weboob-devel/weboob/tools/captcha/virtkeyboard.py

# -*- coding: utf-8 -*-

# Copyright(C) 2011  Pierre Mazière
#
# This file is part of weboob.
#
# weboob is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# weboob 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with weboob. If not, see <http://www.gnu.org/licenses/>.


import hashlib
import Image


class VirtKeyboardError(Exception):
    def __init__(self, msg):
        Exception.__init__(self, msg)


class VirtKeyboard(object):
    def __init__(self, file, coords, color):
        # file: virtual keyboard image
        # coords: dictionary <value to return>:<tuple(x1,y1,x2,y2)>
        # color: color of the symbols in the image
        #        depending on the image, it can be a single value or a tuple
        img = Image.open(file)

        self.bands = img.getbands()
        if isinstance(color, int) and not isinstance(self.bands, str) and len(self.bands) != 1:
            raise VirtKeyboardError("Color requires %i component but only 1 is provided" \
                                    % len(self.bands))
        if not isinstance(color, int) and len(color) != len(self.bands):
            raise VirtKeyboardError("Color requires %i components but %i are provided" \
                                    % (len(self.bands), len(color)))
        self.color = color

        (self.width, self.height) = img.size
        self.pixar = img.load()
        self.coords = {}
        self.md5 = {}
        for i in coords.keys():
            coord = self.get_symbol_coords(coords[i])
            if coord == (-1, -1, -1, -1):
                continue
            self.coords[i] = coord
            self.md5[i] = self.checksum(self.coords[i])

    def get_symbol_coords(self, (x1, y1, x2, y2)):
        newY1 = -1
        newY2 = -1
        for y in range(y1, min(y2 + 1, self.height)):
            empty_line = True
            for x in range(x1, min(x2 + 1, self.width)):
                if self.pixar[x, y] == self.color:
                    empty_line = False
                    if newY1 == -1:
                        newY1 = y
                        break
                    else:
                        break
            if newY1 != -1 and not empty_line:
                newY2 = y
        newX1 = -1
        newX2 = -1
        for x in range(x1, min(x2 + 1, self.width)):
            empty_column = True
            for y in range(y1, min(y2 + 1, self.height)):
                if self.pixar[x, y] == self.color:
                    empty_column = False
                    if newX1 == -1:
                        newX1 = x
                        break
                    else:
                        break
            if newX1 != -1 and not empty_column:
                newX2 = x
        return (newX1, newY1, newX2, newY2)

    def checksum(self, (x1, y1, x2, y2)):
        s = ''
        for y in range(y1, min(y2 + 1, self.height)):
            for x in range(x1, min(x2 + 1, self.width)):
                if self.pixar[x, y] == self.color:
                    s += "."
                else:
                    s += " "
        return hashlib.md5(s).hexdigest()

    def get_symbol_code(self, md5sum):
        for i in self.md5.keys():
            if md5sum == self.md5[i]:
                return i
        raise VirtKeyboardError('Symbol not found')

    def check_symbols(self, symbols, dirname):
        # symbols: dictionary <symbol>:<md5 value>
        for s in symbols.keys():
            try:
                self.get_symbol_code(symbols[s])
            except VirtKeyboardError:
                self.generate_MD5(dirname)
                raise VirtKeyboardError("Symbol '%s' not found; all symbol hashes are available in %s"\
                                        % (s, dirname))

    def generate_MD5(self, dir):
        for i in self.coords.keys():
            width = self.coords[i][2] - self.coords[i][0] + 1
            height = self.coords[i][3] - self.coords[i][1] + 1
            img = Image.new(''.join(self.bands), (width, height))
            matrix = img.load()
            for y in range(height):
                for x in range(width):
                    matrix[x, y] = self.pixar[self.coords[i][0] + x, self.coords[i][1] + y]
            img.save(dir + "/" + self.md5[i] + ".png")


class MappedVirtKeyboard(VirtKeyboard):
    def __init__(self, file, document, img_element, color, map_attr="onclick"):
        map_id = img_element.attrib.get("usemap")[1:]
        map = document.find("//map[@id='" + map_id + "']")
        if map is None:
            map = document.find("//map[@name='" + map_id + "']")

        coords = {}
        for area in map.getiterator("area"):
            code = area.attrib.get(map_attr)
            area_coords = []
            for coord in area.attrib.get("coords").split(','):
                area_coords.append(int(coord))
            coords[code] = tuple(area_coords)

        VirtKeyboard.__init__(self, file, coords, color)