#
# Author: Dennis Stam
# Date  : 09-04-2009
# Desc. : This class allows you use ranges within the given arguments. Very
#         useful for specifying mutliple hosts. This class extends the
#         OptionParser class.
#
# SVN Info:
#       $Id: AdvancedParser.py 3667 2009-04-15 12:02:04Z dennis $
#       $URL: https://subtrac.sara.nl/hpcv/svn/beowulf/trunk/sara_python_modules/AdvancedParser.py $
#
from optparse import OptionParser
import re
import types

__author__  = "Dennis Stam"
__version__ = ( 1, 1, 0 )

class AdvancedParser(OptionParser):
        """
        This class extends from OptionParser, where the method check_values has been
        overrided.

        In this function a extra parsing is done on the the rest of the arguments. This
        extra parsing is the creating of multiple hostnames from a pattern/range.

        When a user specifies this argument dr-r[15,17-20]n[1-5,10] then this class
        returns 24 hosts. Besides using numbers you can also specify lower cased
        letters from a-z.

        Doctest:
        >>> parser = AdvancedParser()
        >>> parser.return_range('12-15,20')
        [12, 13, 14, 15, '20']

        >>> option, args = parser.parse_args(['dr-r7n[1-5]'])
        >>> print args
        ['dr-r7n1', 'dr-r7n2', 'dr-r7n3', 'dr-r7n4', 'dr-r7n5']
        """

        def parse_letters( self, chars ):
            
            if type( chars ) is not types.ListType and len( chars ) != 2:
                self.error( 'Could not parse range' )

            start   = ord( chars[ 0 ] )
            end     = ord( chars[ 1 ] )
            out     = list()

            if start > 96 and start < 122 and end > 97 and end < 123:
                lrange = range( start, end + 1 )

                for ichar in lrange:
                    out.append( chr( ichar ) )
                
                return out
            else:
                self.error( 'AdvanedParser module only handles letters from a to z ( lower cased )' )

        def return_range(self, string):
                """
                This method uses the given numbers and converts them to ranges. When
                ower cased letters are specified they will be converted to integer 
                ordinal of a one-character string.
                (ie. a = 97, z = 122)

                The ranges will be return as lists
                """
                numbers_chars = list()
                equal_width_length = 0

                if string.find( ',' ) >= 0 and string.find( ',' ) < 1:
                    self.error( 'You cannot start a range with \',\'. Given range: %s' % string )

                if string.find( '-' ) >= 0 and string.find( '-' ) < 1:
                    self.error( 'You cannot start a range with \'-\'. Given range: %s' % string )

                for section in string.split( ',' ):
                    if section.find( '-' ) > 0:
                        if len( section.split( '-' ) ) != 2:
                            self.error( 'A range must be consisted of two values' )
                        
                        chars = section.split( '-' )

                        try:
                            if chars[ 0 ][ 0 ] == '0' or chars[ 1 ][ 0 ]:
                                if len( chars[ 0 ] ) > len( chars[ 1 ] ):
                                    equal_width_length = len( chars[ 0 ] )
                                else:
                                    equal_width_lenght = len( chars[ 1 ] )

                            numbers_chars += range( int( chars[ 0 ] ), int( chars[ 1 ] ) + 1 )
                        except ValueError:
                            numbers_chars += self.parse_letters( chars )

                    else:
                        if equal_width_length != 0 and len( section ) > equal_width_lenght:
                            equal_width_lenght = len( section )
                        numbers_chars.append( section )

                return numbers_chars

        def combine( self, pre, post):
                '''
                This method is used to combine a possibility of a combination
                '''
                if pre == '':
                        return post
                else:
                        return '%s %s' % (pre, post)

        def combinations( self, listin, prefix=''):
                '''
                This method creates from the given ranges all possible combinations
                '''
                outlist = list()

                if len( listin ) > 1:
                        for item in listin[0]:
                                outlist += self.combinations( listin[1:], self.combine( prefix, str( item ) ) )
                else:
                        for item in listin[0]:
                                outlist.append( tuple( self.combine( prefix, str( item ) ).split( ' ') ) )

                return outlist

        def args_parser(self, args):
                '''
                This method checks all given extra arguments for the given ranges between the
                [ and ]
                '''
                findregex = re.compile( r'\[([0-9a-z\-,]+)\]', re.VERBOSE )
                nodenames = list()

                for arg in args:
                        found = findregex.findall( arg )
                        ranges = list()

                        if found:
                                pattern = findregex.sub( '%s', arg )

                                for part in found:
                                        ranges.append( self.return_range( part ) )

                                combs = self.combinations( ranges )

                                for comb in combs:
                                        # Here the %s in the pattern are
                                        # replaced by the correct value
                                        nodenames.append( pattern % comb )
                        else:
                                nodenames.append( arg )

                return nodenames

        def check_values(self, values, args):
                '''
                Here we override the default method in OptionParser to
                enable our extra parsing on the given Arguments
                '''
                return values, self.args_parser( args )

if __name__ == "__main__":
        import doctest
        doctest.testmod()