#!/usr/bin/env python

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

################################################################################

#

#  Rattail -- Retail Software Framework

#  Copyright © 2010-2012 Lance Edgar

#

#  This file is part of Rattail.

#

#  Rattail 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.

#

#  Rattail 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 Rattail.  If not, see <http://www.gnu.org/licenses/>.

#

################################################################################

"""

``rattail.wince`` -- Windows CE App Interface

"""

import os

import os.path

import edbob

from rattail import files

from rattail.csvutil import DictWriter

def collect_batch(path, device='Default'):

    """

    This function is meant to be invoked by the file monitor.  Its purpose is

    to gather handheld scan batch files from arbitrary device-specific folders,

    and move them to yet another ("upstream") folder so that they may be part

    of a single processing queue.  Rather than moving the file as-is, the

    following processing is done on the file:

    Since the Rattail CE app saves the batch contents using a somewhat "binary"

    format, the raw file is parsed (with :func:`parse_batch_file()`) and a

    proper CSV file is written with the "translated" contents.  This file is

    then copied to the collection folder.

    The filename used for the final destination path is also manipulated.

    Instead of using the original filename, one is generated which contains the

    original filename, plus the "device name" and the timestamp of the original

    file.  The ``device`` parameter is used to determine the device name.

    """

    queue = edbob.config.require('rattail.wince', 'collection_dir')

    ctime = files.creation_time(path)

    final_path = os.path.join(queue, '%s,%s,%s.csv' % (

            device,

            ctime.strftime('%Y-%m-%d %H-%M-%S'),

            os.path.basename(path)))

    csv_path = edbob.temp_path(prefix='rattail.', suffix='.csv')

    csv_file = open(csv_path, 'wb')

    writer = DictWriter(csv_file, ['upc', 'cases', 'units'])

    writer.writeheader()

    for upc, cases, units in parse_batch_file(path):

        writer.writerow({

                'upc': upc,

                'cases': cases,

                'units': units,

                })

    csv_file.close()

    files.locking_copy(csv_path, final_path)

def parse_batch_file(path, progress=None):

    """

    Generator which parses a scan batch file originating from the Rattail CE

    application.

    When a valid record is encountered, it is returned as a tuple of the form

    ``(scancode, cases, units)``.

    """

    scancode = None

    cases = None

    units = None

    prog = None

    if progress:

        prog = progress("Parsing scan batch file", files.count_lines(path))

    i = 1

    f = open(path, 'rb')

    line = f.readline()

    while len(line):

        line = line.replace('\x00', '')

        line = line.rstrip('\n')

        if scancode is None:

            scancode = line

        elif cases is None:

            line = line.strip()

            if line and line.isdigit():

                cases = int(line)

            else:

                cases = 0

        elif units is None:

            line = line.strip()

            if line and line.isdigit():

                units = int(line)

            else:

                units = 0

            yield scancode, cases, units

            scancode = None

            cases = None

            units = None

        if prog:

            prog.update(i)

        i += 1

        line = f.readline()

    f.close()

    if prog:

        prog.destroy()