#!/bin/bash
if [[ "$1" != "m" && "$1" != "u" ]] || [ ${#2} -lt 1 ] || [[ "$1" != "u" && ${#3} -lt 1 ]]; then
	echo "tcmount - mount or unmount a TrueCrypt volume"
	echo "usage: $0 [m|u] mapmountname [path/to/file/or/device]"
	echo "    m - mounts a volume container file/device"
	echo "    u - unmounts a volume"
	echo "mapmountname will be used to mkdirs in /media/`whoami` and /dev/mapper"
	echo
	exit 1
fi

mountit () {
	local uid=`id -u`
	local user=`whoami`
	local device=`sudo losetup -f`
	local passwd=
	local tcvol="$2"
	local mapping=$1
	if [ ! -e "$tcvol" ]; then echo "error: volume "$tcvol" does not exist"; exit 1; fi
	if [ -d "$tcvol" ]; then echo "error: volume "$tcvol" is directory"; exit 1; fi
	if [ ! -d "/home/$user/.tcmount" ]; then mkdir "/home/$user/.tcmount"; fi
	if [ -e "/home/$user/$mapping" ]; then echo "error: mapping already exists for $mapping"; exit 1; fi
	echo "preparing to mount $tcvol to /media/$user/$mapping"
	echo $device > /home/$user/.tcmount/$mapping
	sudo mkdir /media/$user/$mapping
	sudo losetup $device "$tcvol"
	sudo tcplay --map=$mapping --device=$device
	sudo mount -o uid=$uid /dev/mapper/$mapping /media/$user/$mapping
	exit 0
}

unmountit () {
	local uid=`id -u`
        local user=`whoami`
	local mapping=$1
	if [ ! -d "/home/$user/.tcmount" ]; then echo "error: ~/.tcmount directory missing"; exit 1; fi
	if [ ! -f "/home/$user/.tcmount/$mapping" ]; then echo "error: ~/.tcmount/$mapping file (contains loop name) is missing"; exit 1; fi
	local device=`cat /home/$user/.tcmount/$mapping`
	if [ ! -d "/media/$user/$mapping" ]; then echo "error: /media/$user/$mapping is not a directory or does not exist"; exit 1; fi
	echo "preparing to unmount /media/$user/$mapping"
	sudo umount /media/$user/$mapping
	sudo tcplay -u /dev/mapper/$mapping
	rm /home/$user/.tcmount/$mapping
	sudo rmdir /media/$user/$mapping
	exit 0
}

if [ "$1" == "m" ]; then
	mountit $2 "$3"
elif [ "$1" == "u" ]; then
	unmountit $2
fi