#
# Authored by Martin Owens <doctormo@gmail.com>
# Debugged by Ralf Heinecke & Martin Siepmann 2007-09-07
#             Horst Schottky 2010-02-27
#
# 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 Code128/EAN128 barcodes. Designed for use with Inkscape.
"""

from Base import Barcode
import math
import re

codeMap = [
        '11011001100','11001101100','11001100110','10010011000','10010001100',
        '10001001100','10011001000','10011000100','10001100100','11001001000',
        '11001000100','11000100100','10110011100','10011011100','10011001110',
        '10111001100','10011101100','10011100110','11001110010','11001011100',
        '11001001110','11011100100','11001110100','11101101110','11101001100',
        '11100101100','11100100110','11101100100','11100110100','11100110010',
        '11011011000','11011000110','11000110110','10100011000','10001011000',
        '10001000110','10110001000','10001101000','10001100010','11010001000',
        '11000101000','11000100010','10110111000','10110001110','10001101110',
        '10111011000','10111000110','10001110110','11101110110','11010001110',
        '11000101110','11011101000','11011100010','11011101110','11101011000',
        '11101000110','11100010110','11101101000','11101100010','11100011010',
        '11101111010','11001000010','11110001010','10100110000','10100001100',
        '10010110000','10010000110','10000101100','10000100110','10110010000',
        '10110000100','10011010000','10011000010','10000110100','10000110010',
        '11000010010','11001010000','11110111010','11000010100','10001111010',
        '10100111100','10010111100','10010011110','10111100100','10011110100',
        '10011110010','11110100100','11110010100','11110010010','11011011110',
        '11011110110','11110110110','10101111000','10100011110','10001011110',
        '10111101000','10111100010','11110101000','11110100010','10111011110',
        '10111101110','11101011110','11110101110','11010000100','11010010000',
        '11010011100','11000111010','11' ]

def mapExtra(sd, chars):
    result = list(sd)
    for char in chars:
        result.append(chr(char))
    result.append('FNC3')
    result.append('FNC2')
    result.append('SHIFT')
    return result

# The mapExtra method is used to slim down the amount
# of pre code and instead we generate the lists
charAB = list(' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_')
charA = mapExtra(charAB, range(0, 31)) # Offset 64
charB = mapExtra(charAB, range(96, 125)) # Offset -32

class Code128(Barcode):
    """Main barcode object, generates the encoding bits here"""
    def encode(self, text):
        result = ''
        blocks = []
        block  = ''

        # Split up into sections of numbers, or charicters
        # This makes sure that all the charicters are encoded
        # In the best way posible for Code128
        for datum in re.findall(r'(?:(?:\d\d){2,})|(?:^\d\d)|.', text):
            if len(datum) == 1:
                block = block + datum
            else:
                if block:
                    blocks.append(self.bestBlock(block))
                    block = ''
                blocks.append( [ 'C', datum ] )

        if block:
            blocks.append(self.bestBlock(block))
            block = '';

        self.inclabel = text
        return self.encodeBlocks(blocks)

    def bestBlock(self, block):
        # If this has lower case then select B over A
        if block.upper() == block:
            return [ 'A', block ]
        return [ 'B', block ]

    def encodeBlocks(self, blocks):
        total  = 0
        pos    = 0
        encode = '';

        for block in blocks:
            set   = block[0]
            datum = block[1]

            # POS :   0,   1
            # A   : 101, 103
            # B   : 100, 104
            # C   :  99, 105
            num = 0;
            if set == 'A':
                num = 103
            elif set == 'B':
                num = 104
            elif set == 'C':
                num = 105

            i = pos
            if pos:
                num = 204 - num
            else:
                i = 1

            total = total + num * i
            encode = encode + codeMap[num]
            pos = pos + 1

            if set == 'A' or set == 'B':
                chars = charB
                if set == 'A':
                    chars = charA

                for char in datum:
                    total = total + (chars.index(char) * pos)
                    encode = encode + codeMap[chars.index(char)]
                    pos = pos + 1
            else:
                for char in (datum[i:i+2] for i in range(0, len(datum), 2)):
                    total = total + (int(char) * pos)
                    encode = encode + codeMap[int(char)]
                    pos = pos + 1

        checksum = total % 103
        encode = encode + codeMap[checksum]
        encode = encode + codeMap[106]
        encode = encode + codeMap[107]

        return encode