#!/bin/bash
###########################################################################
#
# Copyright (c) 2022-2023 Diality Inc. - All Rights Reserved.
#
# THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
# WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
#
# @file    crypt_setup.sh
#
# @author  (last)      Behrouz NematiPour
# @date    (last)      15-May-2023
# @author  (original)  Behrouz NematiPour
# @date    (original)  15-May-2023
#
############################################################################


ERR_CRYPTSETUP_UNKNOWN=100

ERR_CRYPTSETUP_USAGE=101
ERR_CRYPTSETUP_PASSWORD=102

ERR_CRYPTSETUP_UMOUNT=111
ERR_CRYPTSETUP_CLOSE=112

ERR_CRYPTSETUP_CREATE_MKDIR=121
ERR_CRYPTSETUP_CREATE_FORMAT=122
ERR_CRYPTSETUP_CREATE_OPEN=123
ERR_CRYPTSETUP_CREATE_MKFS=124
ERR_CRYPTSETUP_CREATE_MOUNT=125

ERR_CRYPTSETUP_MOUNT_OPEN=131
ERR_CRYPTSETUP_MOUNT_MOUNT=132

LOC_DEV="/dev/mmcblk0p7"
LOC_DIR="configurations"
LOC_MAP="/dev/mapper/"$LOC_DIR
LOC_VAR="/var/"$LOC_DIR

function checkPassword() {
    if [ "$PASSWORD" == "" ]; then
        echo "setup command missing password argument"
        exit $ERR_CRYPTSETUP_PASSWORD
    fi
}

function checkOutput() {
    if [ "$3" == "" ]; then
        out=`          eval "$1" 2>&1`
    else
        out=`echo $3 | eval "$1" 2>&1`
    fi
    if [ "$?" -ne 0 ]; then
        echo $out
        exit $2
    fi
}

function unmount_luks_partition()
{
    checkOutput "umount               $LOC_VAR          " $ERR_CRYPTSETUP_UNMOUNT_UNMOUNT
    checkOutput "cryptsetup luksClose $LOC_DIR          " $ERR_CRYPTSETUP_UNMOUNT_CLOSE
}

function create_luks_partition()
{
    umount_luks_partition
    
    checkOutput "mkdir      -p         $LOC_VAR         " $ERR_CRYPTSETUP_CREATE_MKDIR
    checkOutput "cryptsetup luksFormat $LOC_DEV         " $ERR_CRYPTSETUP_CREATE_FORMAT     $PASSWORD
    checkOutput "cryptsetup luksOpen   $LOC_DEV $LOC_DIR" $ERR_CRYPTSETUP_CREATE_OPEN       $PASSWORD
    checkOutput "mkfs.ext4             $LOC_MAP         " $ERR_CRYPTSETUP_CREATE_MKFS
    checkOutput "mount      -t ext4    $LOC_MAP $LOC_VAR" $ERR_CRYPTSETUP_CREATE_MOUNT
}

function mount_luks_partition()
{
    checkOutput "cryptsetup luksOpen   $LOC_DEV $LOC_DIR" $ERR_CRYPTSETUP_MOUNT_OPEN        $PASSWORD
    checkOutput "mount      -t ext4    $LOC_MAP $LOC_VAR" $ERR_CRYPTSETUP_MOUNT_MOUNT   
}

function handleCommand() {
    # Handle the first argument to script, one of start, stop, erase, restart, force-reload or status
    case $1 in
    setup)
        checkPassword
        create_luks_partition
        ;;

    mount)
        checkPassword
        mount_luks_partition
        ;;

    umount)
        unmount_luks_partition
        ;;

    *)
        echo "unknown command"
        exit $ERR_CRYPTSETUP_UNKNOWN
        ;;

    esac
}

handleCommand $1 $2

exit 0