From 6bc7fc63b23a4bf89e90904d1e3ef83abdbaa966 Mon Sep 17 00:00:00 2001
From: Gergely Polonkai <gergely@polonkai.eu>
Date: Thu, 5 May 2022 16:31:59 +0200
Subject: [PATCH] Add an abstract base class for documents

---
 earthsnake/__init__.py          |  1 +
 earthsnake/document/__init__.py | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 earthsnake/document/__init__.py

diff --git a/earthsnake/__init__.py b/earthsnake/__init__.py
index 4aff3ca..4ebff3e 100644
--- a/earthsnake/__init__.py
+++ b/earthsnake/__init__.py
@@ -15,3 +15,4 @@ Usage example
 __version__ = '0.1.0'
 
 from .identity import Identity
+from .document import Document
diff --git a/earthsnake/document/__init__.py b/earthsnake/document/__init__.py
new file mode 100644
index 0000000..918967e
--- /dev/null
+++ b/earthsnake/document/__init__.py
@@ -0,0 +1,27 @@
+"""Document handling classes"""
+
+from abc import ABC, abstractmethod
+from datetime import datetime
+from typing import Optional
+
+from ..identity import Identity
+from ..path import Path
+
+
+class Document(ABC):  # pragma: no cover pylint: disable=too-few-public-methods
+    """Abstract base class for documents"""
+
+    path: Path
+
+    author: Identity
+
+    timestamp: datetime
+
+    signature: str
+
+    @abstractmethod
+    def sign(self, identity: Optional[Identity] = None) -> None:
+        """Sign the document as identity
+
+        If ``identity`` is ``None``, use ``self.author`` instead.
+        """