flash_helios_light.py: restore previous light color after flashing

The default light color (kind of white) is used to restore the previous
light color. This has a side-effect that changes to the lights by users
of the user interface will be lost. Instead we read the previous color
state and restore it once the flash is completed.

smuxi_hooks/on-message-received/flash_helios_light.py

@@ -3,7 +3,7 @@
 # A Smuxi hook script. This hooks flashes the ceiling light when a new message
 # on the #dimsumlabs channel was received.
 #
-# Copyright (C) 2021 Mirco Bauer <meebey@meebey.net>
+# Copyright (C) 2021, 2024 Mirco Bauer <meebey@meebey.net>
 # Copyright (C) 2021 Neil Pahl <neildaemond@gmail.com>
 # Copyright (C) 2021 Felix E. Klee <felix.klee@inka.de>
 
@@ -12,15 +12,34 @@
 import os
 import sys
 import time
+import re
 from os.path import exists
 
-DND_TIME_FILENAME="/home/pi/dsl-wall/smuxi_scripting_fun/dnd_expire_epoch.txt"
+DND_TIME_FILENAME="$HOME/dsl-wall/smuxi_scripting_fun/dnd_expire_epoch.txt"
 if exists(DND_TIME_FILENAME) == True:
-    dnd_file = open(DND_TIME_FILENAME, "r")
+    path = os.path.expandvars(DND_TIME_FILENAME);
+    dnd_file = open(path, "r")
     dnd_on = int(dnd_file.read().strip()) > time.time()
 else:
     dnd_on = False
 
+def get_ceiling_color(light_host):
+    request_url = light_host + 'rgb'
+    req = request.Request(request_url)
+    # timeout after 1 second as the light might be turned off
+    res = request.urlopen(req, data=None, timeout=1)
+    body = res.read().decode("ascii")
+    print("body: '{}'".format(body))
+    match = re.search("(?P<red>[0-9]+)\n" +
+                      "(?P<green>[0-9]+)\n" +
+                      "(?P<blue>[0-9]+).*",
+                      body)
+    if not match:
+        return None
+    return ( match.group('red'),
+             match.group('green'),
+             match.group('blue') )
+
 def change_ceiling_color(light_host, red, green, blue):
     color_url = 'rgb.lua?r={}&g={}&b={}'.format(red, green, blue)
     request_url = light_host + color_url
@@ -35,12 +54,20 @@ def change_ceiling_color(light_host, red, green, blue):
 if os.environ['SMUXI_MSG_TYPE'] != "Normal" or os.environ['SMUXI_CHAT_ID'] != "#dimsumlabs" or dnd_on:
     sys.exit(0)
 
-helios_service = 'http://helios/'
-#helios2_service = 'http://helios2/'
+helios_service = 'http://helios.in.dimsumlabs.com/'
+#helios2_service = 'http://helios2.in.dimsumlabs.com/'
 # HACK: disable helios2 as it is broken and needs repair. The HTTP/REST call
 # just hang forever...
 helios2_service = None
 
+# WTF: 0 is brightest value, lulz
+white = (0, 0, 0)
+
+current_color = get_ceiling_color(helios_service)
+if not current_color:
+    print('could not determine current color, assuming white...')
+    current_color = white
+
 # color value range 0 to 1024
 light_pink = (7, 751, 130)
 light_green = (783, 7, 652)
@@ -51,9 +78,7 @@ def change_ceiling_color(light_host, red, green, blue):
 # sleep for 1 second to give time for the color transition to complete
 sleep(1)
 
-# WTF: 0 is brightest value, lulz
-white = (0, 0, 0)
-change_ceiling_color(helios_service, *white)
+# restore to previous color
+change_ceiling_color(helios_service, *current_color)
 if helios2_service:
-    change_ceiling_color(helios2_service, *white)
-
+    change_ceiling_color(helios2_service, *current_color)