#! /usr/bin/env python
# -*- coding: ISO-8859-15 -*-
#
# pkpgcounter : a generic Page Description Language parser
#
# (c) 2003, 2004, 2005, 2006, 2007 Jerome Alet <alet@librelogiciel.com>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# $Id$
#

"""This modules implements a really minimalist PJL parser."""

import sys

class PJLParserError(Exception):
    """An exception for PJLParser related stuff."""
    def __init__(self, message = ""):
        self.message = message
        Exception.__init__(self, message)
    def __repr__(self):
        return self.message
    __str__ = __repr__
        
class PJLParser :
    """A parser for PJL documents.
    
       Only extracts the PJL SET variables. Ignore other statements.
    """
    def __init__(self, pjljob, debug=0) :
        """Initializes PJL Parser."""
        self.debug = debug
        self.statements = pjljob.replace("\r\n", "\n").split("\n")
        self.default_variables = {}
        self.environment_variables = {}
        self.parsed = 0
        self.parse()
        
    def __str__(self) :    
        """Outputs our variables as a string of text."""
        if not self.parsed :
            return ""
        mybuffer = []
        if self.default_variables :
            mybuffer.append("Default variables :")
            for (k, v) in self.default_variables.items() :
                mybuffer.append("  %s : %s" % (k, v))
        if self.environment_variables :        
            mybuffer.append("Environment variables :")
            for (k, v) in self.environment_variables.items() :
                mybuffer.append("  %s : %s" % (k, v))
        return "\n".join(mybuffer)        
            
    def logdebug(self, message) :    
        """Logs a debug message if needed."""
        if self.debug :
            sys.stderr.write("%s\n" % message)
            
    def cleanvars(self) :        
        """Cleans the variables dictionnaries."""
        for dicname in ("default", "environment") :
            varsdic = getattr(self, "%s_variables" % dicname)
            for (k, v) in varsdic.items() :
                if len(v) == 1 :
                    varsdic[k] = v[0]
        
    def parse(self) :
        """Parses a PJL job."""
        for i in range(len(self.statements)) :
            statement = self.statements[i]
            if statement.startswith("@PJL") :
                parts = statement.split()
                nbparts = len(parts)
                if parts[0] == "@PJL" :
                    # this is a valid PJL statement, but we don't
                    # want to examine all of them...
                    if (nbparts > 2) and (parts[1].upper() in ("SET", "DEFAULT")) :
                        # this is what we are interested in !
                        try :    
                            (varname, value) = "".join(parts[2:]).split("=", 1)
                        except :    
                            self.logdebug("Invalid PJL SET statement [%s]" % repr(statement))
                        else :    
                            # all still looks fine...
                            if parts[1].upper() == "DEFAULT" :
                                varsdic = self.default_variables
                            else :    
                                varsdic = self.environment_variables 
                            variable = varsdic.setdefault(varname.upper(), [])
                            variable.append(value)
                    else :
                        self.logdebug("Ignored PJL statement [%s]" % repr(statement))
                else :
                    self.logdebug("Invalid PJL statement [%s]" % repr(statement))
            else :
                self.logdebug("Invalid PJL statement [%s]" % repr(statement))
        self.cleanvars()
        self.parsed = 1
        
def test() :        
    """Test function."""
    if (len(sys.argv) < 2) or ((not sys.stdin.isatty()) and ("-" not in sys.argv[1:])) :
        sys.argv.append("-")
    for arg in sys.argv[1:] :
        if arg == "-" :
            infile = sys.stdin
            mustclose = 0
        else :    
            infile = open(arg, "rb")
            mustclose = 1
        try :
            parser = PJLParser(infile.read(), debug=1)
        except PJLParserError, msg :    
            sys.stderr.write("ERROR: %s\n" % msg)
            sys.stderr.flush()
        if mustclose :    
            infile.close()
        print str(parser)            
    
if __name__ == "__main__" :    
    test()