From f70de55ec9b55b90effa093495c32d874f11a35f Mon Sep 17 00:00:00 2001
From: Alexander Bocken <alexander@bocken.org>
Date: Sun, 28 Jun 2020 14:04:09 +0200
Subject: [PATCH] removes unnecessary power option depending on power state

---
 bt | 96 +++++++++++++++++++++++++++++++++++++-------------------------
 1 file changed, 57 insertions(+), 39 deletions(-)

diff --git a/bt b/bt
index 6e2cadd..b3ba1cd 100755
--- a/bt
+++ b/bt
@@ -4,17 +4,14 @@ SCAN_PERIOD=5
 #locations of blacklist and hard coded list of paired devices (watch out, need to modify Makefile as well if you want to change these values and still use make install)
 BLACKLIST=${XDG_DATA_HOME:-$HOME/.local/share}/bt/blacklist
 PAIRLIST=${XDG_DATA_HOME:-$HOME/.local/share}/bt/paired
-AUTOTRUST=true
-actions="turn off
-turn on
-pair
+
+actions="pair
+disconnect
 unpair"
 
-if ! $AUTOTRUST; then
-	actions+="
-trust"
-fi
-
+#get power state of bluetooth controller
+powerstatus="$( bluetoothctl show | grep Powered | awk '{print $2}' )"
+scanstatus="$( bluetoothctl show | grep Discovering | awk '{print $2}' )"
 
 #Checks for necessary programs to be present. Very unlikely not to be present but let's just err on the safer side.
 for prog in dmenu bluetoothctl awk cat date nl; do
@@ -24,9 +21,20 @@ for prog in dmenu bluetoothctl awk cat date nl; do
    fi
 done
 
-#start scanning as early as possible to speed up pairing process:
-bluetoothctl power on & bluetoothctl scan on &>/dev/null &
-start_scan="$( date +'%s' )"
+poweron(){
+	[ "$powerstatus" = "no" ] && bluetoothctl power on
+}
+scanon(){
+	if [ "$scanstatus" = "no" ]; then
+	bluetoothctl scan on &
+	start_scan="$( date +'%s' )"
+fi
+}
+
+#start scanning as early as possible to speed up pairing process
+#=> maybe use an option to do this? Otherwise ever invocation of bt powers on the controller.
+poweron
+scanon
 
 #Compile list of all Bluetooth IDS of paired devices (from bluetoothctl and from hardcoded list)
 bt_IDS="$( ( bluetoothctl paired-devices && cat "$PAIRLIST" ) | sort -u | awk '{print $2}' )"
@@ -35,10 +43,14 @@ bt_IDS="$( ( bluetoothctl paired-devices && cat "$PAIRLIST" ) | sort -u | awk '{
 paired_devices="$( ( bluetoothctl paired-devices && cat "$PAIRLIST" ) | sort -u | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' )"
 
 disp_devices="$( echo "$paired_devices" | grep -vf "$BLACKLIST"  )"
+echo "$paired_devices"
+echo ----------------
+echo "$disp_devices"
 
+poweroption="$( echo "$powerstatus" | sed 's/yes/power off/; s/no/power on/' )"
 #Don't print empty device list, removes unnecessary empty choice in dmenu
-[ "$disp_devices" = "" ] && choice=$( echo "$actions" | dmenu -i -p 'What BT action would you like to perform:' )
-[ "$disp_devices" != "" ] && choice=$( ( echo "$disp_devices" && echo "$actions" ) | dmenu -i -p 'What BT action would you like to perform:' )
+[ "$disp_devices" = "" ] && choice=$( printf "%s\n%s" "$poweroption" "$actions" | dmenu -i -p 'What BT action would you like to perform:' )
+[ "$disp_devices" != "" ] && choice=$( ( echo "$disp_devices" && printf "%s\n%s" "$poweroption" "$actions"  ) | dmenu -i -p 'What BT action would you like to perform:' )
 
 cleanup(){
 	bluetoothctl scan off
@@ -47,8 +59,8 @@ cleanup(){
 
 pair(){
 	#since this function can get called indefinitely, make sure to always be scanning and controller has power in the case that it got deactived by some other process.
-	bluetoothctl power on &>/dev/null &
-	bluetoothctl scan on &>/dev/null &
+	#bluetoothctl power on &>/dev/null &
+	#bluetoothctl scan on &>/dev/null &
 #check whether $SCAN_PERIOD seconds has already passed since starting scanning, if not, wait for the rest of that time.
 	if [ $((( "$(date +'%s')" - "$start_scan" ))) -lt $SCAN_PERIOD ]; then
 		sleep_period="$((( "$SCAN_PERIOD" - "$( date +'%s')" + "$start_scan" )))"
@@ -60,10 +72,15 @@ pair(){
 
 		sleep "$sleep_period"
 	fi
-	echo "$paired_devices" > /tmp/paired_devices
-	new_devices="$( bluetoothctl devices | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' | grep -vf /tmp/paired_devices )"
-	rm -f /tmp/paired_devices
-	choice=$( (echo "$new_devices" && echo 'rescan' ) | dmenu -l 10 -i -p 'pair with which device?' )
+	if [ $paired_devices = "" ]; then
+		echo "$paired_devices" > /tmp/paired_devices
+		new_devices="$( bluetoothctl devices | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' | grep -vf /tmp/paired_devices )"
+		rm -f /tmp/paired_devices
+	else
+		new_devices="$( bluetoothctl devices | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' )"
+	fi
+	[ $new_devices = "" ] && options="rescan" || options=$(echo "$new_devices" && echo 'rescan')
+	choice=$( echo "$options" | dmenu -l 10 -i -p 'pair with which device?' )
 	if [ -n "$choice" ]; then
 		if [ "$choice" = "rescan" ]; then
 			start_scan="$( date +'%s')"
@@ -79,22 +96,20 @@ pair(){
 			bluetoothctl trust "$dev_id"
 		fi
 		#if device is not already hard coded as paired, add to paired devices list
-		if grep -q "$dev_id" "$PAIRLIST"
+		if [ "$( grep "$dev_id" "$PAIRLIST")" != "" ]
 		then
+			echo to be added to $PAIRLIST
+			echo Device "$dev_id" "$choice"
 			echo Device "$dev_id" "$choice" >> "$PAIRLIST"
 		fi
 	fi
-	cleanup
 }
 
 case $choice in
-	"turn on") bluetoothctl power on
-		cleanup;;
-	"turn off") bluetoothctl power off
-		cleanup;;
+	"turn on") bluetoothctl power on;;
+	"turn off") bluetoothctl power off;;
 	"scan on") bluetoothctl power on && echo power on && sleep 2
-		([ -n "$TERMINAL" ] && $TERMINAL -e bluetoothctl scan on ) || st bluetoothctl scan on
-		cleanup;;
+		([ -n "$TERMINAL" ] && $TERMINAL -e bluetoothctl scan on ) || st bluetoothctl scan on;;
 	"pair") pair;;
 	"unpair") choice=$( echo "$paired_devices" | dmenu -l 10 -i -p 'remove which paired device?')
 		if [ -n "$choice" ]; then
@@ -104,22 +119,25 @@ case $choice in
 			#remove device to unpair from hard coded paired devices list
 			new_paired_list="$( grep -v "$dev_id" "$PAIRLIST" )"
 			echo "$new_paired_list" > "$PAIRLIST"
-		fi
-		cleanup;;
+		fi;;
 	"trust") choice=$( echo "$paired_devices" | dmenu -l 10 -i -p 'remove which paired device?')
 		if [ -n "$choice" ]; then
 			dev_no=$( echo "$paired_devices" | nl | grep -P "[0-9]+\t$choice$" | awk '{print $1}')
 			dev_id=$( echo "$bt_IDS" | nl | grep -P "^.*$dev_no\t" | awk '{print $2}' )
 			bluetoothctl trust "$dev_id"
-		fi
+		fi;;
+	"disconnect") choice=$( echo "$paired_devices" | dmenu -l 10 -i -p 'remove which paired device?')
+			if [ -n "$choice" ]; then
+				dev_no=$( echo "$paired_devices" | nl | grep -P "[0-9]+\t$choice$" | awk '{print $1}')
+				dev_id=$( echo "$bt_IDS" | nl | grep -P "^.*$dev_no\t" | awk '{print $2}' )
+				bluetoothctl disconnect "$dev_id"
+			fi;;
+	"*")
+		dev_no=$( echo "$paired_devices" | nl | grep -P "[0-9]+\t$choice$" | awk '{print $1}')
+		dev_id=$( echo "$bt_IDS" | nl | grep -P "^.*$dev_no\t" | awk '{print $2}')
+		bluetoothctl power on
+		bluetoothctl pair "$dev_id"
+		bluetoothctl connect "$dev_id";;
 esac
 
-if [ -n "$choice" ]; then
-	dev_no=$( echo "$paired_devices" | nl | grep -P "[0-9]+\t$choice$" | awk '{print $1}')
-	dev_id=$( echo "$bt_IDS" | nl | grep -P "^.*$dev_no\t" | awk '{print $2}')
-	bluetoothctl power on
-	bluetoothctl pair "$dev_id"
-	bluetoothctl connect "$dev_id"
-fi
-
 cleanup