#!/usr/bin/bash
#

#RESULT_POSSIBLE=("init","list","start","start_backup","create","backup","restore","suppr")

# Constante d'éxecutions.
Version="0.7.0-developpement_02-01-2021"
USAGE="vm-start [PARAMETTER] [ NAME COMMAND [OPTION] ]

Script to manage virtual machine easily.

NAME is the name of the virtual machine to use.

PARAMETTER available
    -h, --help              Print this help and exit
    -v, --version           Print the version of this program and quit
    -l, --list              Print the list of all availables machines and quit

COMMAND available
    init                    Create the conf file in conf/NAME_var.sh
    start                   Start the virtual machine using the variabes in conf/NAME_var.sh
    start-backup            Start the virtual machine using the backup volume if it exists.
    create                  Create the virtual machine using the conf in conf/NAME_var.sh
    backup                  Create a backup file for the vm
    restore                 Restore the virtual machine using to backup file
    suppr                   Suppr all data related to the virtual machine other than the conf file.
    suppr-all               Suppr all data related to the vm even the conf file


OPTION available
    nproc=<nb proc>         Def the number of proc of the vm
    memory=<mem>            Def the qty of memory allocated to the vm
    size=<size>             Def the size that should be allocated by create #TODO
    uefi                    Select if there will be an UEFI by default.
                            can be either set or unset. By default is unset.
    options=<option>        additinal options to give to qemu. By default is
                            -display gtk -vga qxl
    create_disk=<loc_disk>  Def a create disk to boot on. Is necessary for using create, or need the variable INSTALLATION_DISK_LOCATION to be set.
    net=nat:id                 Add a nat connection to the vm. By default there is already one.
    net=br:<br-id>          Connect the vm to the bridge <br-id>. Please use the script set-tap.sh as root to create the bridge. in the conf file, a mac field have to be set. for two vm to connect togethers, their mac addresses on the same network have to be differents.
    net=none                The vm will have no network interface
"

MAIN_LOCATION="$HOME/virtual_machine"
# if MAIN_LOCATION doesn't exists, create the folder.
if [ -f "$MAIN_LOCATION" ]
then
    mkdir "$MAIN_LOCATION" || exit 0 #Exit in case the folder can't be created.
    echo "$MAIN_LOCATION created to contain all virtual machines."
fi

OPTION="-display gtk \
    -usbdevice tablet"

        # other options choices
        #
        #-display sdl
        #-vga qxl
        #-usbdevice tablet \


list() {
    echo "this is the list of all vm actually configured."
    for vm in $(ls conf); do
        echo "${vm%-vm_var.sh}"
    done
    exit 0
}

HELP() {
    echo "$USAGE"
    exit 0
}

INIT() {
    echo "INIT for vm $1"
    NAME="$1"
    read -p "How many proccessor will you use ? " -r NPROC
    read -p "How much memory will you need ? " -r MEMORY

    # from now on, ssh port forward to choose while exec the script.

    #read -p "Do you want to forward ssh port (y/n) " -r entry

    #if echo "$entry" | grep -q "^[yY]$" 
    #then
    #    FORWARD=",hostfwd=tcp::10022-:22" # forward VM 22 port to Host 10022 
    #fi

    mkdir -p conf
    cat << EOF > "conf/$NAME-vm_var.sh"
NAME="${NAME}"
VMHOSTNAME="\${NAME}-vm"
VMDRIVE="\${VMHOSTNAME}.cow"
NPROC="${NPROC}"
MEMORY="${MEMORY}"
FORWARD="${FORWARD}"
LOCATION="\${NAME}-sandbox"
mac="00:00:00:00:00:00"
EOF
    chmod +x "conf/$NAME-vm_var.sh"

}

start_the_vm() {

    if [ "${network}" == "" ]
    then
        network="-net nic \
            -net user${FORWARD},hostname=${VMHOSTNAME}"
    fi

    qemu-system-x86_64 \
        -enable-kvm \
        -cpu host \
        -smp "$NPROC" \
        $network \
        -m "$MEMORY" \
        -drive file="${MAIN_LOCATION}/${LOCATION}/${VMDRIVE}",index=2,id=maindrive,media=disk \
        $OPTION

}

START() {
    start_the_vm

}

START_BACKUP() {
    VMDRIVE="${VMDRIVE}.backup"
    start_the_vm

}

CREATE() {

    if [ -z "${SIZE+x}" ] 
    then
        SIZE="40G"
    fi

    if [ ! -f "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow" ]
    then
        echo "create directory ${MAIN_LOCATION}/${LOCATION}/"
        mkdir -p "${MAIN_LOCATION}/${LOCATION}/"
        qemu-img create -f qcow2 "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow" "$SIZE"
    fi

    if [ "${UEFI}" == "set" ]
    then
        echo "create UEFIVAR"
        if [ ! -f "${MAIN_LOCATION}/${LOCATION}/OVMF_VARS.4m.fd" ]
        then
            cp /usr/share/edk2/x64/OVMF_VARS.4m.fd "${MAIN_LOCATION}/${LOCATION}"
        else
            echo "INFO, UEFIVAR already existing"
        fi
    fi

    OPTION="$OPTION \
        -boot d \
        -drive file=$1,if=none,media=cdrom,id=drive-cd1 \
        -device ide-cd,drive=drive-cd1,id=cd1,bootindex=1"

    start_the_vm


}

RESTORE() {
    read -p "Are you sure you want to restore the rescue? (y/N) " -r entry
    if echo "$entry" | grep -q "^[yY]$"
    then
        cp -i "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow.backup" "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow"
        echo "Done"
    fi
}


BACKUP() {
    read -p "Are you sure you want to backup the volume? If you continue the previous backup will be lost (y/N) " -r entry
    if echo "$entry" | grep -q "^[yY]$"
    then
        cp -i "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow" "${MAIN_LOCATION}/${LOCATION}/${VMHOSTNAME}.cow.backup"
        echo "Done"
    fi
}

SUPPRESS() {
    read -p "Are you sure you want to delete all data relative to the vm $1? (y/N)" -r entry
    if echo "$entry" | grep -q "^[yY]$"
    then 
        rm -Ri "${MAIN_LOCATION}/${LOCATION}"
    fi
}


suppress_all() {
    read -p "Are you sure you want to delete all data relative to the vm $1 even conf file? (y/N)" -r entry
    if echo "$entry" | grep -q "^[yY]$"
    then 
        rm -i conf/$1-vm_var.sh
        rm -Ri "${MAIN_LOCATION}/${LOCATION}"
    fi
}

set_uefi() {
    UEFI="set"
    OPTION="${OPTION} \
        -drive if=pflash,format=raw,readonly=on,file=/usr/share/edk2/x64/OVMF_CODE.4m.fd \
        -drive if=pflash,format=raw,file=${MAIN_LOCATION}/${LOCATION}/OVMF_VARS.4m.fd"

}

set_net() {
    case "${1%:*}" in
        "nat")
            echo "add the interface ${1#*:}"
            network="${network} \
                -netdev user,id=${1#*:} \
                -device virtio-net,netdev=${1#*:}"
            ;;
        "br")
            echo "add bridge ${1#*:}"
            if [ "${mac}" == "" ]
            then
                echo "error, no mac set"
                exit 1
            fi
            network="${network} \
                -netdev bridge,id=${1#*:} \
                -device virtio-net,netdev=${1#*:},mac=${mac}"
            ;;
        "none")
            echo "no interface will be connected."
            network="-nic none"
            ;;
        *)
            echo "type ${1%:*} not known, it should be either nat, br or none" >&2
            exit 1
            ;;
    esac
}



# change active directory to became the one is stored vm-start. In case it is impossible, quit.
cd "$( dirname "$( readlink -f "$0" )" )" || exit

# gère les paramètres
for i in "$@"; do
    case "$i" in
        "-h" | "--help")
            HELP
            ;;
        "-v" | "--version")
            echo "vm-start ${Version}"
            exit 0
            ;;
        "-l" | "--list")
            list
            ;;
    esac
done


# verifie au moins assez d'options pour utiliser le programme.

if [ $# -lt 2 ]
then
    echo "Error, not enough args" >&2
    HELP
fi

# vérifie que le dossier pour stocker les vms existe & change le dossier actif pour qu'il soit cellui du lanceur.

mkdir -p "$MAIN_LOCATION"

# Vérifie qu'il y ait bien un fichier de config pour la vm que l'on tente de démarer dans la cas contraire en génére un.
# possibilitée de générer à nouveau le fichier de config avec vm-start nom-vm init

if [ ! -f "conf/$1-vm_var.sh" ]
then
    echo "no config file found. creating one in conf/${1}-vm_var.sh"
    INIT "$1"

    if [ "$2" == "init" ]
    then
        # Exit, it is the end of the program.
        exit 0 
    fi
fi

#Vérifie si l'option UEFI est set dans le fichier de config. Si oui l'ajoutte aux options.

. "conf/$1-vm_var.sh"

for (( i=3; i<=$#; i++)); do
    case "${!i%=*}" in
        "nproc")
            NPROC="${!i#*=}"
            ;;
        "memory")
            MEMORY="${!i#*=}"
            ;;
        "size")
            SIZE="${!i#*=}"
            ;;
        "uefi")
            set_uefi
            ;;
        "create_disk")
            INSTALLATION_DISK_LOCATION="${!i#*=}"
            ;;
        "net")
            param="${!i#*=}"
            set_net "${param}"
            ;;
    esac
done


if [ "${UEFI}" == "yes" ]
then
    set_uefi
fi


case "$2" in
    "start")
        echo "starting VM $1"
        START
        ;;
    "start-backup")
        echo "starting VM rescue"
        START_BACKUP
        ;;
    "backup")
        echo "backup VM"
        BACKUP
        ;;
    "restore")
        echo "restore backup"
        RESTORE
        ;;
    "create")
        echo "creating VM"
        if [ ! "${INSTALLATION_DISK_LOCATION}" == "" ]
        then
            echo "using image disk ${INSTALLATION_DISK_LOCATION}"
            CREATE "${INSTALLATION_DISK_LOCATION}"
        else
            echo "Error, no image defined." >&2
        fi
        ;;
    "suppr")
        echo "suppressing all data of the vm $1"
        SUPPRESS "$1"
        ;;
    "suppr-all")
        echo "suppressing all data and conf file of the vm $1"
        suppress_all "$1"
        ;;
    "init")
        echo "Init volume $1"
        INIT "$1"
        ;;
    *)
        echo "commande $2 inconnue" >&2
        HELP
esac