1 files changed, 59 insertions, 0 deletions
diff --git a/api/opendc/models/model.py b/api/opendc/models/model.py
new file mode 100644
index 00000000..bcb833ae
--- /dev/null
+++ b/api/opendc/models/model.py
@@ -0,0 +1,59 @@
+from uuid import uuid4
+
+from opendc.util.database import DB
+from opendc.util.exceptions import ClientError
+from opendc.util.rest import Response
+
+
+class Model:
+    """Base class for all models."""
+
+    collection_name = '<specified in subclasses>'
+
+    @classmethod
+    def from_id(cls, _id):
+        """Fetches the document with given ID from the collection."""
+        return cls(DB.fetch_one({'_id': _id}, cls.collection_name))
+
+    @classmethod
+    def get_all(cls):
+        """Fetches all documents from the collection."""
+        return cls(DB.fetch_all({}, cls.collection_name))
+
+    def __init__(self, obj):
+        self.obj = obj
+
+    def get_id(self):
+        """Returns the ID of the enclosed object."""
+        return str(self.obj['_id'])
+
+    def check_exists(self):
+        """Raises an error if the enclosed object does not exist."""
+        if self.obj is None:
+            raise ClientError(Response(404, 'Not found.'))
+
+    def set_property(self, key, value):
+        """Sets the given property on the enclosed object, with support for simple nested access."""
+        if '.' in key:
+            keys = key.split('.')
+            self.obj[keys[0]][keys[1]] = value
+        else:
+            self.obj[key] = value
+
+    def insert(self):
+        """Inserts the enclosed object and generates a UUID for it."""
+        self.obj['_id'] = str(uuid4())
+        DB.insert(self.obj, self.collection_name)
+
+    def update(self):
+        """Updates the enclosed object and updates the internal reference to the newly inserted object."""
+        DB.update(self.get_id(), self.obj, self.collection_name)
+
+    def delete(self):
+        """Deletes the enclosed object in the database, if it existed."""
+        if self.obj is None:
+            return None
+
+        old_object = self.obj.copy()
+        DB.delete_one({'_id': self.get_id()}, self.collection_name)
+        return old_object