1 files changed, 137 insertions, 0 deletions
diff --git a/opendc/util/rest.py b/opendc/util/rest.py
new file mode 100644
index 00000000..a52b0082
--- /dev/null
+++ b/opendc/util/rest.py
@@ -0,0 +1,137 @@
+import importlib
+import json
+import os
+import sys
+
+from oauth2client import client, crypt
+
+from opendc.util import exceptions, parameter_checker
+
+with open('/var/www/opendc.ewi.tudelft.nl/web-server/config/keys.json') as file:
+    KEYS = json.load(file)
+
+class Request(object):
+    """WebSocket message to REST request mapping."""
+
+    def __init__(self, message):
+        """"Initialize a Request from a socket message."""
+
+        # Get the Request parameters from the message
+
+        try:
+            self.message = message
+            
+            self.id = message['id']
+            
+            self.path = message['path']
+            self.method = message['method']
+            
+            self.params_body = message['parameters']['body']
+            self.params_path = message['parameters']['path']
+            self.params_query = message['parameters']['query']
+            
+            self.token = message['token']
+
+        except KeyError as exception:
+            raise exceptions.MissingRequestParameterError(exception)
+
+        # Parse the path and import the appropriate module
+
+        try: 
+            self.path = message['path'].encode('ascii', 'ignore').strip('/')
+            
+            module_base = 'opendc.api.{}.endpoint'
+            module_path = self.path.translate(None, '{}').replace('/', '.')
+
+            self.module = importlib.import_module(module_base.format(module_path))
+
+        except UnicodeError as e:
+            raise exceptions.UnimplementedEndpointError('Non-ASCII path')
+
+        except ImportError:
+            raise exceptions.UnimplementedEndpointError(
+                'Unimplemented endpoint: {}.'.format(self.path)
+            )
+
+        # Check the method
+
+        if not self.method in ['POST', 'GET', 'PUT', 'PATCH', 'DELETE']:
+            raise exceptions.UnsupportedMethodError('Non-rest method: {}'.format(self.method))
+
+        if not hasattr(self.module, self.method):
+            raise exceptions.UnsupportedMethodError('Unimplemented method at endpoint {}: {}'.format(self.path, self.method))
+
+        # Verify the user
+        
+        try:
+            self.google_id = self._verify_token(self.token)
+
+        except crypt.AppIdentityError as e:
+            raise exceptions.AuthorizationTokenError(e.message)
+
+    def _verify_token(self, token):
+        """Return the ID of the signed-in user.
+        
+        Or throw an Exception if the token is invalid.
+        """
+
+        try:
+            idinfo = client.verify_id_token(token, KEYS['OAUTH_CLIENT_ID'])
+        except Exception as e:
+            raise crypt.AppIdentityError('Exception caught trying to verify ID token: {}'.format(e))
+
+        if idinfo['aud'] != KEYS['OAUTH_CLIENT_ID']:
+            raise crypt.AppIdentityError('Unrecognized client.')
+
+        if idinfo['iss'] not in ['accounts.google.com', 'https://accounts.google.com']:
+             raise crypt.AppIdentityError('Wrong issuer.')
+
+        return idinfo['sub']
+
+    def check_required_parameters(self, **kwargs):
+        """Raise an error if a parameter is missing or of the wrong type."""
+
+        parameter_checker.check(self, **kwargs)
+
+    def process(self):
+        """Process the Request and return a Response."""
+
+        method = getattr(self.module, self.method)
+
+        response = method(self)
+        response.id = self.id
+
+        return response
+
+    def to_JSON(self):
+        """Return a JSON representation of this Request"""
+
+        self.message['id'] = 0
+        self.message['token'] = None
+
+        return json.dumps(self.message)
+
+class Response(object):
+    """Response to websocket mapping"""
+
+    def __init__(self, status_code, status_description, content=None):
+        """Initialize a new Response."""
+
+        self.status = {
+            'code': status_code,
+            'description': status_description
+        }
+        self.content = content
+    
+    def to_JSON(self):
+        """"Return a JSON representation of this Response"""
+
+        data = {
+            'id': self.id,
+            'status': self.status
+        }
+
+        if self.content is not None:
+            data['content'] = self.content
+
+        return json.dumps(data)