#!/usr/bin/env sh

# qvm - Trivial management of 64 bit virtual machines with qemu.
#
# Written in 2016 by Franco Masotti/frnmst <franco.masotti@student.unife.it>
#
# To the extent possible under law, the author(s) have dedicated all 
# copyright and related and neighboring rights to this software to the public 
# domain worldwide. This software is distributed without any warranty.
#
# You should have received a copy of the CC0 Public Domain Dedication along 
# with this software. If not, see 
# <http://creativecommons.org/publicdomain/zero/1.0/>. 

help()
{
    cat <<-EOF
Usage: qvm [OPTION]
Trivial management of 64 bit virtual machines with qemu.

Options:
    -b, --backup                backup vhd
    -c, --create                create new vhd
    -d, --delete                delete vhd backup
        --delete-original       delete original vhd
    -h, --help                  print this help
    -i, --install               install img on vhd
    -r, --run                   run vm
        --run-nox               run vm without opening a graphical window
                                (useful for background jobs like SSH)

Only a single option is accepted.
Before running any virtual machine you must create a backup first.

CC0
Written in 2016 by Franco Masotti/frnmst <franco.masotti@student.unife.it>
EOF
}

unrecognized_option()
{
    printf "%s\n" "Try 'qvm --help' for more information"
} 1>&2-

backup()
{
    qemu-img create -f "$vhd_type" \
-b "$vhd_name" \
"$vhd_name".mod
}

create()
{
    qemu-img create -f "$vhd_type" \
"$vhd_name" \
"$vhd_size"
}

delete()
{
    rm "$vhd_name".mod
}

delete_original()
{
    rm "$vhd_name"
}

installs()
{
    qemu-system-x86_64 -m "$vm_memory" \
-enable-kvm \
-cdrom "$img_name" \
-boot order=d \
"$vhd_name" &
}

run()
{
    argc="$1"

    if [ -f "$vhd_name".mod ]; then
        qemu-system-x86_64 \
-m "$vm_memory" \
-enable-kvm \
-device e1000,netdev=user.0 \
-netdev user,\
id=user.0,hostfwd=tcp::"$host_port"-:"$guest_port",\
hostfwd=tcp::"$ssh_host_port"-:"$ssh_guest_port" \
-virtfs local,path="$shared_data_path",\
security_model=none,mount_tag="$mount_tag" \
-display "$argc" \
"$vhd_name".mod &
    else
        printf "Make a backup and an installation first.\n"
        exit 1
    fi
}

main()
{
    local argc="$1"
    local options="bcdhir"
    local long_options="backup,create,delete,delete-original\
,help,install,run,run-nox"
    local opts
    local opt

    [ -z "$argc" ] && argc="-r"

    opts="$(getopt --options $options --longoptions $long_options -- $argc)"

    [ $? -ne 0 ] && unrecognized_option && return 1

    eval set -- "$opts"

    # Source variables globally.
    . ./configvmrc

    for opt in $opts; do
        case "$opt" in
            -- )                                        ;;
            -b | --backup )             backup          ;;
            -c | --create )             create          ;;
            -d | --delete )             delete          ;;
                 --delete-original )    delete_original ;;
            -h | --help )               help            ;;
            -i | --install )            installs        ;;
            -r | --run )                run gtk         ;;
                 --run-nox )            run none        ;;
        esac
    done
}

main "$*"