Tint the screen at night.

ansible/roles/waybar/files/waybar_scripts/waybar_night_mode.bash

@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+#
+# Power an icon for tinting the screen at night.
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+SLEEP_INTERVAL=${SLEEP_INTERVAL:-30}
+
+# ◓◒●◌◎
+# 🟠🟡🟢🟣🟤
+# 🟥🟦🟧🟨🟩🟪🟫
+# ☀☯⭐🌝🌞⏾
+# 🌑🌓🌗🌕
+# 👓
+
+############## Setup #########################
+
+function cleanup {
+    log "Killing child process $wlsunset_pid"
+    kill "$wlsunset_pid"
+    true
+}
+for sig in EXIT INT QUIT HUP TERM; do
+  trap "set +e; cleanup" "$sig"
+done
+
+function die {
+    local status_code="$1"
+    shift
+    (>&2 echo "${@}")
+    exit "$status_code"
+}
+
+function log {
+    (>&2 echo "${@}")
+}
+
+############## Program #########################
+
+function main {
+    local night_mode_icon night_mode_text night_mode_class
+    night_mode_mode="auto"
+    night_mode_class=""
+    wlsunset -l 40.7 -L -74.0 &
+    wlsunset_pid=$!
+
+    while true; do
+        if [ "$night_mode_mode" == "auto" ]; then
+            night_mode_icon="🌗"
+            night_mode_text="auto"
+        elif [ "$night_mode_mode" == "on" ]; then
+            night_mode_icon="🌑"
+            night_mode_text="night"
+        elif [ "$night_mode_mode" == "off" ]; then
+            night_mode_icon="🌕"
+            night_mode_text="day"
+        fi
+
+        render
+        sleep "$SLEEP_INTERVAL" &
+        wait $! || true
+    done
+}
+
+function render {
+    jq --unbuffered --compact-output <<EOF
+{
+"text":"${night_mode_icon}",
+"tooltip":"${night_mode_text}",
+"percentage":100,
+"class":"${night_mode_class}"
+}
+EOF
+}
+
+function handle_click {
+    if [ "$night_mode_mode" == "auto" ]; then
+        log "Setting night mode to force-day."
+        night_mode_mode="off"
+    elif [ "$night_mode_mode" == "on" ]; then
+        log "Setting night mode to auto."
+        night_mode_mode="auto"
+    elif [ "$night_mode_mode" == "off" ]; then
+        log "Setting night mode to force-night."
+        night_mode_mode="on"
+    fi
+    kill -USR1 "$wlsunset_pid"
+}
+
+trap "handle_click" SIGUSR1
+
+main "${@}"