'''
manages logging events of the CryptoBox
'''
import sys
import os

class CryptoBoxLogger:
	'''
	handles concrete logging events and prints them e.g. to  a logfile
	'''

	DebugLevels	= {"debug":0, "info":3, "warn":6, "error":9}
	DebugFacilities	= {"file":0}

	def __init__(self, level, facility, name=None, user=None):
		try:
			facility = int(facility)
		except ValueError:
			facility = self.DebugFacilities[facility]
		try:
			level = int(level)
		except ValueError:
			level = self.DebugLevels[level]
		self.debug_level = level
		if facility == self.DebugFacilities["file"]:
			self.logFunc = self.message2file
			if name is not None:
				self.logFile = name
			else:
				self.logFile = '/var/log/cryptobox.log'
			try:
				fsock = open(self.logFile, "a")
				fsock.close()
				# TODO: check before, if this file was owned
				# by someone else than the cryptobox user - in this case,
				# we may not chown it - very baaaad!
				"change ownership of log file"
				if user != None:
					os.chown(self.logFile, user, os.getegid())
				return
			except IOError:
				sys.stderr.write("Unable to open logfile (%s) for writing.\n" % (self.logFile, ))
		else:
			sys.stderr.write("Invalid logging facility: %d.\n" % (facility, ))
		"we will only arrive here, if an error occoured"
		sys.stderr.write("Sorry - bye, bye!\n")
		sys.exit(1)


	def printMessage(self, msg_level, text):
		if msg_level is None:	msg_level = self.DebugLevels["debug"]
		"convert debuglevel from string to int, if necessary"
		try:
			msg_level = int(msg_level)
		except ValueError:
			msg_level = self.DebugLevels[msg_level]
		if msg_level >= self.debug_level:
			self.logFunc("[CryptoBox] - %s\n" % (text, ))
	

	def message2file(self, text):
		try:
			log_sock = open(self.logFile, "a")
			try:
				log_sock.writelines(text)
				log_sock.close()
				return
			except IOError:
				sys.stderr.write(
					"Unable to write messages to logfile (%s).\n" % (self.logFile, ))
		except IOError:
			sys.stderr.write("Unable to open logfile (%s) for writing.\n" % (self.logFile, ))
		"we will only arrive here, if an error occoured"
		sys.stderr.write("Sorry - bye, bye!\n")
		sys.exit(1)