#
# Copyright (C) 2007 Martin Owens
#
# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
"""
Python barcode renderer for Code39 barcodes. Designed for use with Inkscape.
"""

from Base import Barcode

encoding = {
    '0' : '000110100',
    '1' : '100100001',
    '2' : '001100001',
    '3' : '101100000', 
    '4' : '000110001',
    '5' : '100110000',
    '6' : '001110000',
    '7' : '000100101',
    '8' : '100100100',
    '9' : '001100100',
    'A' : '100001001',
    'B' : '001001001',
    'C' : '101001000',
    'D' : '000011001',
    'E' : '100011000',
    'F' : '001011000',
    'G' : '000001101',
    'H' : '100001100',
    'I' : '001001100',
    'J' : '000011100',
    'K' : '100000011',
    'L' : '001000011',
    'M' : '101000010',
    'N' : '000010011',
    'O' : '100010010',
    'P' : '001010010',
    'Q' : '000000111',
    'R' : '100000110',
    'S' : '001000110',
    'T' : '000010110',
    'U' : '110000001',
    'V' : '011000001',
    'W' : '111000000',
    'X' : '010010001',
    'Y' : '110010000',
    'Z' : '011010000',
    '-' : '010000101',
    '*' : '010010100',
    '+' : '010001010',
    '$' : '010101000',
    '%' : '000101010',
    '/' : '010100010',
    '.' : '110000100',
    ' ' : '011000100',
}

class Code39(Barcode):
    # Convert a text into string binary of black and white markers
    def encode(self, text):
        text       = text.upper()
        self.label = text
        text       = '*' + text + '*'
        result     = ''
        # It isposible for us to encode code39
        # into full ascii, but this feature is
        # not enabled here
        for char in text:
            if not encoding.has_key(char):
                char = '-';

            result = result + encoding[char] + '0';

        # Now we need to encode the code39, best read
        # the code to understand what it's up to:
        encoded = '';
        colour   = '1'; # 1 = Black, 0 = White
        for data in result:
            if data == '1':
                encoded = encoded + colour + colour
            else:
                encoded = encoded + colour
            colour = colour == '1' and '0' or '1'

        self.inclabel = text
        return encoded;