"""

Serialize data to/from JSON

"""

import datetime

from StringIO import StringIO

from django.core.serializers.python import Serializer as PythonSerializer

from django.core.serializers.python import Deserializer as PythonDeserializer

from django.utils import datetime_safe

from django.utils import simplejson

try:

    import decimal

except ImportError:

    from django.utils import _decimal as decimal    # Python 2.3 fallback

class Serializer(PythonSerializer):

    """

    Convert a queryset to JSON.

    """

    internal_use_only = False

    def end_serialization(self):

        self.options.pop('stream', None)

        self.options.pop('fields', None)

        simplejson.dump(self.objects, self.stream, cls=DjangoJSONEncoder, **self.options)

    def getvalue(self):

        if callable(getattr(self.stream, 'getvalue', None)):

            return self.stream.getvalue()

def Deserializer(stream_or_string, **options):

    """

    Deserialize a stream or string of JSON data.

    """

    if isinstance(stream_or_string, basestring):

        stream = StringIO(stream_or_string)

    else:

        stream = stream_or_string

    for obj in PythonDeserializer(simplejson.load(stream)):

        yield obj

class DjangoJSONEncoder(simplejson.JSONEncoder):

    """

    JSONEncoder subclass that knows how to encode date/time and decimal types.

    """

    DATE_FORMAT = "%Y-%m-%d"

    TIME_FORMAT = "%H:%M:%S"

    def default(self, o):

        if isinstance(o, datetime.datetime):

            d = datetime_safe.new_datetime(o)

            return d.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))

        elif isinstance(o, datetime.date):

            d = datetime_safe.new_date(o)

            return d.strftime(self.DATE_FORMAT)

        elif isinstance(o, datetime.time):

            return o.strftime(self.TIME_FORMAT)

        elif isinstance(o, decimal.Decimal):

            return str(o)

        else:

            return super(DjangoJSONEncoder, self).default(o)

# Older, deprecated class name (for backwards compatibility purposes).

DateTimeAwareJSONEncoder = DjangoJSONEncoder