#------------------------------------------------------------------------------
# Copyright (c) 2005, Enthought, Inc.
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in enthought/LICENSE.txt and may be redistributed only
# under the conditions described in the aforementioned license.  The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
# Thanks for using Enthought open source!
#
# Author: Enthought, Inc.
# Description: <Enthought naming package component>
#------------------------------------------------------------------------------
""" The base class for all object serializers. """


# Standard library imports.
import logging
from traceback import print_exc
from os.path import splitext
#import cPickle
#import pickle

# Enthought library imports.
import apptools.sweet_pickle as sweet_pickle
from traits.api import HasTraits, Str


# Setup a logger for this module.
logger = logging.getLogger(__name__)


class ObjectSerializer(HasTraits):
    """ The base class for all object serializers. """

    #### 'ObjectSerializer' interface #########################################

    # The file extension recognized by this serializer.
    ext = Str('.pickle')

    ###########################################################################
    # 'ObjectSerializer' interface.
    ###########################################################################

    def can_load(self, path):
        """ Returns True if the serializer can load a file. """

        rest, ext = splitext(path)

        return ext == self.ext

    def load(self, path):
        """ Loads an object from a file. """

        # Unpickle the object.
        f = file(path, 'rb')
        try:
            try:
                 obj = sweet_pickle.load(f)
#                obj = cPickle.load(f)
#                obj = pickle.load(f)
            except Exception, ex:
                print_exc()
                logger.exception( "Failed to load pickle file: %s, %s" % (path, ex))

                raise
        finally:
            f.close()

        return obj

    def can_save(self, obj):
        """ Returns True if the serializer can save an object. """

        return True

    def save(self, path, obj):
        """ Saves an object to a file. """

        if not path.endswith(self.ext):
            actual_path = path + self.ext

        else:
            actual_path = path

        # Pickle the object.
        f = file(actual_path, 'wb')
        try:
            sweet_pickle.dump(obj, f, 1)
#            cPickle.dump(obj, f, 1)
#            pickle.dump(obj, f, 1)
        except Exception, ex:
            logger.exception( "Failed to pickle into file: %s, %s, object:%s"
                % (path, ex, obj))
            print_exc()
        f.close()

        return actual_path

### EOF #######################################################################