serializer.py

try:
    import simplejson as json
except ImportError:
    import json
import uuid
from datetime import date, datetime
from decimal import Decimal

from .exceptions import SerializationError, ImproperlyConfigured
from .compat import string_types


class TextSerializer(object):
    mimetype = "text/plain"

    def loads(self, s):
        return s

    def dumps(self, data):
        if isinstance(data, string_types):
            return data

        raise SerializationError("Cannot serialize %r into text." % data)


class JSONSerializer(object):
    mimetype = "application/json"

    def default(self, data):
        if isinstance(data, (date, datetime)):
            return data.isoformat()
        elif isinstance(data, Decimal):
            return float(data)
        elif isinstance(data, uuid.UUID):
            return str(data)
        raise TypeError("Unable to serialize %r (type: %s)" % (data, type(data)))

    def loads(self, s):
        try:
            return json.loads(s)
        except (ValueError, TypeError) as e:
            raise SerializationError(s, e)

    def dumps(self, data):
        # don't serialize strings
        if isinstance(data, string_types):
            return data

        try:
            return json.dumps(
                data, default=self.default, ensure_ascii=False, separators=(",", ":")
            )
        except (ValueError, TypeError) as e:
            raise SerializationError(data, e)


DEFAULT_SERIALIZERS = {
    JSONSerializer.mimetype: JSONSerializer(),
    TextSerializer.mimetype: TextSerializer(),
}


class Deserializer(object):
    def __init__(self, serializers, default_mimetype="application/json"):
        try:
            self.default = serializers[default_mimetype]
        except KeyError:
            raise ImproperlyConfigured(
                "Cannot find default serializer (%s)" % default_mimetype
            )
        self.serializers = serializers

    def loads(self, s, mimetype=None):
        if not mimetype:
            deserializer = self.default
        else:
            # split out charset
            mimetype, _, _ = mimetype.partition(";")
            try:
                deserializer = self.serializers[mimetype]
            except KeyError:
                raise SerializationError(
                    "Unknown mimetype, unable to deserialize: %s" % mimetype
                )

        return deserializer.loads(s)