sane-input-handler: implement --verbose flag

hosts/common/programs/sane-input-handler/sane-input-handler

@@ -60,10 +60,8 @@ VOL_INCR=5
 KEYBOARD="${KEYBOARD:-wvkbd-mobintl}"
 CAMERA="${CAMERA:-org.postmarketos.Megapixels.desktop}"
 
-action="$1"
-
 showHelp() {
-  echo "usage: sane-input-handler <action>"
+  echo "usage: sane-input-handler [--verbose] <action>"
   echo ""
   echo "where action is one of:"
   echo "- power_tap_{1,2}"
@@ -81,7 +79,18 @@ showHelp() {
 }
 
 log() {
-  printf "sane-input-handler: %s\n" "$1"
+  printf "sane-input-handler: %s\n" "$1" >&2
+}
+
+debug() {
+  if [ -n "$VERBOSE" ]; then
+    log "$@"
+  fi
+}
+
+trace() {
+  debug "$*"
+  "$@"
 }
 
 ## HELPERS
@@ -89,7 +98,7 @@ log() {
 # swaySetOutput true|false
 # turns the display on or off
 swaySetOutput() {
-  swaymsg -- output '*' power "$1"
+  trace swaymsg -- output '*' power "$1"
 }
 # swaySetTouch enabled|disabled
 # turns touch input on or off
@@ -99,7 +108,7 @@ swaySetTouch() {
 
   local inputs=$(swaymsg -t get_inputs --raw | jq '. | map(select(.type == "touch")) | map(.identifier) | join(" ")' --raw-output)
   for id in "${inputs[@]}"; do
-    swaymsg -- input "$id" events "$1"
+    trace swaymsg -- input "$id" events "$1"
   done
 }
 
@@ -171,7 +180,7 @@ toggleKeyboard() {
     # `env` so that we get the right `kill` binary instead of bash's builtin
     # `kill` only one keyboard process. in the case of e.g. sandboxing,
     # the keyboard might consist of multiple processes and each one we signal would cause a toggle
-    if env kill -s RTMIN+0 "$p"; then
+    if trace env kill -s RTMIN+0 "$p"; then
       break
     fi
   done
@@ -292,27 +301,43 @@ dispatchToplevel() {
   _isAllOn="$(isAllOn && echo 1 || true)"
 
   if [ -z "$_isAllOn" ]; then
-    dispatchOff
+    trace dispatchOff
   else
     _isInhibited="$(isInhibited && echo 1 || true)"
     if [ -n "$_isInhibited" ]; then
-      dispatchInhibited
+      trace dispatchInhibited
     else
-      dispatchOn
+      trace dispatchOn
     fi
   fi
 
-  dispatchDefault
+  trace dispatchDefault
 }
 
-case "$action" in
-  (--help)
-    showHelp
-    exit 0
-    ;;
-  (*)
-    dispatchToplevel
-    handleWith unmapped
-    ;;
-esac
+action=
+doShowHelp=
+parseArgs() {
+  for arg in "$@"; do
+    case "$arg" in
+      (-h|--help)
+        doShowHelp=1
+        ;;
+      (-v|--verbose)
+        VERBOSE=1
+        ;;
+      (*)
+        action="$arg"
+        ;;
+    esac
+  done
+}
 
+parseArgs "$@"
+
+if [ -n "$doShowHelp" ]; then
+  showHelp
+  exit 0
+fi
+
+trace dispatchToplevel
+handleWith unmapped