bthandler/bt

#!/bin/bash
#wait time to discover new devices in seconds
SCAN_PERIOD=5
BLACKLIST=${XDG_DATA_HOME:-$HOME/.local/share}/bt/blacklist
PAIRLIST=${XDG_DATA_HOME:-$HOME/.local/share}/bt/paired
actions="turn off\nturn on\npair\nunpair"

#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; do
   if ! hash "$prog" 2>/dev/null; then
      printf 'bthandler: %s: command not found\n' "$prog" >&2
      exit 127
   fi
done

#Compile list of all Bluetooth IDS of paired devices (from bluetoothctl and from hardcoded list)
bluetoothctl paired-devices | awk '{print $2}' > /tmp/bt_IDS
cat "$PAIRLIST" | awk '{print $2}' >> /tmp/bt_IDS
echo bt_IDS:
cat /tmp/bt_IDS
bt_IDS="$( cat /tmp/bt_IDS | sort -u )"
[ -n "$bt_IDS" ] && echo "$bt_IDS" > /tmp/bt_IDS
echo bt_IDS sorted:
cat /tmp/bt_IDS

#Compile list of all device Names of paired devices (from bluetoothctl and from hardcoded list)
bluetoothctl paired-devices | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' > /tmp/paired_devices
echo paired_devices:
cat /tmp/paired_devices
cat "$PAIRLIST" | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' >> /tmp/paired_devices
paired_devices="$( cat /tmp/paired_devices | sort -u )"
[ -n "$paired_devices" ] && echo "$paired_devices" > /tmp/paired_devices
echo paired_devices sorted:
cat /tmp/paired_devices


grep -vf "$BLACKLIST" /tmp/paired_devices > /tmp/disp_devices

#Don't print empty device list, removes unnecessary empty choice in dmenu
len=$(cat /tmp/disp_devices | wc -l)
echo len: $len
[ $len -eq 0 ] && choice=$( printf "$actions" | dmenu -i -p 'What BT action would you like to perform:' )
[ $len -gt 0 ] && choice=$( printf "$(< /tmp/disp_devices)\n$actions" | dmenu -i -p 'What BT action would you like to perform:' )

cleanup(){
	rm -f /tmp/bt_devices
	rm -f /tmp/bt_IDS
	rm -f /tmp/paired_devices
	rm -f /tmp/new_devices
	rm -f /tmp/disp_devices
	bluetoothctl scan off > /dev/null
	exit 0
}

case $choice in
	"turn on") bluetoothctl power on
		cleanup;;
	"turn off") bluetoothctl power off
		cleanup;;
	"scan on") bluetoothctl power on && echo power on && sleep 2
		[ -n $TERMINAL ] && ($TERMINAL -e bluetoothctl scan on ) || st bluetoothctl scan on
		cleanup;;
	"pair") bluetoothctl power on
		bluetoothctl scan on & disown
		notify-send "Bluetooth" "Searching for devices, please wait a bit"
		sleep $SCAN_PERIOD
		bluetoothctl devices | awk '{for (i=3; i<NF; i++) printf $i " "; print $NF}' > /tmp/bt_devices
		grep -vf /tmp/paired_devices /tmp/bt_devices > /tmp/new_devices
		choice=$( cat /tmp/new_devices | dmenu -l 10 -i -p 'pair with which device?' )
		if [ -n "$choice" ]; then
			bluetoothctl devices | awk '{print $2}' > /tmp/bt_IDS
			dev_no=$(cat -n /tmp/bt_devices | grep "$choice" | awk '{print $1}')
			dev_id=$(cat -n /tmp/bt_IDS | grep -E $dev_no"[[:space:]]" | awk '{print $2}' )

			bluetoothctl pair $dev_id && sleep 2
			bluetoothctl connect $dev_id
			#if device is not already hard coded as paired, add to paired devices list
			echo grep: $( grep $dev_id "$PAIRLIST" )
			if [ -z $( grep $dev_id "$PAIRLIST" ) ]; then
				echo "Device $dev_id $choice" >> "$PAIRLIST"
			fi
		fi
		cleanup;;
	"unpair") choice=$( cat /tmp/paired_devices | dmenu -l 10 -i -p 'remove which paired device?')
		if [ -n "choice" ]; then
			dev_no=$(cat -n /tmp/paired_devices | grep "$choice" | awk '{print $1}')
			dev_id=$(cat -n /tmp/bt_IDS | grep -E $dev_no"[[:space:]]" | awk '{print $2}' )
			bluetoothctl remove $dev_id
			#remove device to unpair from hard coded paired devices list
			new_paired_list="$( grep -v "$dev_id" "$PAIRLIST" )"
			echo "$new_paired_list" > "$PAIRLIST"
		fi
		cleanup;;
esac

if [ -n "$choice" ]; then
	dev_no=$(cat -n /tmp/paired_devices | grep "$choice" | awk '{print $1}')
	dev_id=$(cat -n /tmp/bt_IDS | grep $dev_no | awk '{print $2}')
	bluetoothctl power on
	bluetoothctl connect $dev_id
fi

cleanup