Add sources.py

sources.py

@@ -0,0 +1,27 @@
+import abc
+from typing import Callable, List
+
+from decouple import config
+
+from models import Commit
+
+
+class CommitSource(abc.ABC):
+    """A simple abstract class for representing different commit sources generally."""
+
+    @abc.abstractmethod
+    def fetch(self, check_function: Callable) -> List[Commit]:
+        """Fetch commits from the source."""
+        pass
+
+
+class Gitlab(CommitSource):
+    """Serves as the commit source for GitLab."""
+
+    API_KEY_CONSTANT: str = 'GITLAB_API_KEY'
+
+    def __init__(self) -> None:
+        self.__api_key: str = config(self.API_KEY_CONSTANT)
+
+    def fetch(self, check_function: Callable) -> List[Commit]:
+        pass