From 8817f991a59d0071530b094cb8ba01af64ebd3f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Fri, 1 Jun 2018 14:00:44 +0200
Subject: [PATCH] Use power of LazyInitialise to murder TFW/TAOENV global state

---
 lib/envvars/__init__.py   | 21 ++++++++++++++++-----
 lib/tao/config/envvars.py |  4 ++--
 lib/tfw/config/envvars.py |  4 ++--
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/lib/envvars/__init__.py b/lib/envvars/__init__.py
index 712a926..11faa64 100644
--- a/lib/envvars/__init__.py
+++ b/lib/envvars/__init__.py
@@ -4,9 +4,20 @@
 from collections import namedtuple
 from os import environ
 
+from tfw.decorators import LazyInitialise
 
-def prefixed_envvars_to_namedtuple(prefix: str, tuple_name: str):
-    envvars = {envvar.replace(prefix, '', 1): environ.get(envvar)
-               for envvar in environ.keys()
-               if envvar.startswith(prefix)}
-    return namedtuple(tuple_name, envvars)(**envvars)
+
+class LazyEnvironment:
+    def __init__(self, prefix, tuple_name):
+        self._prefix = prefix
+        self._tuple_name = tuple_name
+
+    @LazyInitialise
+    def environment(self):
+        return self.prefixed_envvars_to_namedtuple()
+
+    def prefixed_envvars_to_namedtuple(self):
+        envvars = {envvar.replace(self._prefix, '', 1): environ.get(envvar)
+                   for envvar in environ.keys()
+                   if envvar.startswith(self._prefix)}
+        return namedtuple(self._tuple_name, envvars)(**envvars)
diff --git a/lib/tao/config/envvars.py b/lib/tao/config/envvars.py
index da46222..260d057 100644
--- a/lib/tao/config/envvars.py
+++ b/lib/tao/config/envvars.py
@@ -1,6 +1,6 @@
 # Copyright (C) 2018 Avatao.com Innovative Learning Kft.
 # All Rights Reserved. See LICENSE file for details.
 
-from envvars import prefixed_envvars_to_namedtuple
+from envvars import LazyEnvironment
 
-TAOENV = prefixed_envvars_to_namedtuple('AVATAO_', 'taoenvtuple')
+TAOENV = LazyEnvironment('AVATAO_', 'taoenvtuple').environment
diff --git a/lib/tfw/config/envvars.py b/lib/tfw/config/envvars.py
index f239d5c..ef590c6 100644
--- a/lib/tfw/config/envvars.py
+++ b/lib/tfw/config/envvars.py
@@ -1,6 +1,6 @@
 # Copyright (C) 2018 Avatao.com Innovative Learning Kft.
 # All Rights Reserved. See LICENSE file for details.
 
-from envvars import prefixed_envvars_to_namedtuple
+from envvars import LazyEnvironment
 
-TFWENV = prefixed_envvars_to_namedtuple('TFW_', 'tfwenvtuple')
+TFWENV = LazyEnvironment('TFW_', 'tfwenvtuple').environment