From b6f28b2ec6b9e9be76b23e57686a9539e9ff7c03 Mon Sep 17 00:00:00 2001
From: Dan <14043624+delivrance@users.noreply.github.com>
Date: Mon, 9 Apr 2018 23:30:50 +0200
Subject: [PATCH] Add base Filter class

---
 pyrogram/client/filters/filter.py | 57 +++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 pyrogram/client/filters/filter.py

diff --git a/pyrogram/client/filters/filter.py b/pyrogram/client/filters/filter.py
new file mode 100644
index 00000000..feec51df
--- /dev/null
+++ b/pyrogram/client/filters/filter.py
@@ -0,0 +1,57 @@
+# Pyrogram - Telegram MTProto API Client Library for Python
+# Copyright (C) 2017-2018 Dan Tès <https://github.com/delivrance>
+#
+# This file is part of Pyrogram.
+#
+# Pyrogram is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pyrogram is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.
+
+
+class Filter:
+    def __call__(self, message):
+        raise NotImplementedError
+
+    def __invert__(self):
+        return InvertFilter(self)
+
+    def __and__(self, other):
+        return AndFilter(self, other)
+
+    def __or__(self, other):
+        return OrFilter(self, other)
+
+
+class InvertFilter(Filter):
+    def __init__(self, base):
+        self.base = base
+
+    def __call__(self, message):
+        return not self.base(message)
+
+
+class AndFilter(Filter):
+    def __init__(self, base, other):
+        self.base = base
+        self.other = other
+
+    def __call__(self, message):
+        return self.base(message) and self.other(message)
+
+
+class OrFilter(Filter):
+    def __init__(self, base, other):
+        self.base = base
+        self.other = other
+
+    def __call__(self, message):
+        return self.base(message) or self.other(message)