Adding basic model serialization and a simple User api

.gitignore

@@ -1,5 +1,6 @@
 instance/
 .idea
+*.iml
 .admin_credentials
 *__pycache__/
 .pytest_cache/

server/atheneum/__init__.py

@@ -77,8 +77,9 @@ def register_blueprints(app: Flask) -> None:
     :param app:
     :return:
     """
-    from atheneum.api import AUTH_BLUEPRINT
+    from atheneum.api import AUTH_BLUEPRINT, USER_BLUEPRINT
     app.register_blueprint(AUTH_BLUEPRINT)
+    app.register_blueprint(USER_BLUEPRINT)
 
 
 atheneum = create_app()  # pylint: disable=C0103

server/atheneum/api/__init__.py

@@ -1,2 +1,3 @@
 """API blueprint exports."""
 from atheneum.api.authentication_api import AUTH_BLUEPRINT
+from atheneum.api.user_api import USER_BLUEPRINT

server/atheneum/api/user_api.py

@@ -0,0 +1,25 @@
+"""User API blueprint and endpoint definitions."""
+from flask import Blueprint, abort
+
+from atheneum.api.decorators import return_json
+from atheneum.api.model import APIResponse
+from atheneum.middleware import authentication_middleware
+from atheneum.service import user_service
+
+USER_BLUEPRINT = Blueprint(
+    name='user', import_name=__name__, url_prefix='/user')
+
+
+@USER_BLUEPRINT.route('/<name>', methods=['GET'])
+@return_json
+@authentication_middleware.require_token_auth
+def get_user(name: str) -> APIResponse:
+    """
+    Get a token for continued authentication.
+
+    :return: A login token for continued authentication
+    """
+    user = user_service.find_by_name(name)
+    if user is not None:
+        return APIResponse(user, 200)
+    return abort(404)

server/atheneum/errors.py

@@ -0,0 +1,20 @@
+"""Error definitions for Atheneum."""
+from typing import Dict
+
+
+class BaseError(RuntimeError):
+    """Atheneum Base Error Class."""
+
+    def __init__(
+            self,
+            message: str = 'Unknown error',
+            extra_fields: Dict[str, str] = None) -> None:
+        """Populate The Error Definition."""
+        super().__init__(message)
+        self.extra_fields = extra_fields
+
+
+class ValidationError(BaseError):
+    """Atheneum Validation Error."""
+
+    pass

server/atheneum/service/serialization_service.py

@@ -0,0 +1,52 @@
+"""Handle Model Serialization."""
+from typing import Dict, Callable, Any, List, Optional, Type
+
+from atheneum import errors
+from atheneum.db import db
+
+
+class BaseSerializer:  # pylint: disable=too-few-public-methods
+    """Base Model serializer."""
+
+    def __init__(self, model: Type[db.Model]) -> None:
+        """Initialize the base serializer."""
+        self._fields: Dict[str, Callable[[db.Model], Any]] = {}
+        self.model = model
+
+    def serialize(self, options: Optional[List[str]]) -> Any:
+        """Convert Model field and factories to dicts."""
+        field_factories = self._serializers()
+        if not options:
+            options = list(field_factories.keys())
+        ret = {}
+        for key in options:
+            if key not in field_factories:
+                raise errors.ValidationError(
+                    'Invalid key: %r. Valid keys: %r.' % (
+                        key, list(sorted(field_factories.keys()))))
+            factory = field_factories[key]
+            ret[key] = factory()
+        return ret
+
+    def _serializers(self) -> Dict[str, Callable[[], Any]]:
+        """Field definitions."""
+        raise NotImplementedError()
+
+
+_model_serializers: Dict[str, Type[BaseSerializer]] = {}
+
+
+def register_serializer(
+        model_name: str, model_serializer: Type[BaseSerializer]) -> None:
+    """Add a model to the serializer mapping."""
+    _model_serializers[model_name] = model_serializer
+
+
+def serialize_model(model_obj: db.Model) -> Any:
+    """Lookup a Model and hand off to the serializer."""
+    try:
+        return _model_serializers[
+            type(model_obj).__name__](model_obj).serialize(None)
+    except KeyError:
+        raise NotImplementedError(
+            '{} has no registered serializers'.format(model_obj.__name__))

server/atheneum/service/user_service.py

@@ -1,15 +1,56 @@
 """Service to handle user operations."""
 import logging
 from datetime import datetime
-from typing import Optional
+from typing import Optional, Dict, Callable, Any
 
 from atheneum.db import db
 from atheneum.model import User
 from atheneum.utility import authentication_utility
+from atheneum.service.serialization_service import (
+    BaseSerializer,
+    register_serializer
+)
 
 LOGGER = logging.getLogger(__name__)
 
 
+class UserSerializer(BaseSerializer):
+    """Serialize User model."""
+
+    def _serializers(self) -> Dict[str, Callable[[], Any]]:
+        """Define the fields and the accompanying serializer factory."""
+        return {
+            'name': self.serialize_name,
+            'creationTime': self.serialize_creation_time,
+            'lastLoginTime': self.serialize_last_login_time,
+            'version': self.serialize_version,
+            'role': self.serialize_role,
+        }
+
+    def serialize_name(self) -> str:
+        """User name."""
+        return self.model.name
+
+    def serialize_creation_time(self) -> datetime:
+        """User creation time."""
+        return self.model.creation_time
+
+    def serialize_last_login_time(self) -> datetime:
+        """User last login time."""
+        return self.model.last_login_time
+
+    def serialize_version(self) -> int:
+        """User version."""
+        return self.model.version
+
+    def serialize_role(self) -> str:
+        """User role."""
+        return self.model.role
+
+
+register_serializer(User.__name__, UserSerializer)
+
+
 def register(name: str, password: str, role: str) -> User:
     """
     Register a new user.

server/atheneum/utility/json_utility.py

@@ -5,6 +5,9 @@ from typing import Any
 import rfc3339
 from flask.json import JSONEncoder
 
+from atheneum.db import db
+from atheneum.service.serialization_service import serialize_model
+
 
 class CustomJSONEncoder(JSONEncoder):
     """Ensure that datetime values are serialized correctly."""
@@ -14,6 +17,8 @@ class CustomJSONEncoder(JSONEncoder):
         try:
             if isinstance(o, date):
                 return rfc3339.format(o)
+            if isinstance(o, db.Model):
+                return serialize_model(o)
             iterable = iter(o)
         except TypeError:
             pass

server/tests/api/test_user_api.py

@@ -0,0 +1,16 @@
+from flask.testing import FlaskClient
+
+from tests.conftest import AuthActions
+
+
+def test_get_user_happy_path(auth: AuthActions, client: FlaskClient):
+    auth.login()
+    auth_header = auth.get_authorization_header_token()
+    result = client.get(
+        '/user/{}'.format(client.application.config['test_username']),
+        headers={
+            auth_header[0]: auth_header[1]
+        })
+    assert result.status_code == 200
+    assert result.json is not None
+    assert result.json['name'] == client.application.config['test_username']