account-reconcile/account_statement_base_import/parser/parser.py

# -*- coding: utf-8 -*-
##############################################################################
#
#    Author: Joel Grand-Guillaume
#    Copyright 2011-2012 Camptocamp SA
#
#    This program 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.
#
#    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 Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################
import base64
import csv


def UnicodeDictReader(utf8_data, **kwargs):
    csv_reader = csv.DictReader(utf8_data, **kwargs)
    for row in csv_reader:
        yield dict([(key, unicode(value, 'utf-8')) for key, value in row.iteritems()])

class BankStatementImportParser(object):
    """Abstract class for defining parser for different files and
    format to import in a bank statement"""
    
    
    def __init__(self, parser_name, *args, **kwargs):
        # The name of the parser as it will be called
        self.parser_name = parser_name
        # The result as a list of row
        self.result_row_list = None
        # The file buffer on which to work on
        self.filebuffer = None
        # Concatenate here the global commission taken by the bank/office
        # for this statement.
        self.commission_global_amount = None
           
    @classmethod
    def parser_for(cls, parser_name):
        return False
            
    def _decode_64b_stream(self):
        self.filebuffer = base64.b64decode(self.filebuffer)
        return True
    
    def _format(self, decode_base_64=True, **kwargs):
        if decode_base_64:
            self._decode_64b_stream()
        self._custom_format(kwargs)
        return True

    def _custom_format(self, *args, **kwargs):
        """Implement a method to convert format, encoding and so on before
        starting to work on datas."""
        return NotImplementedError

    
    def _pre(self, *args, **kwargs):
        """Implement a method to make a pre-treatment on datas before parsing 
        them, like concatenate stuff, and so..."""
        return NotImplementedError

    def _validate(self, *args, **kwargs):
        """Implement a method to validate the self.result_row_list instance
        property and raise an error if not valid."""
        return NotImplementedError
        
    def _post(self, *args, **kwargs):
        """Implement a method to make some last changes on the result of parsing
        the datas, like converting dates, computing commission, ... """
        return NotImplementedError
        
    def _parse(self, *args, **kwargs):
        """Implement a method to save the result of parsing self.filebuffer 
        in self.result_row_list instance property. Put the commission global
        amount in the self.commission_global_amount one."""
        return NotImplementedError
        
    def parse(self, filebuffer, *args, **kwargs):
        """This will be the method that will be called by wizard, button and so
        to parse a filebuffer by calling successively all the private method
        that need to be define for each parser.
        Return:
             [] of rows as {'key':value}
             
        Note: The row_list must contain only value that are present in the account.
        bank.statement.line object !!!
        """
        if filebuffer:
            self.filebuffer = filebuffer
        else:
            raise Exception(_('No buffer file given.'))
        self._format(*args, **kwargs)
        self._pre(*args, **kwargs)
        self._parse(*args, **kwargs)
        self._validate(*args, **kwargs)
        self._post(*args, **kwargs)
        return self.result_row_list
               
def itersubclasses(cls, _seen=None):
    """
    itersubclasses(cls)

    Generator over all subclasses of a given class, in depth first order.

    >>> list(itersubclasses(int)) == [bool]
    True
    >>> class A(object): pass
    >>> class B(A): pass
    >>> class C(A): pass
    >>> class D(B,C): pass
    >>> class E(D): pass
    >>> 
    >>> for cls in itersubclasses(A):
    ...     print(cls.__name__)
    B
    D
    E
    C
    >>> # get ALL (new-style) classes currently defined
    >>> [cls.__name__ for cls in itersubclasses(object)] #doctest: +ELLIPSIS
    ['type', ...'tuple', ...]
    """
    if not isinstance(cls, type):
        raise TypeError('itersubclasses must be called with '
                        'new-style classes, not %.100r' % cls)
    if _seen is None: _seen = set()
    try:
        subs = cls.__subclasses__()
    except TypeError: # fails only when cls is type
        subs = cls.__subclasses__(cls)
    for sub in subs:
        if sub not in _seen:
            _seen.add(sub)
            yield sub
            for sub in itersubclasses(sub, _seen):
                yield sub
                        
def new_bank_statement_parser(parser_name, *args, **kwargs):
    for cls in itersubclasses(BankStatementImportParser):
        if cls.parser_for(parser_name):
            return cls(parser_name, *args, **kwargs)
    raise ValueError