#!/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/>. 

check_dependencies()
{
    command -V qemu-system-x86_64 \
        && command -V qemu-img \
        && command -V ssh \
        && command -V vncviewer
}

attach()
{
    local place="${1}"
    local display="${2}"
    local address=''

    [ "${place}" = 'remote' ] && address="${HOST_IP_ADDRESS}" || address='127.0.0.1'
    [ -n "${place}" ] && [ "${display}" != 'vnc' ] && ssh -p "${SSH_HOST_PORT}" -l "${SSH_GUEST_USERNAME}" "${address}"
    if [ "${display}" = 'vnc' ]; then
        # Forward "${address}":5900 to localhost:5901 through SSH.
        ssh -N -f -L 5901:127.0.0.1:5900 -l "${HOST_USERNAME}" "${address}"
        # Connect to port 5901.
        vncviewer 127.0.0.1:1
    fi
}

backup()
{
    qemu-img create -f qcow2 -b "${VHD_NAME}" "${VHD_NAME}".mod
}

create()
{
    qemu-img create -f qcow2 "${VHD_NAME}" "${VHD_SIZE}"
}

delete()
{
    local vhd_type="${1}"
    local vhd=''

    [ "${vhd_type}" = 'origin' ] && vhd="${VHD_NAME}" || vhd=""${VHD_NAME}".mod"
    rm "${vhd}"
}

installs()
{
    local display="${1}"
    local enable_vnc=''

    [ "${display}" = 'vnc' ] && enable_vnc='-monitor pty -vnc 127.0.0.1:0'

    qemu-system-x86_64 -m "${MEMORY}" \
        -device e1000,netdev=user.0 \
        -netdev user,id=user.0,\
hostfwd=tcp::"${SSH_HOST_PORT}"-:"${SSH_GUEST_PORT}" \
        -enable-kvm \
        ${enable_vnc} \
        -smp ${NUMBER_OF_CORES} \
        -cdrom "${IMG_NAME}" \
        -boot order=d \
        "${VHD_NAME}" &
}

mkdir_shared()
{
    mkdir -p "${SHARED_DATA_PATH}"
}

run()
{
    local display="${1}"
    local vhd_type="${2}"
    local vhd=''
    local enable_vnc=''

    [ "${display}" = 'vnc' ]  \
        && display='none' \
        && enable_vnc="-monitor pty -vnc 127.0.0.1:0"
    [ "${vhd_type}" = 'origin' ] && vhd="${VHD_NAME}" || vhd=""${VHD_NAME}".mod"

    # Adds ALSA audio support.
    export QEMU_AUDIO_DRV=alsa

    # No spaces between the parameters of each option.
    qemu-system-x86_64 \
        -m "${MEMORY}" \
        -enable-kvm \
        ${enable_vnc} \
        -device e1000,netdev=user.0 \
        -netdev user,id=user.0,\
hostfwd=tcp::"${HOST_PORT_1}"-:"${GUEST_PORT_1}",\
hostfwd=tcp::"${HOST_PORT_2}"-:"${GUEST_PORT_2}",\
hostfwd=tcp::"${SSH_HOST_PORT}"-:"${SSH_GUEST_PORT}" \
        -virtfs local,path="${SHARED_DATA_PATH}",security_model=passthrough,mount_tag="${MOUNT_TAG}" \
        -smp ${NUMBER_OF_CORES} \
        -soundhw ac97 \
        -display "${display}" \
        -drive file="${vhd}" &
}

# Start and connect to a remote QVM instance hosted on a different machine.
run_remote_instance()
{
    local display="${1}"

    if [ -z "$(ssh -l "${HOST_USERNAME}" "${HOST_IP_ADDRESS}" "pgrep qemu")" ]; then
        if [ "${display}" = 'vnc' ]; then
            ssh -p ${SSH_EXPOSED_PORT} -l "${HOST_USERNAME}" "${HOST_IP_ADDRESS}" \
                "cd "${HOST_QVM_SCRIPT_DIRECTORY}" && ./qvm --run --vnc" &
        else
            ssh -p ${SSH_EXPOSED_PORT} -l "${HOST_USERNAME}" "${HOST_IP_ADDRESS}" \
                "cd "${HOST_QVM_SCRIPT_DIRECTORY}" && ./qvm --run --nox" &
        fi
        sleep ${SECONDS_BEFORE_CONNECTION_ATTEMPT}
    fi

    attach 'remote' "${display}"
}

program_name="${0}"
local_path="${program_name%/qvm}"
# Source variables globally.
. "${local_path}"/configvmrc
. "${local_path}"/fbopt