#!/bin/bash

#this script attempts to pair a Mobilinkd TNC with the Pi.
#04MARCH2022 KM4ACK

EXISTING=`bluetoothctl paired-devices | grep Mobilinkd`
TMP=/run/user/$UID/mobi.txt

#see if we already have a TNC paired
if [ -n "$EXISTING" ]; then
clear;echo;echo
cat <<EOF
A Mobilinkd TNC is already paired with this pi.
Remove the existing pairing and try again.
EOF
sleep 3
exit 1
fi

if ! hash expect 2>/dev/null; then
echo "We are missing a dependency....expect"
echo "Hang on while it is installed"
echo "You can press ctrl+c to exit"
sleep 3
sudo -A apt update
sudo -A apt install -y expect
fi

#create connect script in RAM memory. (Called later from this script)
cat << "MYFILE" > /run/user/$UID/connect
#!/usr/bin/expect -f

set prompt "#"
set address [lindex $argv 0]

spawn sudo -A bluetoothctl
expect -re $prompt
send "scan on\r"
send_user "\nStandby\r"
sleep 10
send_user "\nStill working\r"
send "scan off\r"
expect "Controller"
send "pair $address\r"
sleep 5
send "1234\r"
sleep 3
send_user "\nShould be paired now.\r"
send "quit\r"
expect eof
MYFILE
chmod +x /run/user/$UID/connect

#give user some feedback
echo;echo; clear
cat <<EOF
####################################################################
#   Please stand by while the pairing is attempted.                #
#   This process takes approximately 60 seconds to complete.       #
####################################################################
EOF

#get the TNC of the mobilinkd
echo "Discovering nearby Mobilinkd device....please wait"
hcitool scan > $TMP
echo "Discovery complete. TNC found.";echo
MAC=`grep -i TNC /run/user/$UID/mobi.txt | awk '{print $1}'`
#verify we have a MAC address to work with
	if [ -z "$MAC" ]; then
	echo "TNC not found. Can't continue!"
	echo "Confirm that the TNC is on and has"
	echo "a fast flashing blue light."
	sleep 5
	exit 1
	fi
echo "Starting the pairing process....please stand by"
#call the connect script
/run/user/$UID/connect $MAC >/dev/null 2>&1
echo;echo "The pairing was probably successful" 
echo "Start the Mobilinkd modem again"
sleep 3