``rattail.sil`` -- Standard Interchange Language

Please see the `Standard Interchange Language Specifications

<http://productcatalog.gs1us.org/Store/tabid/86/CategoryID/21/List/1/catpageindex/2/Level/a/ProductID/46/Default.aspx>`_

for more information.

import edbob

import rattail

def val(value):

    """

    Returns a string version of ``value``, suitable for inclusion within a data

    row of a SIL batch.  The conversion is done as follows:

    If ``value`` is ``None``, an empty string is returned.

    If it is an integer, it is converted directly to a string (i.e. not

    quoted).

    If it is a string, but contains only digits, it is wrapped in single

    quotes.  If the string contains any apostrophes or commas, it is wrapped in

    single quotes with the apostrophes escaped.  Otherwise it is is returned

    as-is without quoting.

    """

    if value is None:

        return ''

    if isinstance(value, int):

        return str(value)

    if not isinstance(value, basestring):

        value = str(value)

    if value.isdigit():

        return "'%s'" % value

    if value.find("'") > -1 or value.find(',') > -1:

        return "'%s'" % value.replace("'", "''")

    return value

def consume_batch_id():

    """

    Returns the next available batch identifier, incrementing the number to

    preserve uniqueness.

    """

    config = edbob.AppConfigParser('rattail')

    config_path = config.get_user_file('rattail.conf', create=True)

    config.read(config_path)

    batch_id = config.get('rattail.sil', 'next_batch_id', default='')

    if not batch_id.isdigit():

        batch_id = '1'

    batch_id = int(batch_id)

    config.set('rattail.sil', 'next_batch_id', str(batch_id + 1))

    config_file = open(config_path, 'w')

    config.write(config_file)

    config_file.close()

    return '%08u' % batch_id

def write_batch_header(fileobj, H01='HM', H03='RATAIL', **kwargs):

    """

    Writes a SIL batch header string to ``fileobj``.  All keyword arguments

    correspond to the SIL specification for the Batch Header Dictionary.

    If you do not override ``H03`` (Source Identifier), then Rattail will

    provide defaults for ``H02`` (Batch Identifier) and ``H20`` (Software

    Revision) - that is, unless you've supplied those yourself..  If you do

    override ``H03`` then you must also provide values for ``H02`` and ``H20``.

    **Batch Header Dictionary:**

    ====  ====    ====  ===========

    Name  Type    Size  Description

    ====  ====    ====  ===========

    H01   CHAR       2  Batch Type

    H02   CHAR       8  Batch Identifier

    H03   CHAR       6  Source Identifier

    H04   CHAR       6  Destination Identifier

    H05   CHAR      12  Audit File Name

    H06   CHAR      12  Response File Name

    H07   DATE       7  Origin Date

    H08   TIME       4  Origin Time

    H09   DATE       7  Execution (Apply) Date

    H10   DATE       4  Execution (Apply) Time

    H11   DATE       7  Purge Date

    H12   CHAR       6  Action Type

    H13   CHAR      50  Batch Description

    H14   CHAR      30  User Defined

    H15   CHAR      30  User Defined

    H16   CHAR      30  User Defined

    H17   NUMBER     1  Warning Level

    H18   NUMBER     5  Maximum Error Count

    H19   CHAR       7  SIL Level/Revision

    H20   CHAR       4  Software Revision

    H21   CHAR      50  Primary Key

    H22   CHAR     512  System Specific Command

    H23   CHAR       8  Dictionary Revision

    Consult the SIL Specification for more information.

    H02 = kwargs.get('H02')

    H20 = kwargs.get('H20')

    if H03 == 'RATAIL':

        if not H02:

            H02 = consume_batch_id()

        if not H20:

            H20 = rattail.__version__[:4]

    kw = kwargs

    fileobj.write('INSERT INTO HEADER_DCT VALUES\n(' + ','.join((

                val(H01),

                val(H02),

                val(H03),

                val(kw.get('H04')),

                val(kw.get('H05')),

                val(kw.get('H06')),

                val(kw.get('H07')),

                val(kw.get('H08')),

                val(kw.get('H09')),

                val(kw.get('H10')),

                val(kw.get('H11')),

                val(kw.get('H12')),

                val(kw.get('H13')),

                val(kw.get('H14')),

                val(kw.get('H15')),

                val(kw.get('H16')),

                val(kw.get('H17')),

                val(kw.get('H18')),

                val(kw.get('H19')),

                val(H20),

                val(kw.get('H21')),

                val(kw.get('H22')),

                val(kw.get('H23')),

                )) + ');\n')

def write_row(fileobj, row, last=False):

    Writes a SIL row string to ``fileobj``.

    ``row`` should be a sequence of values.  If ``last`` is ``True``, then

    ``';'`` will be used as the statement terminator; otherwise ``','`` is

    used.

    """

    terminator = ';' if last else ','

    fileobj.write('(' + ','.join([val(x) for x in row]) + ')'

                  + terminator + '\n')

# # from pkg_resources import iter_entry_points

# # import rattail

# # from rattail.batch import make_batch, RattailBatchTerminal

# from rattail.batches import RattailBatchTerminal

# # _junctions = None

# # class SILError(Exception):

# #     """

# #     Base class for SIL errors.

# #     """

# #     pass

# # class ElementRequiredError(SILError):

# #     """

# #     Raised when a batch import or export is attempted, but the element list

# #     supplied is missing a required element.

# #     """

# #     def __init__(self, required, using):

# #         self.required = required

# #         self.using = using

# #     def __str__(self):

# #         return "The element list supplied is missing required element '%s': %s" % (

# #             self.required, self.using)

# def default_display(field):

#     Returns the default UI display value for a SIL field, according to the

#     Rattail field map.

#     return RattailBatchTerminal.fieldmap_user[field]

# # def get_available_junctions():

# #     """

# #     Returns a dictionary of available :class:`rattail.BatchJunction` classes,

# #     keyed by entry point name.

# #     """

# #     global _junctions

# #     if _junctions is None:

# #         _junctions = {}

# #         for entry_point in iter_entry_points('rattail.batch_junctions'):

# #             _junctions[entry_point.name] = entry_point.load()

# #     return _junctions

# # def get_junction_display(name):

# #     """

# #     Returns the ``display`` value for a registered

# #     :class:`rattail.BatchJunction` class, given its ``name``.

# #     """

# #     juncs = get_available_junctions()

# #     if name in juncs:

# #         return juncs[name].display

# #     return None