#!/usr/bin/env python3

# Copyright 2014 Brett Slatkin, Pearson Education Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Preamble to mimick book environment
import logging
from pprint import pprint
from sys import stdout as STDOUT


# Example 1
import json

class Serializable(object):
    def __init__(self, *args):
        self.args = args

    def serialize(self):
        return json.dumps({'args': self.args})


# Example 2
class Point2D(Serializable):
    def __init__(self, x, y):
        super().__init__(x, y)
        self.x = x
        self.y = y

    def __repr__(self):
        return 'Point2D(%d, %d)' % (self.x, self.y)

point = Point2D(5, 3)
print('Object:    ', point)
print('Serialized:', point.serialize())


# Example 3
class Deserializable(Serializable):
    @classmethod
    def deserialize(cls, json_data):
        params = json.loads(json_data)
        return cls(*params['args'])


# Example 4
class BetterPoint2D(Deserializable):
    def __init__(self, x, y):
        super().__init__(x, y)
        self.x = x
        self.y = y

    def __repr__(self):
        return 'BetterPoint2D(%d, %d)' % (self.x, self.y)

point = BetterPoint2D(5, 3)
print('Before:    ', point)
data = point.serialize()
print('Serialized:', data)
after = BetterPoint2D.deserialize(data)
print('After:     ', after)


# Example 5
class BetterSerializable(object):
    def __init__(self, *args):
        self.args = args

    def serialize(self):
        return json.dumps({
            'class': self.__class__.__name__,
            'args': self.args,
        })

    def __repr__(self):
        return '%s(%s)' % (
            self.__class__.__name__,
            ', '.join(str(x) for x in self.args))


# Example 6
registry = {}

def register_class(target_class):
    registry[target_class.__name__] = target_class

def deserialize(data):
    params = json.loads(data)
    name = params['class']
    target_class = registry[name]
    return target_class(*params['args'])


# Example 7
class EvenBetterPoint2D(BetterSerializable):
    def __init__(self, x, y):
        super().__init__(x, y)
        self.x = x
        self.y = y

register_class(EvenBetterPoint2D)


# Example 8
point = EvenBetterPoint2D(5, 3)
print('Before:    ', point)
data = point.serialize()
print('Serialized:', data)
after = deserialize(data)
print('After:     ', after)


# Example 9
class Point3D(BetterSerializable):
    def __init__(self, x, y, z):
        super().__init__(x, y, z)
        self.x = x
        self.y = y
        self.z = z

# Forgot to call register_class! Whoops!


# Example 10
try:
    point = Point3D(5, 9, -4)
    data = point.serialize()
    deserialize(data)
except:
    logging.exception('Expected')
else:
    assert False


# Example 11
class Meta(type):
    def __new__(meta, name, bases, class_dict):
        cls = type.__new__(meta, name, bases, class_dict)
        register_class(cls)
        return cls

class RegisteredSerializable(BetterSerializable, metaclass=Meta):
    pass


# Example 12
class Vector3D(RegisteredSerializable):
    def __init__(self, x, y, z):
        super().__init__(x, y, z)
        self.x, self.y, self.z = x, y, z

v3 = Vector3D(10, -7, 3)
print('Before:    ', v3)
data = v3.serialize()
print('Serialized:', data)
print('After:     ', deserialize(data))