#!/bin/sh 

### TrueCrypt Mount wrapper
### This file is a part of `truecrypt-extra`
###
### (c) Andrew Sichevoi, http://thekondor.net
### Distributed in the terms of GNU GPL v3.0+ license
###
### The latest version is available on http://git.thekondor.net

if [ -f /etc/default/truecrypt ]; then
  . /etc/default/truecrypt
fi

run_textual_truecrypt()
{
  ${TRUECRYPT_BINARY} --text --non-interactive $@ 2>/dev/null
}

run_regular_truecrypt()
{
  ${TRUECRYPT_BINARY} $@
}

setup_defaults_if_not_available()
{
  DEFAULT_USER_MOUNT_ROOT=/home/%username%/.mount/encrypted

  if [ -z "${USER_MOUNT_ROOT}" ]; then
    USER_MOUNT_ROOT=${DEFAULT_USER_MOUNT_ROOT}
  fi

  DEFAULT_TRUECRYPT_BINARY=/usr/bin/truecrypt
  if [ -z "${TRUECRYPT_BINARY}" ]; then
    TRUECRYPT_BINARY=${DEFAULT_TRUECRYPT_BINARY}
  fi

  DEFAULT_EXPLORE_MOUNTED_VOLUME=true
  if [ -z "${EXPLORE_MOUNTED_VOLUME}" ]; then
    EXPLORE_MOUNTED_VOLUME=${DEFAULT_EXPLORE_MOUNTED_VOLUME}
  fi

  DEFAULT_ERROR_REPORTING_CHANNEL='/bin/echo %error%'
  if [ -z "${ERROR_REPORTING_CHANNEL}" ]; then
    ERROR_REPORTING_CHANNEL=${DEFAULT_ERROR_REPORTING_CHANNEL}
  fi
}

check_if_mount_point_already_used()
{
  _MOUNT_POINT_DIR=$1
  _IS_LISTED_IN_TRUECRYPT=$(run_textual_truecrypt --list | grep "${_MOUNT_POINT_DIR}" -c)
  if [ 0 -eq $? -a ! 0 -eq ${_IS_LISTED_IN_TRUECRYPT} ]; then
    raise_error "Error: mount point '${_MOUNT_POINT_DIR}' is already used by truecrypt. It cannot be used right now."
  fi
}

check_if_truecrypt_available()
{
  if [ ! -x "${TRUECRYPT_BINARY}" ]; then
    raise_error "Error: Truecrypt (${TRUECRYPT_BINARY}) is not available"
  fi
}

raise_error()
{
  _ERROR_MESSAGE=$(/bin/echo -n "$@" | sed -e 's/\\/\\\\/g' | sed -e "s/\//::/g" | tr \" \')
  _ERROR_CMD=$(/bin/echo ${ERROR_REPORTING_CHANNEL} | sed -e "s/%error%/${_ERROR_MESSAGE}/g")
  eval "${_ERROR_CMD}"
  exit 1
}

check_passed_arguments()
{
  if [ 1 != $# ]; then
    raise_error "Usage: ${0} <truecrypt-volume>"
  fi
}

escape_mount_dir_name()
{
  /bin/echo $@ | /usr/bin/tr "[:cntrl:][:space:][:punct:]" "_"
}

generate_mount_point_dir_name()
{
  escape_mount_dir_name $1
}

generate_mount_point()
{
  _MOUNT_POINT_DIR=$(/bin/echo ${USER_MOUNT_ROOT}/$(generate_mount_point_dir_name $1))
  _USERNAME_VAR=$(whoami)
  _MOUNT_POINT_DIR=$(/bin/echo ${_MOUNT_POINT_DIR} | /bin/sed -e s/%username%/${_USERNAME_VAR}/g)
  
  /bin/echo ${_MOUNT_POINT_DIR}
}

create_mount_point()
{
  _MOUNT_POINT_DIR=$1
  if [ ! -d "${_MOUNT_POINT_DIR}" ]; then
    /bin/mkdir -p ${_MOUNT_POINT_DIR}
    if [ ! 0 -eq $? ]; then
      raise_error "Error: failed to create ${_MOUNT_POINT_DIR}"
    fi
  fi
}

explore_mount_point()
{
  if [ ${EXPLORE_MOUNTED_VOLUME} ]; then
    _MOUNT_POINT_DIR=${1}
    /usr/bin/xdg-open ${_MOUNT_POINT_DIR}
  fi
}

mount_tc_volume()
{
  _TC_VOLUME=${1}
  _MOUNT_POINT_DIR=$(generate_mount_point ${_TC_VOLUME})

  check_if_mount_point_already_used ${_MOUNT_POINT_DIR}
  create_mount_point ${_MOUNT_POINT_DIR}

  run_regular_truecrypt ${_TC_VOLUME} ${_MOUNT_POINT_DIR}
  if [ ! 0 -eq $? ]; then
    raise_error "Error: truecrypt execution error, code = ${?}"
  fi

  explore_mount_point ${_MOUNT_POINT_DIR}
}


check_passed_arguments $@
setup_defaults_if_not_available
mount_tc_volume $1