#!/bin/bash
#

#RESULT_POSSIBLE=("init","start","start-backup","create","backup","restore")

VERSION=0.5
MAIN_LOCATION="$HOME/virtual-machine/"


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

    echo "Do you want to forward ssh port (y/n) "
    read entry

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

    mkdir -p conf
    echo "
NAME=\"$NAME\"
VMHOSTNAME=\"\$NAME-vm\"
NPROC=$NPROC
MEMORY=\"$MEMORY\"
FORWARD=\"$FORWARD\"
LOCATION=\"\$NAME-sandbox/\"
" > conf/$NAME-vm_var.sh
    chmod +x conf/$NAME-vm_var.sh

}

START() {
    qemu-system-x86_64 \
        -enable-kvm \
        -cpu host \
        -smp $NPROC \
        -net nic \
        -net user$FORWARD,hostname=$VMHOSTNAME \
        -m $MEMORY \
        -drive file=${MAIN_LOCATION}${LOCATION}${VMHOSTNAME}.cow \
        -daemonize

    sleep 5

    ssh -o "StrictHostKeyChecking no" -o "UserKnownHostsFile=/dev/null" primardj@localhost -p 10022
}

START-BACKUP() {
    qemu-system-x86_64 \
        -enable-kvm \
        -cpu host \
        -smp $NPROC \
        -net nic \
        -net user$FORWARD,hostname=$VMHOSTNAME \
        -m $MEMORY \
        -drive file=${MAIN_LOCATION}${LOCATION}${VMHOSTNAME}.cow.backup \
        -daemonize

    sleep 5

    #ssh -o "StrictHostKeyChecking no" -o "UserKnownHostsFile=/dev/null" primardj@localhost -p 10022
}

CREATE() {

    if [[ ! -f ${MAIN_LOCATION}${LOCATION}${VMHOSTNAME}.cow ]]
    then
        echo "ceate directory ${MAIN_LOCATION}${LOCATION}"
        mkdir -p ${MAIN_LOCATION}${LOCATION}
        qemu-img create -f qcow2 ${MAIN_LOCATION}${LOCATION}${VMHOSTNAME}.cow 40G
    fi


    qemu-system-x86_64 \
        -enable-kvm \
        -cpu host \
        -smp $NPROC \
        -net nic \
        -net user$FORWARD,hostname=$VMHOSTNAME \
        -m $MEMORY \
        -drive file=${MAIN_LOCATION}${LOCATION}${VMHOSTNAME}.cow \
        -boot d \
        -drive file="$1",media=cdrom
}

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


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


if [ $# -lt 2 ]
then
    echo "Error, not enough args"
    exit 1
fi

cd "$( dirname "$( readlink -f "$0" )" )"

if [[ ! -f conf/$1-vm_var.sh ]]
then
    INIT $1
fi

source conf/$1-vm_var.sh


if [ "$2" == "start" ]
then
    echo "starting VM $1"
    START
elif [ "$2" == "start-backup" ]
then
    echo "starting VM rescue"
    START-BACKUP
elif [ "$2" == "backup" ]
then
    echo "backup VM"
    BACKUP
elif [ "$2" == "restore" ]
then
    echo "restore VM"
    RESTORE
elif [ "$2" == "create" ]
then
    echo "creating VM"
    if [[ $# == 3 ]]
    then
        echo "using image disk $3"
        CREATE $3
    else
        echo "Error, no image defined."
    fi
elif [[ "$2" == "version" ]]
then
    echo "script lancement vm version v.$VERSION"
else
    echo "commande $2 inconnue"
fi