1 files changed, 102 insertions, 0 deletions
diff --git a/opendc-web/opendc-web-api/opendc/database.py b/opendc-web/opendc-web-api/opendc/database.py
new file mode 100644
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+++ b/opendc-web/opendc-web-api/opendc/database.py
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+#  Copyright (c) 2021 AtLarge Research
+#
+#  Permission is hereby granted, free of charge, to any person obtaining a copy
+#  of this software and associated documentation files (the "Software"), to deal
+#  in the Software without restriction, including without limitation the rights
+#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+#  copies of the Software, and to permit persons to whom the Software is
+#  furnished to do so, subject to the following conditions:
+#
+#  The above copyright notice and this permission notice shall be included in all
+#  copies or substantial portions of the Software.
+#
+#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+#  SOFTWARE.
+
+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, db=None):
+        """Initializes the database connection."""
+        self.opendc_db = db
+
+    @classmethod
+    def from_credentials(cls, user, password, database, host):
+        """
+        Construct a database instance from the specified credentials.
+        :param user: The username to connect with.
+        :param password: The password to connect with.
+        :param database: The database name to connect to.
+        :param host: The host to connect to.
+        :return: The database instance.
+        """
+        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))
+        return cls(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)