() for x in self.clients]
		[x.join() for x in self.clients]

def usage(name):
	print "usage: " + name + " [options]"
	print "options:"
	print "  -c, --config       Specify an alternate config file (default " + CONFIGFILE + ")"

def getDefaultConfig():
	confdict = {}
	confdict['port'] = 1034
	confdict['cachedir'] = '/var/cache/tupkgs/'
	confdict['incomingdir'] = '/var/cache/tupkgs/incomplete/'
	confdict['maxqueue'] = 5

	return confdict


confdict = getDefaultConfig()

def main(argv=None):
	if argv is None:
		argv = sys.argv

	try:
		optlist, args = getopt.getopt(argv[1:], "c:", ["config="])
	except getopt.GetoptError:
		usage(argv[0])
		return 1

	conffile = CONFIGFILE

	for i, k in optlist:
		if i in ('-c', '--config'):
			conffile = k

	if not os.path.isfile(conffile):
		print "Error: cannot access config file ("+conffile+")"
		usage(argv[0])
		return 1

	config.read(conffile)

	running = 1

	print "Parsing config file"
	if config.has_section('tupkgs'):
		if config.has_option('tupkgs', 'port'):
			confdict['port'] = config.getint('tupkgs', 'port')
		if config.has_option('tupkgs', 'maxqueue'):
			confdict['maxqueue'] = config.getint('tupkgs', 'maxqueue')
		if config.has_option('tupkgs', 'cachedir'):
			confdict['cachedir'] = config.get('tupkgs', 'cachedir')
		if config.has_option('tupkgs', 'incomingdir'):
			confdict['incomingdir'] = config.get('tupkgs', 'incomingdir')

	print "Verifying "+confdict['cachedir']+" and "+confdict['incomingdir']+" exist"
	if not os.path.isdir(confdict['cachedir']):
		print "Creating "+confdict['cachedir']
		os.mkdir(confdict['cachedir'], 0755)
	if not os.path.isdir(confdict['incomingdir']):
		print "Creating "+confdict['incomingdir']
		os.mkdir(confdict['incomingdir'], 0755)

	print "Starting ServerSocket"
	servsock = ServerSocket(confdict['port'], confdict['maxqueue'])
	servsock.start()

	try:
		while running:
			# Maybe do stuff here?
			time.sleep(10)
	except KeyboardInterrupt:
		running = 0

	print "Waiting for threads to die"

	servsock.close()

	servsock.join()


	return 0

if __name__ == "__main__":
		sys.exit(main())

# Python Indentation:
# -------------------
# Use tabs not spaces.  If you use vim, the following comment will
# configure it to use tabs.
#
# vim:noet:ts=2 sw=2 ft=python
