#!/bin/bash
#wait time to discover new devices in seconds
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
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)
bt_IDS="$( ( bluetoothctl paired-devices && cat "$PAIRLIST" ) | sort -u | awk '{print $2}' )"

#Compile list of all device Names of paired devices (from bluetoothctl and from hardcoded list)
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 "$BLACKLIST"  )"
#echo disp_devices:"$disp_devices"test

#Don't print empty device list, removes unnecessary empty choice in dmenu
[ "$disp_devices" = "" ] && choice=$( printf $actions | dmenu -i -p 'What BT action would you like to perform:' )
[ "$disp_devices" != "" ] && choice=$( printf "%s\n$actions" "$disp_devices" | dmenu -i -p 'What BT action would you like to perform:' )

cleanup(){
	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 $SCAN_PERIOD
		echo "$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 "$new_devices" | dmenu -l 10 -i -p 'pair with which device?' )
		if [ -n "$choice" ]; then
			bt_IDS="$( bluetoothctl devices | awk '{print $2}' )"
			dev_no=$( echo "$new_devices" | nl | grep "$choice" | awk '{print $1}')
			dev_id=$( echo "$bt_IDS" | nl | grep -P "^.*$dev_no\t" | 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" "$PAIRLIST" )"
			if grep -q "$dev_id" "$PAIRLIST"
			then
				echo Device "$dev_id" "$choice" >> "$PAIRLIST"
			fi
		fi
		cleanup;;
	"unpair") choice=$( echo "$paired_devices" | dmenu -l 10 -i -p 'remove which paired device?')
		if [ -n "$choice" ]; then
			dev_no=$(cat -n /tmp/paired_devices | grep -E "^[0-9]*\tDevice [0-9:].* $choice$" | awk '{print $1}')
			dev_id=$( echo "$bt_IDS" | nl | grep -E "$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 "$choice" ]; then
	#echo paired_devices: "$( echo "$paired_devices" | nl )"
	dev_no=$( 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 $2}')
	#echo dev_no:"$dev_no"
	#echo dev_id:"$dev_id"
	#echo choice:"$choice"
	bluetoothctl power on
	bluetoothctl pair "$dev_id"
	bluetoothctl connect "$dev_id"
fi

cleanup