#!/usr/bin/env python

#

# Copyright 2015 Google 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.

"""Common code for converting proto to other formats, such as JSON."""

import base64

import collections

import datetime

import json

import six

from apitools.base.protorpclite import message_types

from apitools.base.protorpclite import messages

from apitools.base.protorpclite import protojson

from apitools.base.py import exceptions

__all__ = [

'CopyProtoMessage',

'JsonToMessage',

'MessageToJson',

'DictToMessage',

'MessageToDict',

'PyValueToMessage',

'MessageToPyValue',

'MessageToRepr',

'GetCustomJsonFieldMapping',

'AddCustomJsonFieldMapping',

'GetCustomJsonEnumMapping',

'AddCustomJsonEnumMapping',

]

_Codec = collections.namedtuple('_Codec', ['encoder', 'decoder'])

CodecResult = collections.namedtuple('CodecResult', ['value', 'complete'])

# TODO(craigcitro): Make these non-global.

_UNRECOGNIZED_FIELD_MAPPINGS = {}

_CUSTOM_MESSAGE_CODECS = {}

_CUSTOM_FIELD_CODECS = {}

_FIELD_TYPE_CODECS = {}

def MapUnrecognizedFields(field_name):

"""Register field_name as a container for unrecognized fields."""

def Register(cls):

_UNRECOGNIZED_FIELD_MAPPINGS[cls] = field_name

return cls

return Register

def RegisterCustomMessageCodec(encoder, decoder):

"""Register a custom encoder/decoder for this message class."""

def Register(cls):

_CUSTOM_MESSAGE_CODECS[cls] = _Codec(encoder=encoder, decoder=decoder)

return cls

return Register

def RegisterCustomFieldCodec(encoder, decoder):

"""Register a custom encoder/decoder for this field."""

def Register(field):

_CUSTOM_FIELD_CODECS[field] = _Codec(encoder=encoder, decoder=decoder)

return field

return Register

def RegisterFieldTypeCodec(encoder, decoder):

"""Register a custom encoder/decoder for all fields of this type."""

def Register(field_type):

_FIELD_TYPE_CODECS[field_type] = _Codec(

encoder=encoder, decoder=decoder)

return field_type

return Register

def CopyProtoMessage(message):

"""Make a deep copy of a message."""

return JsonToMessage(type(message), MessageToJson(message))

def MessageToJson(message, include_fields=None):

"""Convert the given message to JSON."""

result = _ProtoJsonApiTools.Get().encode_message(message)

return _IncludeFields(result, message, include_fields)

def JsonToMessage(message_type, message):

"""Convert the given JSON to a message of type message_type."""

return _ProtoJsonApiTools.Get().decode_message(message_type, message)

# TODO(craigcitro): Do this directly, instead of via JSON.

def DictToMessage(d, message_type):

"""Convert the given dictionary to a message of type message_type."""

return JsonToMessage(message_type, json.dumps(d))

def MessageToDict(message):

"""Convert the given message to a dictionary."""

return json.loads(MessageToJson(message))

def DictToAdditionalPropertyMessage(properties, additional_property_type,

sort_items=False):

"""Convert the given dictionary to an AdditionalProperty message."""

items = properties.items()

if sort_items:

items = sorted(items)

map_ = []

for key, value in items:

map_.append(additional_property_type.AdditionalProperty(

key=key, value=value))

return additional_property_type(additionalProperties=map_)

def PyValueToMessage(message_type, value):

"""Convert the given python value to a message of type message_type."""

return JsonToMessage(message_type, json.dumps(value))

def MessageToPyValue(message):

"""Convert the given message to a python value."""

return json.loads(MessageToJson(message))

def MessageToRepr(msg, multiline=False, **kwargs):

"""Return a repr-style string for a protorpc message.

protorpc.Message.__repr__ does not return anything that could be considered

python code. Adding this function lets us print a protorpc message in such

a way that it could be pasted into code later, and used to compare against

other things.

Args:

msg: protorpc.Message, the message to be repr'd.

multiline: bool, True if the returned string should have each field

assignment on its own line.

**kwargs: {str:str}, Additional flags for how to format the string.

Known **kwargs:

shortstrings: bool, True if all string values should be

truncated at 100 characters, since when mocking the contents

typically don't matter except for IDs, and IDs are usually

less than 100 characters.

no_modules: bool, True if the long module name should not be printed with

each type.

Returns:

str, A string of valid python (assuming the right imports have been made)

that recreates the message passed into this function.

"""

# TODO(jasmuth): craigcitro suggests a pretty-printer from apitools/gen.

indent = kwargs.get('indent', 0)

def IndentKwargs(kwargs):

kwargs = dict(kwargs)

kwargs['indent'] = kwargs.get('indent', 0) + 4

return kwargs

if isinstance(msg, list):

s = '['

for item in msg:

if multiline:

s += '\n' + ' ' * (indent + 4)

s += MessageToRepr(

item, multiline=multiline, **IndentKwargs(kwargs)) + ','

if multiline:

s += '\n' + ' ' * indent

s += ']'

return s

if isinstance(msg, messages.Message):

s = type(msg).__name__ + '('

if not kwargs.get('no_modules'):

s = msg.__module__ + '.' + s

names = sorted([field.name for field in msg.all_fields()])

for name in names:

field = msg.field_by_name(name)

if multiline:

s += '\n' + ' ' * (indent + 4)

value = getattr(msg, field.name)

s += field.name + '=' + MessageToRepr(

value, multiline=multiline, **IndentKwargs(kwargs)) + ','

if multiline:

s += '\n' + ' ' * indent

s += ')'

return s

if isinstance(msg, six.string_types):

if kwargs.get('shortstrings') and len(msg) > 100:

msg = msg[:100]

if isinstance(msg, datetime.datetime):

class SpecialTZInfo(datetime.tzinfo):

def __init__(self, offset):

super(SpecialTZInfo, self).__init__()

self.offset = offset

def __repr__(self):

s = 'TimeZoneOffset(' + repr(self.offset) + ')'

if not kwargs.get('no_modules'):

s = 'apitools.base.protorpclite.util.' + s

return s

msg = datetime.datetime(

msg.year, msg.month, msg.day, msg.hour, msg.minute, msg.second,

msg.microsecond, SpecialTZInfo(msg.tzinfo.utcoffset(0)))

return repr(msg)

def _GetField(message, field_path):

for field in field_path:

if field not in dir(message):

raise KeyError('no field "%s"' % field)

message = getattr(message, field)

return message

def _SetField(dictblob, field_path, value):

for field in field_path[:-1]:

dictblob = dictblob.setdefault(field, {})

dictblob[field_path[-1]] = value

def _IncludeFields(encoded_message, message, include_fields):

"""Add the requested fields to the encoded message."""

if include_fields is None:

return encoded_message

result = json.loads(encoded_message)

for field_name in include_fields:

try:

value = _GetField(message, field_name.split('.'))

nullvalue = None

if isinstance(value, list):

nullvalue = []

except KeyError:

raise exceptions.InvalidDataError(

'No field named %s in message of type %s' % (

field_name, type(message)))

_SetField(result, field_name.split('.'), nullvalue)

return json.dumps(result)

def _GetFieldCodecs(field, attr):

result = [

getattr(_CUSTOM_FIELD_CODECS.get(field), attr, None),

getattr(_FIELD_TYPE_CODECS.get(type(field)), attr, None),

]

return [x for x in result if x is not None]

class _ProtoJsonApiTools(protojson.ProtoJson):

"""JSON encoder used by apitools clients."""

_INSTANCE = None

@classmethod

def Get(cls):

if cls._INSTANCE is None:

cls._INSTANCE = cls()

return cls._INSTANCE

def decode_message(self, message_type, encoded_message):

if message_type in _CUSTOM_MESSAGE_CODECS:

return _CUSTOM_MESSAGE_CODECS[

message_type].decoder(encoded_message)

result = _DecodeCustomFieldNames(message_type, encoded_message)

result = super(_ProtoJsonApiTools, self).decode_message(

message_type, result)

result = _ProcessUnknownEnums(result, encoded_message)

result = _ProcessUnknownMessages(result, encoded_message)

return _DecodeUnknownFields(result, encoded_message)

def decode_field(self, field, value):

"""Decode the given JSON value.

Args:

field: a messages.Field for the field we're decoding.

value: a python value we'd like to decode.

Returns:

A value suitable for assignment to field.

"""

for decoder in _GetFieldCodecs(field, 'decoder'):

result = decoder(field, value)

value = result.value

if result.complete:

return value

if isinstance(field, messages.MessageField):

field_value = self.decode_message(

field.message_type, json.dumps(value))

elif isinstance(field, messages.EnumField):

value = GetCustomJsonEnumMapping(

field.type, json_name=value) or value

try:

field_value = super(

_ProtoJsonApiTools, self).decode_field(field, value)

except messages.DecodeError:

if not isinstance(value, six.string_types):

raise

field_value = None

else:

field_value = super(

_ProtoJsonApiTools, self).decode_field(field, value)

return field_value

def encode_message(self, message):

if isinstance(message, messages.FieldList):

return '[%s]' % (', '.join(self.encode_message(x)

for x in message))

# pylint: disable=unidiomatic-typecheck

if type(message) in _CUSTOM_MESSAGE_CODECS:

return _CUSTOM_MESSAGE_CODECS[type(message)].encoder(message)

message = _EncodeUnknownFields(message)

result = super(_ProtoJsonApiTools, self).encode_message(message)

result = _EncodeCustomFieldNames(message, result)

return json.dumps(json.loads(result), sort_keys=True)

def encode_field(self, field, value):

"""Encode the given value as JSON.

Args:

field: a messages.Field for the field we're encoding.

value: a value for field.

Returns:

A python value suitable for json.dumps.

"""

for encoder in _GetFieldCodecs(field, 'encoder'):

result = encoder(field, value)

value = result.value

if result.complete:

return value

if isinstance(field, messages.EnumField):

if field.repeated:

remapped_value = [GetCustomJsonEnumMapping(

field.type, python_name=e.name) or e.name for e in value]

else:

remapped_value = GetCustomJsonEnumMapping(

field.type, python_name=value.name)

if remapped_value:

return remapped_value

if (isinstance(field, messages.MessageField) and

not isinstance(field, message_types.DateTimeField)):

value = json.loads(self.encode_message(value))

return super(_ProtoJsonApiTools, self).encode_field(field, value)

# TODO(craigcitro): Fold this and _IncludeFields in as codecs.

def _DecodeUnknownFields(message, encoded_message):

"""Rewrite unknown fields in message into message.destination."""

destination = _UNRECOGNIZED_FIELD_MAPPINGS.get(type(message))

if destination is None:

return message

pair_field = message.field_by_name(destination)

if not isinstance(pair_field, messages.MessageField):

raise exceptions.InvalidDataFromServerError(

'Unrecognized fields must be mapped to a compound '

'message type.')

pair_type = pair_field.message_type

# TODO(craigcitro): Add more error checking around the pair

# type being exactly what we suspect (field names, etc).

if isinstance(pair_type.value, messages.MessageField):

new_values = _DecodeUnknownMessages(

message, json.loads(encoded_message), pair_type)

else:

new_values = _DecodeUnrecognizedFields(message, pair_type)

setattr(message, destination, new_values)

# We could probably get away with not setting this, but

# why not clear it?

setattr(message, '_Message__unrecognized_fields', {})

return message

def _DecodeUnknownMessages(message, encoded_message, pair_type):

"""Process unknown fields in encoded_message of a message type."""

field_type = pair_type.value.type

new_values = []

all_field_names = [x.name for x in message.all_fields()]

for name, value_dict in six.iteritems(encoded_message):

if name in all_field_names:

continue

value = PyValueToMessage(field_type, value_dict)

if pair_type.value.repeated:

value = _AsMessageList(value)

new_pair = pair_type(key=name, value=value)

new_values.append(new_pair)

return new_values

def _DecodeUnrecognizedFields(message, pair_type):

"""Process unrecognized fields in message."""

new_values = []

codec = _ProtoJsonApiTools.Get()

for unknown_field in message.all_unrecognized_fields():

# TODO(craigcitro): Consider validating the variant if

# the assignment below doesn't take care of it. It may

# also be necessary to check it in the case that the

# type has multiple encodings.

value, _ = message.get_unrecognized_field_info(unknown_field)

value_type = pair_type.field_by_name('value')

if isinstance(value_type, messages.MessageField):

decoded_value = DictToMessage(value, pair_type.value.message_type)

else:

decoded_value = codec.decode_field(

pair_type.value, value)

try:

new_pair_key = str(unknown_field)

except UnicodeEncodeError:

new_pair_key = protojson.ProtoJson().decode_field(

pair_type.key, unknown_field)

new_pair = pair_type(key=new_pair_key, value=decoded_value)

new_values.append(new_pair)

return new_values

def _CopyProtoMessageVanillaProtoJson(message):

codec = protojson.ProtoJson()

return codec.decode_message(type(message), codec.encode_message(message))

def _EncodeUnknownFields(message):

"""Remap unknown fields in message out of message.source."""

source = _UNRECOGNIZED_FIELD_MAPPINGS.get(type(message))

if source is None:

return message

# CopyProtoMessage uses _ProtoJsonApiTools, which uses this message. Use

# the vanilla protojson-based copy function to avoid infinite recursion.

result = _CopyProtoMessageVanillaProtoJson(message)

pairs_field = message.field_by_name(source)

if not isinstance(pairs_field, messages.MessageField):

raise exceptions.InvalidUserInputError(

'Invalid pairs field %s' % pairs_field)

pairs_type = pairs_field.message_type

value_field = pairs_type.field_by_name('value')

value_variant = value_field.variant

pairs = getattr(message, source)

codec = _ProtoJsonApiTools.Get()

for pair in pairs:

encoded_value = codec.encode_field(value_field, pair.value)

result.set_unrecognized_field(pair.key, encoded_value, value_variant)

setattr(result, source, [])

return result

def _SafeEncodeBytes(field, value):

"""Encode the bytes in value as urlsafe base64."""

try:

if field.repeated:

result = [base64.urlsafe_b64encode(byte) for byte in value]

else:

result = base64.urlsafe_b64encode(value)

complete = True

except TypeError:

result = value

complete = False

return CodecResult(value=result, complete=complete)

def _SafeDecodeBytes(unused_field, value):

"""Decode the urlsafe base64 value into bytes."""

try:

result = base64.urlsafe_b64decode(str(value))

complete = True

except TypeError:

result = value

complete = False

return CodecResult(value=result, complete=complete)

def _ProcessUnknownEnums(message, encoded_message):

"""Add unknown enum values from encoded_message as unknown fields.

ProtoRPC diverges from the usual protocol buffer behavior here and

doesn't allow unknown fields. Throwing on unknown fields makes it

impossible to let servers add new enum values and stay compatible

with older clients, which isn't reasonable for us. We simply store

unrecognized enum values as unknown fields, and all is well.

Args:

message: Proto message we've decoded thus far.

encoded_message: JSON string we're decoding.

Returns:

message, with any unknown enums stored as unrecognized fields.

"""

if not encoded_message:

return message

decoded_message = json.loads(encoded_message)

for field in message.all_fields():

if (isinstance(field, messages.EnumField) and

field.name in decoded_message and

message.get_assigned_value(field.name) is None):

message.set_unrecognized_field(

field.name, decoded_message[field.name], messages.Variant.ENUM)

return message

def _ProcessUnknownMessages(message, encoded_message):

"""Store any remaining unknown fields as strings.

ProtoRPC currently ignores unknown values for which no type can be

determined (and logs a "No variant found" message). For the purposes

of reserializing, this is quite harmful (since it throws away

information). Here we simply add those as unknown fields of type

string (so that they can easily be reserialized).

Args:

message: Proto message we've decoded thus far.

encoded_message: JSON string we're decoding.

Returns:

message, with any remaining unrecognized fields saved.

"""

if not encoded_message:

return message

decoded_message = json.loads(encoded_message)

message_fields = [x.name for x in message.all_fields()] + list(

message.all_unrecognized_fields())

missing_fields = [x for x in decoded_message.keys()

if x not in message_fields]

for field_name in missing_fields:

message.set_unrecognized_field(field_name, decoded_message[field_name],

messages.Variant.STRING)

return message

RegisterFieldTypeCodec(_SafeEncodeBytes, _SafeDecodeBytes)(messages.BytesField)

# Note that these could share a dictionary, since they're keyed by

# distinct types, but it's not really worth it.

_JSON_ENUM_MAPPINGS = {}

_JSON_FIELD_MAPPINGS = {}

def AddCustomJsonEnumMapping(enum_type, python_name, json_name,

package=None): # pylint: disable=unused-argument

"""Add a custom wire encoding for a given enum value.

This is primarily used in generated code, to handle enum values

which happen to be Python keywords.

Args:

enum_type: (messages.Enum) An enum type

python_name: (basestring) Python name for this value.

json_name: (basestring) JSON name to be used on the wire.

package: (NoneType, optional) No effect, exists for legacy compatibility.

"""

if not issubclass(enum_type, messages.Enum):

raise exceptions.TypecheckError(

'Cannot set JSON enum mapping for non-enum "%s"' % enum_type)

if python_name not in enum_type.names():

raise exceptions.InvalidDataError(

'Enum value %s not a value for type %s' % (python_name, enum_type))

field_mappings = _JSON_ENUM_MAPPINGS.setdefault(enum_type, {})

_CheckForExistingMappings('enum', enum_type, python_name, json_name)

field_mappings[python_name] = json_name

def AddCustomJsonFieldMapping(message_type, python_name, json_name,

package=None): # pylint: disable=unused-argument

"""Add a custom wire encoding for a given message field.

This is primarily used in generated code, to handle enum values

which happen to be Python keywords.

Args:

message_type: (messages.Message) A message type

python_name: (basestring) Python name for this value.

json_name: (basestring) JSON name to be used on the wire.

package: (NoneType, optional) No effect, exists for legacy compatibility.

"""

if not issubclass(message_type, messages.Message):

raise exceptions.TypecheckError(

'Cannot set JSON field mapping for '

'non-message "%s"' % message_type)

try:

_ = message_type.field_by_name(python_name)

except KeyError:

raise exceptions.InvalidDataError(

'Field %s not recognized for type %s' % (

python_name, message_type))

field_mappings = _JSON_FIELD_MAPPINGS.setdefault(message_type, {})

_CheckForExistingMappings('field', message_type, python_name, json_name)

field_mappings[python_name] = json_name

def GetCustomJsonEnumMapping(enum_type, python_name=None, json_name=None):

"""Return the appropriate remapping for the given enum, or None."""

return _FetchRemapping(enum_type, 'enum',

python_name=python_name, json_name=json_name,

mappings=_JSON_ENUM_MAPPINGS)

def GetCustomJsonFieldMapping(message_type, python_name=None, json_name=None):

"""Return the appropriate remapping for the given field, or None."""

return _FetchRemapping(message_type, 'field',

python_name=python_name, json_name=json_name,

mappings=_JSON_FIELD_MAPPINGS)

def _FetchRemapping(type_name, mapping_type, python_name=None, json_name=None,

mappings=None):

"""Common code for fetching a key or value from a remapping dict."""

if python_name and json_name:

raise exceptions.InvalidDataError(

'Cannot specify both python_name and json_name '

'for %s remapping' % mapping_type)

if not (python_name or json_name):

raise exceptions.InvalidDataError(

'Must specify either python_name or json_name for %s remapping' % (

mapping_type,))

field_remappings = mappings.get(type_name, {})

if field_remappings:

if python_name:

return field_remappings.get(python_name)

elif json_name:

if json_name in list(field_remappings.values()):

return [k for k in field_remappings

if field_remappings[k] == json_name][0]

return None

def _CheckForExistingMappings(mapping_type, message_type,

python_name, json_name):

"""Validate that no mappings exist for the given values."""

if mapping_type == 'field':

getter = GetCustomJsonFieldMapping

elif mapping_type == 'enum':

getter = GetCustomJsonEnumMapping

remapping = getter(message_type, python_name=python_name)

if remapping is not None and remapping != json_name:

raise exceptions.InvalidDataError(

'Cannot add mapping for %s "%s", already mapped to "%s"' % (

mapping_type, python_name, remapping))

remapping = getter(message_type, json_name=json_name)

if remapping is not None and remapping != python_name:

raise exceptions.InvalidDataError(

'Cannot add mapping for %s "%s", already mapped to "%s"' % (

mapping_type, json_name, remapping))

def _EncodeCustomFieldNames(message, encoded_value):

field_remappings = list(_JSON_FIELD_MAPPINGS.get(type(message), {})

.items())

if field_remappings:

decoded_value = json.loads(encoded_value)

for python_name, json_name in field_remappings:

if python_name in encoded_value:

decoded_value[json_name] = decoded_value.pop(python_name)

encoded_value = json.dumps(decoded_value)

return encoded_value

def _DecodeCustomFieldNames(message_type, encoded_message):

field_remappings = _JSON_FIELD_MAPPINGS.get(message_type, {})

if field_remappings:

decoded_message = json.loads(encoded_message)

for python_name, json_name in list(field_remappings.items()):

if json_name in decoded_message:

decoded_message[python_name] = decoded_message.pop(json_name)

encoded_message = json.dumps(decoded_message)

return encoded_message

def _AsMessageList(msg):

"""Convert the provided list-as-JsonValue to a list."""

# This really needs to live in extra_types, but extra_types needs

# to import this file to be able to register codecs.

# TODO(craigcitro): Split out a codecs module and fix this ugly

# import.

from apitools.base.py import extra_types

def _IsRepeatedJsonValue(msg):

"""Return True if msg is a repeated value as a JsonValue."""

if isinstance(msg, extra_types.JsonArray):

return True

if isinstance(msg, extra_types.JsonValue) and msg.array_value:

return True

return False

if not _IsRepeatedJsonValue(msg):

raise ValueError('invalid argument to _AsMessageList')

if isinstance(msg, extra_types.JsonValue):

msg = msg.array_value

if isinstance(msg, extra_types.JsonArray):

msg = msg.entries

return msg