#! /usr/bin/env python

# PyKota accounting filter
#
# PyKota - Print Quotas for CUPS
#
# (c) 2003 Jerome Alet <alet@librelogiciel.com>
# You're welcome to redistribute this software under the
# terms of the GNU General Public Licence version 2.0
# or, at your option, any higher version.
#
# You can read the complete GNU GPL in the file COPYING
# which should come along with this software, or visit
# the Free Software Foundation's WEB site http://www.fsf.org
#
# $Id$
#
# $Log$
# Revision 1.6  2003/02/06 22:54:33  jalet
# warnpykota should be ok
#
# Revision 1.5  2003/02/05 22:45:25  jalet
# Forgotten import
#
# Revision 1.4  2003/02/05 22:42:51  jalet
# Typo
#
# Revision 1.3  2003/02/05 22:38:39  jalet
# Typo
#
# Revision 1.2  2003/02/05 22:16:20  jalet
# DEVICE_URI is undefined outside of CUPS, i.e. for normal command line tools
#
# Revision 1.1  2003/02/05 21:28:17  jalet
# Initial import into CVS
#
#
#

import sys
import os

from pykota.tool import PyKotaTool, PyKotaToolError
from pykota import requester

class PyKotaFilter(PyKotaTool) :    
    """Class for the PyKota filter."""
    def __init__(self, username) :
        PyKotaTool.__init__(self, isfilter=1)
        self.username = username
        self.requester = requester.openRequester(self.config, self.printername)
        self.printerhostname = self.getPrinterHostname()
    
    def getPrinterHostname(self) :
        """Returns the printer hostname."""
        device_uri = os.environ.get("DEVICE_URI", "")
        # TODO : check this for more complex urls than ipp://myprinter.dot.com:631/printers/lp
        try :
            (backend, destination) = device_uri.split(":", 1) 
        except ValueError :    
            raise PyKotaToolError, "Invalid DEVICE_URI : %s\n" % device_uri
        while destination.startswith("/") :
            destination = destination[1:]
        return destination.split("/")[0].split(":")[0]
        
    def filterInput(self, inputfile) :
        """Transparent filter."""
        mustclose = 0    
        if inputfile is not None :    
            infile = open(inputfile, "rb")
            mustclose = 1
        else :    
            infile = sys.stdin
        data = infile.read(65536)    
        while data :
            sys.stdout.write(data)
            data = infile.read(65536)
        if mustclose :    
            infile.close()
            
def main() :    
    """Do it, and do it right !"""
    #
    # This is a CUPS filter, so we should act and die like a CUPS filter when needed
    narg = len(sys.argv)
    if narg not in (6, 7) :    
        sys.stderr.write("ERROR: %s job-id user title copies options [file]\n" % sys.argv[0])
        return 1
    elif narg == 7 :    
        # input file
        inputfile = sys.argv[6]
    else :    
        # stdin
        inputfile = None
        
    #    
    # According to CUPS documentation, the username is the third command line argument
    username = sys.argv[2].strip()    
    
    # Initializes the current tool
    tool = PyKotaFilter(username)    
    
    # Get the page counter directly from the printer itself
    counterbeforejob = tool.requester.getPrinterPageCounter(tool.printerhostname) # TODO use printername instead, make them match from CUPS' config files
    
    # Get the last page counter and last username from the Quota Storage backend
    pgc = tool.storage.getPrinterPageCounter(tool.printername)    
    if pgc is None :
        # The printer is unknown from the Quota Storage perspective
        # we let the job pass through, but log a warning message
        tool.logger.log_message("Printer %s not registered in the PyKota system" % tool.printername, "warn")
    else :    
        (lastpagecounter, lastusername) = (pgc["pagecounter"], pgc["lastusername"])
        
        # Update the last page counter and last username in the Quota Storage backend
        # set them to current user and 
        tool.storage.updatePrinterPageCounter(tool.printername, username, counterbeforejob) # TODO : allow or deny users not in quota system, and die cleanly if needed
        
        # Is the current user allowed to print at all ?
        action = tool.warnUserPQuota(username)
        if action == "DENY" :
            # No, just die cleanly
            return 1
            
        # Yes     
        if (lastpagecounter is None) or (lastusername is None) :
            lastusername = username
            lastpagecounter = counterbeforejob
        jobsize = (counterbeforejob - lastpagecounter)    
        if jobsize >= 0:
            tool.storage.updateUserPQuota(lastusername, tool.printername, jobsize)
            tool.warnUserPQuota(lastusername)
        else :    
            tool.logger.log_message("Error in page count value %i for user %s on printer %s" % (jobsize, tool.printername, lastusername), "error")
        
    # pass the job untouched to the underlying layer
    tool.filterInput(inputfile)      
    
    return 0

if __name__ == "__main__" :    
    sys.exit(main() or 0)