1#!/usr/bin/env python
2#
3# Copyright 2015 Google Inc.
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#     http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""Service registry for apitools."""
18
19import collections
20import logging
21import re
22import textwrap
23
24from apitools.base.py import base_api
25from apitools.gen import util
26
27# We're a code generator. I don't care.
28# pylint:disable=too-many-statements
29
30_MIME_PATTERN_RE = re.compile(r'(?i)[a-z0-9_*-]+/[a-z0-9_*-]+')
31
32
33class ServiceRegistry(object):
34
35    """Registry for service types."""
36
37    def __init__(self, client_info, message_registry, command_registry,
38                 names, root_package, base_files_package,
39                 unelidable_request_methods):
40        self.__client_info = client_info
41        self.__package = client_info.package
42        self.__names = names
43        self.__service_method_info_map = collections.OrderedDict()
44        self.__message_registry = message_registry
45        self.__command_registry = command_registry
46        self.__root_package = root_package
47        self.__base_files_package = base_files_package
48        self.__unelidable_request_methods = unelidable_request_methods
49        self.__all_scopes = set(self.__client_info.scopes)
50
51    def Validate(self):
52        self.__message_registry.Validate()
53
54    @property
55    def scopes(self):
56        return sorted(list(self.__all_scopes))
57
58    def __GetServiceClassName(self, service_name):
59        return self.__names.ClassName(
60            '%sService' % self.__names.ClassName(service_name))
61
62    def __PrintDocstring(self, printer, method_info, method_name, name):
63        """Print a docstring for a service method."""
64        if method_info.description:
65            description = util.CleanDescription(method_info.description)
66            first_line, newline, remaining = method_info.description.partition(
67                '\n')
68            if not first_line.endswith('.'):
69                first_line = '%s.' % first_line
70            description = '%s%s%s' % (first_line, newline, remaining)
71        else:
72            description = '%s method for the %s service.' % (method_name, name)
73        with printer.CommentContext():
74            printer('"""%s' % description)
75        printer()
76        printer('Args:')
77        printer('  request: (%s) input message', method_info.request_type_name)
78        printer('  global_params: (StandardQueryParameters, default: None) '
79                'global arguments')
80        if method_info.upload_config:
81            printer('  upload: (Upload, default: None) If present, upload')
82            printer('      this stream with the request.')
83        if method_info.supports_download:
84            printer(
85                '  download: (Download, default: None) If present, download')
86            printer('      data from the request via this stream.')
87        printer('Returns:')
88        printer('  (%s) The response message.', method_info.response_type_name)
89        printer('"""')
90
91    def __WriteSingleService(
92            self, printer, name, method_info_map, client_class_name):
93        printer()
94        class_name = self.__GetServiceClassName(name)
95        printer('class %s(base_api.BaseApiService):', class_name)
96        with printer.Indent():
97            printer('"""Service class for the %s resource."""', name)
98            printer()
99            printer('_NAME = %s', repr(name))
100
101            # Print the configs for the methods first.
102            printer()
103            printer('def __init__(self, client):')
104            with printer.Indent():
105                printer('super(%s.%s, self).__init__(client)',
106                        client_class_name, class_name)
107                printer('self._upload_configs = {')
108                with printer.Indent(indent='    '):
109                    for method_name, method_info in method_info_map.items():
110                        upload_config = method_info.upload_config
111                        if upload_config is not None:
112                            printer(
113                                "'%s': base_api.ApiUploadInfo(", method_name)
114                            with printer.Indent(indent='    '):
115                                attrs = sorted(
116                                    x.name for x in upload_config.all_fields())
117                                for attr in attrs:
118                                    printer('%s=%r,',
119                                            attr, getattr(upload_config, attr))
120                            printer('),')
121                    printer('}')
122
123            # Now write each method in turn.
124            for method_name, method_info in method_info_map.items():
125                printer()
126                params = ['self', 'request', 'global_params=None']
127                if method_info.upload_config:
128                    params.append('upload=None')
129                if method_info.supports_download:
130                    params.append('download=None')
131                printer('def %s(%s):', method_name, ', '.join(params))
132                with printer.Indent():
133                    self.__PrintDocstring(
134                        printer, method_info, method_name, name)
135                    printer("config = self.GetMethodConfig('%s')", method_name)
136                    upload_config = method_info.upload_config
137                    if upload_config is not None:
138                        printer("upload_config = self.GetUploadConfig('%s')",
139                                method_name)
140                    arg_lines = [
141                        'config, request, global_params=global_params']
142                    if method_info.upload_config:
143                        arg_lines.append(
144                            'upload=upload, upload_config=upload_config')
145                    if method_info.supports_download:
146                        arg_lines.append('download=download')
147                    printer('return self._RunMethod(')
148                    with printer.Indent(indent='    '):
149                        for line in arg_lines[:-1]:
150                            printer('%s,', line)
151                        printer('%s)', arg_lines[-1])
152                printer()
153                printer('{0}.method_config = lambda: base_api.ApiMethodInfo('
154                        .format(method_name))
155                with printer.Indent(indent='    '):
156                    method_info = method_info_map[method_name]
157                    attrs = sorted(
158                        x.name for x in method_info.all_fields())
159                    for attr in attrs:
160                        if attr in ('upload_config', 'description'):
161                            continue
162                        value = getattr(method_info, attr)
163                        if value is not None:
164                            printer('%s=%r,', attr, value)
165                printer(')')
166
167    def __WriteProtoServiceDeclaration(self, printer, name, method_info_map):
168        """Write a single service declaration to a proto file."""
169        printer()
170        printer('service %s {', self.__GetServiceClassName(name))
171        with printer.Indent():
172            for method_name, method_info in method_info_map.items():
173                for line in textwrap.wrap(method_info.description,
174                                          printer.CalculateWidth() - 3):
175                    printer('// %s', line)
176                printer('rpc %s (%s) returns (%s);',
177                        method_name,
178                        method_info.request_type_name,
179                        method_info.response_type_name)
180        printer('}')
181
182    def WriteProtoFile(self, printer):
183        """Write the services in this registry to out as proto."""
184        self.Validate()
185        client_info = self.__client_info
186        printer('// Generated services for %s version %s.',
187                client_info.package, client_info.version)
188        printer()
189        printer('syntax = "proto2";')
190        printer('package %s;', self.__package)
191        printer('import "%s";', client_info.messages_proto_file_name)
192        printer()
193        for name, method_info_map in self.__service_method_info_map.items():
194            self.__WriteProtoServiceDeclaration(printer, name, method_info_map)
195
196    def WriteFile(self, printer):
197        """Write the services in this registry to out."""
198        self.Validate()
199        client_info = self.__client_info
200        printer('"""Generated client library for %s version %s."""',
201                client_info.package, client_info.version)
202        printer('# NOTE: This file is autogenerated and should not be edited '
203                'by hand.')
204        printer('from %s import base_api', self.__base_files_package)
205        if self.__root_package:
206            import_prefix = 'from {0} '.format(self.__root_package)
207        else:
208            import_prefix = ''
209        printer('%simport %s as messages', import_prefix,
210                client_info.messages_rule_name)
211        printer()
212        printer()
213        printer('class %s(base_api.BaseApiClient):',
214                client_info.client_class_name)
215        with printer.Indent():
216            printer(
217                '"""Generated client library for service %s version %s."""',
218                client_info.package, client_info.version)
219            printer()
220            printer('MESSAGES_MODULE = messages')
221            printer('BASE_URL = {0!r}'.format(client_info.base_url))
222            printer()
223            printer('_PACKAGE = {0!r}'.format(client_info.package))
224            printer('_SCOPES = {0!r}'.format(
225                client_info.scopes or
226                ['https://www.googleapis.com/auth/userinfo.email']))
227            printer('_VERSION = {0!r}'.format(client_info.version))
228            printer('_CLIENT_ID = {0!r}'.format(client_info.client_id))
229            printer('_CLIENT_SECRET = {0!r}'.format(client_info.client_secret))
230            printer('_USER_AGENT = {0!r}'.format(client_info.user_agent))
231            printer('_CLIENT_CLASS_NAME = {0!r}'.format(
232                client_info.client_class_name))
233            printer('_URL_VERSION = {0!r}'.format(client_info.url_version))
234            printer('_API_KEY = {0!r}'.format(client_info.api_key))
235            printer()
236            printer("def __init__(self, url='', credentials=None,")
237            with printer.Indent(indent='             '):
238                printer('get_credentials=True, http=None, model=None,')
239                printer('log_request=False, log_response=False,')
240                printer('credentials_args=None, default_global_params=None,')
241                printer('additional_http_headers=None):')
242            with printer.Indent():
243                printer('"""Create a new %s handle."""', client_info.package)
244                printer('url = url or self.BASE_URL')
245                printer(
246                    'super(%s, self).__init__(', client_info.client_class_name)
247                printer('    url, credentials=credentials,')
248                printer('    get_credentials=get_credentials, http=http, '
249                        'model=model,')
250                printer('    log_request=log_request, '
251                        'log_response=log_response,')
252                printer('    credentials_args=credentials_args,')
253                printer('    default_global_params=default_global_params,')
254                printer('    additional_http_headers=additional_http_headers)')
255                for name in self.__service_method_info_map.keys():
256                    printer('self.%s = self.%s(self)',
257                            name, self.__GetServiceClassName(name))
258            for name, method_info in self.__service_method_info_map.items():
259                self.__WriteSingleService(
260                    printer, name, method_info, client_info.client_class_name)
261
262    def __RegisterService(self, service_name, method_info_map):
263        if service_name in self.__service_method_info_map:
264            raise ValueError(
265                'Attempt to re-register descriptor %s' % service_name)
266        self.__service_method_info_map[service_name] = method_info_map
267
268    def __CreateRequestType(self, method_description, body_type=None):
269        """Create a request type for this method."""
270        schema = {}
271        schema['id'] = self.__names.ClassName('%sRequest' % (
272            self.__names.ClassName(method_description['id'], separator='.'),))
273        schema['type'] = 'object'
274        schema['properties'] = collections.OrderedDict()
275        if 'parameterOrder' not in method_description:
276            ordered_parameters = list(method_description.get('parameters', []))
277        else:
278            ordered_parameters = method_description['parameterOrder'][:]
279            for k in method_description['parameters']:
280                if k not in ordered_parameters:
281                    ordered_parameters.append(k)
282        for parameter_name in ordered_parameters:
283            field_name = self.__names.CleanName(parameter_name)
284            field = dict(method_description['parameters'][parameter_name])
285            if 'type' not in field:
286                raise ValueError('No type found in parameter %s' % field)
287            schema['properties'][field_name] = field
288        if body_type is not None:
289            body_field_name = self.__GetRequestField(
290                method_description, body_type)
291            if body_field_name in schema['properties']:
292                raise ValueError('Failed to normalize request resource name')
293            if 'description' not in body_type:
294                body_type['description'] = (
295                    'A %s resource to be passed as the request body.' % (
296                        self.__GetRequestType(body_type),))
297            schema['properties'][body_field_name] = body_type
298        self.__message_registry.AddDescriptorFromSchema(schema['id'], schema)
299        return schema['id']
300
301    def __CreateVoidResponseType(self, method_description):
302        """Create an empty response type."""
303        schema = {}
304        method_name = self.__names.ClassName(
305            method_description['id'], separator='.')
306        schema['id'] = self.__names.ClassName('%sResponse' % method_name)
307        schema['type'] = 'object'
308        schema['description'] = 'An empty %s response.' % method_name
309        self.__message_registry.AddDescriptorFromSchema(schema['id'], schema)
310        return schema['id']
311
312    def __NeedRequestType(self, method_description, request_type):
313        """Determine if this method needs a new request type created."""
314        if not request_type:
315            return True
316        method_id = method_description.get('id', '')
317        if method_id in self.__unelidable_request_methods:
318            return True
319        message = self.__message_registry.LookupDescriptorOrDie(request_type)
320        if message is None:
321            return True
322        field_names = [x.name for x in message.fields]
323        parameters = method_description.get('parameters', {})
324        for param_name, param_info in parameters.items():
325            if (param_info.get('location') != 'path' or
326                    self.__names.CleanName(param_name) not in field_names):
327                break
328        else:
329            return False
330        return True
331
332    def __MaxSizeToInt(self, max_size):
333        """Convert max_size to an int."""
334        size_groups = re.match(r'(?P<size>\d+)(?P<unit>.B)?$', max_size)
335        if size_groups is None:
336            raise ValueError('Could not parse maxSize')
337        size, unit = size_groups.group('size', 'unit')
338        shift = 0
339        if unit is not None:
340            unit_dict = {'KB': 10, 'MB': 20, 'GB': 30, 'TB': 40}
341            shift = unit_dict.get(unit.upper())
342            if shift is None:
343                raise ValueError('Unknown unit %s' % unit)
344        return int(size) * (1 << shift)
345
346    def __ComputeUploadConfig(self, media_upload_config, method_id):
347        """Fill out the upload config for this method."""
348        config = base_api.ApiUploadInfo()
349        if 'maxSize' in media_upload_config:
350            config.max_size = self.__MaxSizeToInt(
351                media_upload_config['maxSize'])
352        if 'accept' not in media_upload_config:
353            logging.warn(
354                'No accept types found for upload configuration in '
355                'method %s, using */*', method_id)
356        config.accept.extend([
357            str(a) for a in media_upload_config.get('accept', '*/*')])
358
359        for accept_pattern in config.accept:
360            if not _MIME_PATTERN_RE.match(accept_pattern):
361                logging.warn('Unexpected MIME type: %s', accept_pattern)
362        protocols = media_upload_config.get('protocols', {})
363        for protocol in ('simple', 'resumable'):
364            media = protocols.get(protocol, {})
365            for attr in ('multipart', 'path'):
366                if attr in media:
367                    setattr(config, '%s_%s' % (protocol, attr), media[attr])
368        return config
369
370    def __ComputeMethodInfo(self, method_description, request, response,
371                            request_field):
372        """Compute the base_api.ApiMethodInfo for this method."""
373        relative_path = self.__names.NormalizeRelativePath(
374            ''.join((self.__client_info.base_path,
375                     method_description['path'])))
376        method_id = method_description['id']
377        ordered_params = []
378        for param_name in method_description.get('parameterOrder', []):
379            param_info = method_description['parameters'][param_name]
380            if param_info.get('required', False):
381                ordered_params.append(param_name)
382        method_info = base_api.ApiMethodInfo(
383            relative_path=relative_path,
384            method_id=method_id,
385            http_method=method_description['httpMethod'],
386            description=util.CleanDescription(
387                method_description.get('description', '')),
388            query_params=[],
389            path_params=[],
390            ordered_params=ordered_params,
391            request_type_name=self.__names.ClassName(request),
392            response_type_name=self.__names.ClassName(response),
393            request_field=request_field,
394        )
395        flat_path = method_description.get('flatPath', None)
396        if flat_path is not None:
397            flat_path = self.__names.NormalizeRelativePath(
398                self.__client_info.base_path + flat_path)
399            if flat_path != relative_path:
400                method_info.flat_path = flat_path
401        if method_description.get('supportsMediaUpload', False):
402            method_info.upload_config = self.__ComputeUploadConfig(
403                method_description.get('mediaUpload'), method_id)
404        method_info.supports_download = method_description.get(
405            'supportsMediaDownload', False)
406        self.__all_scopes.update(method_description.get('scopes', ()))
407        for param, desc in method_description.get('parameters', {}).items():
408            param = self.__names.CleanName(param)
409            location = desc['location']
410            if location == 'query':
411                method_info.query_params.append(param)
412            elif location == 'path':
413                method_info.path_params.append(param)
414            else:
415                raise ValueError(
416                    'Unknown parameter location %s for parameter %s' % (
417                        location, param))
418        method_info.path_params.sort()
419        method_info.query_params.sort()
420        return method_info
421
422    def __BodyFieldName(self, body_type):
423        if body_type is None:
424            return ''
425        return self.__names.FieldName(body_type['$ref'])
426
427    def __GetRequestType(self, body_type):
428        return self.__names.ClassName(body_type.get('$ref'))
429
430    def __GetRequestField(self, method_description, body_type):
431        """Determine the request field for this method."""
432        body_field_name = self.__BodyFieldName(body_type)
433        if body_field_name in method_description.get('parameters', {}):
434            body_field_name = self.__names.FieldName(
435                '%s_resource' % body_field_name)
436        # It's exceedingly unlikely that we'd get two name collisions, which
437        # means it's bound to happen at some point.
438        while body_field_name in method_description.get('parameters', {}):
439            body_field_name = self.__names.FieldName(
440                '%s_body' % body_field_name)
441        return body_field_name
442
443    def AddServiceFromResource(self, service_name, methods):
444        """Add a new service named service_name with the given methods."""
445        method_descriptions = methods.get('methods', {})
446        method_info_map = collections.OrderedDict()
447        items = sorted(method_descriptions.items())
448        for method_name, method_description in items:
449            method_name = self.__names.MethodName(method_name)
450
451            # NOTE: According to the discovery document, if the request or
452            # response is present, it will simply contain a `$ref`.
453            body_type = method_description.get('request')
454            if body_type is None:
455                request_type = None
456            else:
457                request_type = self.__GetRequestType(body_type)
458            if self.__NeedRequestType(method_description, request_type):
459                request = self.__CreateRequestType(
460                    method_description, body_type=body_type)
461                request_field = self.__GetRequestField(
462                    method_description, body_type)
463            else:
464                request = request_type
465                request_field = base_api.REQUEST_IS_BODY
466
467            if 'response' in method_description:
468                response = method_description['response']['$ref']
469            else:
470                response = self.__CreateVoidResponseType(method_description)
471
472            method_info_map[method_name] = self.__ComputeMethodInfo(
473                method_description, request, response, request_field)
474            self.__command_registry.AddCommandForMethod(
475                service_name, method_name, method_info_map[method_name],
476                request, response)
477
478        nested_services = methods.get('resources', {})
479        services = sorted(nested_services.items())
480        for subservice_name, submethods in services:
481            new_service_name = '%s_%s' % (service_name, subservice_name)
482            self.AddServiceFromResource(new_service_name, submethods)
483
484        self.__RegisterService(service_name, method_info_map)
485