build: Flatten project structure

This change updates the project structure to become flattened. 
Previously, the simulator, frontend and API each lived into their own directory. 

With this change, all modules of the project live in the top-level directory of 
the repository.

7 files changed, 415 insertions, 0 deletions

diff --git a/opendc-web/opendc-web-api/opendc/util/__init__.py b/opendc-web/opendc-web-api/opendc/util/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/__init__.py
diff --git a/opendc-web/opendc-web-api/opendc/util/database.py b/opendc-web/opendc-web-api/opendc/util/database.py
new file mode 100644
index 00000000..dd26533d
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/database.py
@@ -0,0 +1,77 @@
+import urllib.parse
+from datetime import datetime
+
+from pymongo import MongoClient
+
+DATETIME_STRING_FORMAT = '%Y-%m-%dT%H:%M:%S'
+CONNECTION_POOL = None
+
+
+class Database:
+    """Object holding functionality for database access."""
+    def __init__(self):
+        self.opendc_db = None
+
+    def initialize_database(self, user, password, database, host):
+        """Initializes the database connection."""
+
+        user = urllib.parse.quote_plus(user)
+        password = urllib.parse.quote_plus(password)
+        database = urllib.parse.quote_plus(database)
+        host = urllib.parse.quote_plus(host)
+
+        client = MongoClient('mongodb://%s:%s@%s/default_db?authSource=%s' % (user, password, host, database))
+        self.opendc_db = client.opendc
+
+    def fetch_one(self, query, collection):
+        """Uses existing mongo connection to return a single (the first) document in a collection matching the given
+        query as a JSON object.
+
+        The query needs to be in json format, i.e.: `{'name': prefab_name}`.
+        """
+        return getattr(self.opendc_db, collection).find_one(query)
+
+    def fetch_all(self, query, collection):
+        """Uses existing mongo connection to return all documents matching a given query, as a list of JSON objects.
+
+        The query needs to be in json format, i.e.: `{'name': prefab_name}`.
+        """
+        cursor = getattr(self.opendc_db, collection).find(query)
+        return list(cursor)
+
+    def insert(self, obj, collection):
+        """Updates an existing object."""
+        bson = getattr(self.opendc_db, collection).insert(obj)
+
+        return bson
+
+    def update(self, _id, obj, collection):
+        """Updates an existing object."""
+        return getattr(self.opendc_db, collection).update({'_id': _id}, obj)
+
+    def delete_one(self, query, collection):
+        """Deletes one object matching the given query.
+
+        The query needs to be in json format, i.e.: `{'name': prefab_name}`.
+        """
+        getattr(self.opendc_db, collection).delete_one(query)
+
+    def delete_all(self, query, collection):
+        """Deletes all objects matching the given query.
+
+        The query needs to be in json format, i.e.: `{'name': prefab_name}`.
+        """
+        getattr(self.opendc_db, collection).delete_many(query)
+
+    @staticmethod
+    def datetime_to_string(datetime_to_convert):
+        """Return a database-compatible string representation of the given datetime object."""
+        return datetime_to_convert.strftime(DATETIME_STRING_FORMAT)
+
+    @staticmethod
+    def string_to_datetime(string_to_convert):
+        """Return a datetime corresponding to the given string representation."""
+        return datetime.strptime(string_to_convert, DATETIME_STRING_FORMAT)
+
+
+DB = Database()
diff --git a/opendc-web/opendc-web-api/opendc/util/exceptions.py b/opendc-web/opendc-web-api/opendc/util/exceptions.py
new file mode 100644
index 00000000..7724a407
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/exceptions.py
@@ -0,0 +1,64 @@
+class RequestInitializationError(Exception):
+    """Raised when a Request cannot successfully be initialized"""
+
+
+class UnimplementedEndpointError(RequestInitializationError):
+    """Raised when a Request path does not point to a module."""
+
+
+class MissingRequestParameterError(RequestInitializationError):
+    """Raised when a Request does not contain one or more required parameters."""
+
+
+class UnsupportedMethodError(RequestInitializationError):
+    """Raised when a Request does not use a supported REST method.
+
+    The method must be in all-caps, supported by REST, and implemented by the module.
+    """
+
+
+class AuthorizationTokenError(RequestInitializationError):
+    """Raised when an authorization token is not correctly verified."""
+
+
+class ForeignKeyError(Exception):
+    """Raised when a foreign key constraint is not met."""
+
+
+class RowNotFoundError(Exception):
+    """Raised when a database row is not found."""
+    def __init__(self, table_name):
+        super(RowNotFoundError, self).__init__('Row in `{}` table not found.'.format(table_name))
+
+        self.table_name = table_name
+
+
+class ParameterError(Exception):
+    """Raised when a parameter is either missing or incorrectly typed."""
+
+
+class IncorrectParameterError(ParameterError):
+    """Raised when a parameter is of the wrong type."""
+    def __init__(self, parameter_name, parameter_location):
+        super(IncorrectParameterError,
+              self).__init__('Incorrectly typed `{}` {} parameter.'.format(parameter_name, parameter_location))
+
+        self.parameter_name = parameter_name
+        self.parameter_location = parameter_location
+
+
+class MissingParameterError(ParameterError):
+    """Raised when a parameter is missing."""
+    def __init__(self, parameter_name, parameter_location):
+        super(MissingParameterError,
+              self).__init__('Missing required `{}` {} parameter.'.format(parameter_name, parameter_location))
+
+        self.parameter_name = parameter_name
+        self.parameter_location = parameter_location
+
+
+class ClientError(Exception):
+    """Raised when a 4xx response is to be returned."""
+    def __init__(self, response):
+        super(ClientError, self).__init__(str(response))
+        self.response = response
diff --git a/opendc-web/opendc-web-api/opendc/util/json.py b/opendc-web/opendc-web-api/opendc/util/json.py
new file mode 100644
index 00000000..2ef4f965
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/json.py
@@ -0,0 +1,12 @@
+import flask
+from bson.objectid import ObjectId
+
+
+class JSONEncoder(flask.json.JSONEncoder):
+    """
+    A customized JSON encoder to handle unsupported types.
+    """
+    def default(self, o):
+        if isinstance(o, ObjectId):
+            return str(o)
+        return flask.json.JSONEncoder.default(self, o)
diff --git a/opendc-web/opendc-web-api/opendc/util/parameter_checker.py b/opendc-web/opendc-web-api/opendc/util/parameter_checker.py
new file mode 100644
index 00000000..14dd1dc0
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/parameter_checker.py
@@ -0,0 +1,85 @@
+from opendc.util import exceptions
+from opendc.util.database import Database
+
+
+def _missing_parameter(params_required, params_actual, parent=''):
+    """Recursively search for the first missing parameter."""
+
+    for param_name in params_required:
+
+        if param_name not in params_actual:
+            return '{}.{}'.format(parent, param_name)
+
+        param_required = params_required.get(param_name)
+        param_actual = params_actual.get(param_name)
+
+        if isinstance(param_required, dict):
+
+            param_missing = _missing_parameter(param_required, param_actual, param_name)
+
+            if param_missing is not None:
+                return '{}.{}'.format(parent, param_missing)
+
+    return None
+
+
+def _incorrect_parameter(params_required, params_actual, parent=''):
+    """Recursively make sure each parameter is of the correct type."""
+
+    for param_name in params_required:
+
+        param_required = params_required.get(param_name)
+        param_actual = params_actual.get(param_name)
+
+        if isinstance(param_required, dict):
+
+            param_incorrect = _incorrect_parameter(param_required, param_actual, param_name)
+
+            if param_incorrect is not None:
+                return '{}.{}'.format(parent, param_incorrect)
+
+        else:
+
+            if param_required == 'datetime':
+                try:
+                    Database.string_to_datetime(param_actual)
+                except:
+                    return '{}.{}'.format(parent, param_name)
+
+            type_pairs = [
+                ('int', (int,)),
+                ('float', (float, int)),
+                ('bool', (bool,)),
+                ('string', (str, int)),
+                ('list', (list,)),
+            ]
+
+            for str_type, actual_types in type_pairs:
+                if param_required == str_type and all(not isinstance(param_actual, t)
+                                                      for t in actual_types):
+                    return '{}.{}'.format(parent, param_name)
+
+    return None
+
+
+def _format_parameter(parameter):
+    """Format the output of a parameter check."""
+
+    parts = parameter.split('.')
+    inner = ['["{}"]'.format(x) for x in parts[2:]]
+    return parts[1] + ''.join(inner)
+
+
+def check(request, **kwargs):
+    """Check if all required parameters are there."""
+
+    for location, params_required in kwargs.items():
+        params_actual = getattr(request, 'params_{}'.format(location))
+
+        missing_parameter = _missing_parameter(params_required, params_actual)
+        if missing_parameter is not None:
+            raise exceptions.MissingParameterError(_format_parameter(missing_parameter), location)
+
+        incorrect_parameter = _incorrect_parameter(params_required, params_actual)
+        if incorrect_parameter is not None:
+            raise exceptions.IncorrectParameterError(_format_parameter(incorrect_parameter), location)
diff --git a/opendc-web/opendc-web-api/opendc/util/path_parser.py b/opendc-web/opendc-web-api/opendc/util/path_parser.py
new file mode 100644
index 00000000..c8452f20
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/path_parser.py
@@ -0,0 +1,36 @@
+import json
+import os
+
+
+def parse(version, endpoint_path):
+    """Map an HTTP endpoint path to an API path"""
+
+    # Get possible paths
+    with open(os.path.join(os.path.dirname(__file__), '..', 'api', '{}', 'paths.json').format(version)) as paths_file:
+        paths = json.load(paths_file)
+
+    # Find API path that matches endpoint_path
+    endpoint_path_parts = endpoint_path.strip('/').split('/')
+    paths_parts = [x.strip('/').split('/') for x in paths if len(x.strip('/').split('/')) == len(endpoint_path_parts)]
+    path = None
+
+    for path_parts in paths_parts:
+        found = True
+        for (endpoint_part, part) in zip(endpoint_path_parts, path_parts):
+            if not part.startswith('{') and endpoint_part != part:
+                found = False
+                break
+        if found:
+            path = path_parts
+
+    if path is None:
+        return None
+
+    # Extract path parameters
+    parameters = {}
+
+    for (name, value) in zip(path, endpoint_path_parts):
+        if name.startswith('{'):
+            parameters[name.strip('{}')] = value
+
+    return '{}/{}'.format(version, '/'.join(path)), parameters
diff --git a/opendc-web/opendc-web-api/opendc/util/rest.py b/opendc-web/opendc-web-api/opendc/util/rest.py
new file mode 100644
index 00000000..c9e98295
--- /dev/null
+++ b/opendc-web/opendc-web-api/opendc/util/rest.py
@@ -0,0 +1,141 @@
+import importlib
+import json
+import os
+
+from oauth2client import client, crypt
+
+from opendc.util import exceptions, parameter_checker
+from opendc.util.exceptions import ClientError
+
+
+class Request:
+    """WebSocket message to REST request mapping."""
+    def __init__(self, message=None):
+        """"Initialize a Request from a socket message."""
+
+        # Get the Request parameters from the message
+
+        if message is None:
+            return
+
+        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'].strip('/')
+
+            module_base = 'opendc.api.{}.endpoint'
+            module_path = self.path.replace('{', '').replace('}', '').replace('/', '.')
+
+            self.module = importlib.import_module(module_base.format(module_path))
+        except ImportError as e:
+            print(e)
+            raise exceptions.UnimplementedEndpointError('Unimplemented endpoint: {}.'.format(self.path))
+
+        # Check the method
+
+        if self.method not 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
+
+        if "OPENDC_FLASK_TESTING" in os.environ:
+            self.google_id = 'test'
+            return
+
+        try:
+            self.google_id = self._verify_token(self.token)
+        except crypt.AppIdentityError as e:
+            raise exceptions.AuthorizationTokenError(e)
+
+    def check_required_parameters(self, **kwargs):
+        """Raise an error if a parameter is missing or of the wrong type."""
+
+        try:
+            parameter_checker.check(self, **kwargs)
+        except exceptions.ParameterError as e:
+            raise ClientError(Response(400, str(e)))
+
+    def process(self):
+        """Process the Request and return a Response."""
+
+        method = getattr(self.module, self.method)
+
+        try:
+            response = method(self)
+        except ClientError as e:
+            e.response.id = self.id
+            return e.response
+
+        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)
+
+    @staticmethod
+    def _verify_token(token):
+        """Return the ID of the signed-in user.
+
+        Or throw an Exception if the token is invalid.
+        """
+
+        try:
+            id_info = client.verify_id_token(token, os.environ['OPENDC_OAUTH_CLIENT_ID'])
+        except Exception as e:
+            print(e)
+            raise crypt.AppIdentityError('Exception caught trying to verify ID token: {}'.format(e))
+
+        if id_info['aud'] != os.environ['OPENDC_OAUTH_CLIENT_ID']:
+            raise crypt.AppIdentityError('Unrecognized client.')
+
+        if id_info['iss'] not in ['accounts.google.com', 'https://accounts.google.com']:
+            raise crypt.AppIdentityError('Wrong issuer.')
+
+        return id_info['sub']
+
+
+class Response:
+    """Response to websocket mapping"""
+    def __init__(self, status_code, status_description, content=None):
+        """Initialize a new Response."""
+
+        self.id = 0
+        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, default=str)