From 7bd1a946edbb5d41ee036449975aeffcc261ddfa Mon Sep 17 00:00:00 2001
From: Paolo Lammens <lammenspaolo@gmail.com>
Date: Wed, 8 Jun 2022 11:29:27 +0200
Subject: [PATCH] fix: Clear O_NONBLOCK flag after using ainput()

This is to ensure we can still use regular blocking IO such as
input() and print() after using ainput.

Fixes #17, #19
---
 src/loveletter_cli/session.py  |  2 +-
 src/loveletter_cli/ui/input.py | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/loveletter_cli/session.py b/src/loveletter_cli/session.py
index 3915ecc..1a603fe 100644
--- a/src/loveletter_cli/session.py
+++ b/src/loveletter_cli/session.py
@@ -9,7 +9,6 @@
 
 import more_itertools as mitt
 import valid8
-from aioconsole import ainput
 from multimethod import multimethod
 
 import loveletter.game
@@ -22,6 +21,7 @@
 from loveletter_cli.exceptions import Restart
 from loveletter_cli.server_process import ServerProcess
 from loveletter_cli.ui import (
+    ainput,
     async_ask_valid_input,
     draw_game,
     pause,
diff --git a/src/loveletter_cli/ui/input.py b/src/loveletter_cli/ui/input.py
index b1cdcf3..1d588d2 100644
--- a/src/loveletter_cli/ui/input.py
+++ b/src/loveletter_cli/ui/input.py
@@ -1,11 +1,12 @@
 import enum
 import functools
+import sys
 import textwrap
 from typing import Callable, Tuple, Type, TypeVar
 
+import aioconsole
 import more_itertools
 import valid8
-from aioconsole import ainput
 
 from .misc import printable_width
 
@@ -14,6 +15,22 @@
 _DEFAULT = object()
 
 
+# Define ainput() based on OS: if the OS uses the O_NONBLOCK flag, we have to
+# clear it after every call to ainput() to ensure compatibility with blocking
+# IO such as print() and input().
+try:
+    import fcntl  # noqa
+except ImportError:
+    ainput = aioconsole.ainput
+else:
+
+    @functools.wraps(aioconsole.ainput)
+    async def ainput(*args, **kwargs):
+        result = await aioconsole.ainput(*args, **kwargs)
+        fcntl.fcntl(sys.stdin.fileno(), fcntl.F_SETFL, 0)
+        return result
+
+
 def ask_valid_input(*args, **kwargs) -> _T:
     error_message, parser, prompt, validation_errors = _ask_valid_input_parse_args(
         *args, **kwargs
@@ -162,4 +179,6 @@ async def pause() -> None:
     # the user has to enter twice before input is detected;
     # but the asynchronous nature is needed to ensure other events are handled in time
     # (e.g. when the connection is lost).
+    # Also caused trouble on Linux and Unix regarding the O_NONBLOCK flag
+    # (see #17 and #19) but this has been fixed.
     await ainput("Enter something to continue... ")