#!/bin/bash

SUDO=""
# default versions
CDS_VERSION=4.0.0.0
EDGE_VERSION=4.0.0.0
# Overload versions, when they are passed as command line arguments
[ ! -z $1 ] && CDS_VERSION=$1
[ ! -z $2 ] && EDGE_VERSION=$2

URL="https://store.codesys.com/ftp_download/3S/LinuxSL/2302000005/${CDS_VERSION}/CODESYS%20Control%20for%20Linux%20SL%20${CDS_VERSION}.package"
EDGE_URL="https://store.codesys.com/ftp_download/3S/EdgeGatewayLinux/000120/${EDGE_VERSION}/CODESYS%20Edge%20Gateway%20for%20Linux%20${EDGE_VERSION}.package"

# check if this linux system is debian based
if ! which dpkg >/dev/zero; then
    echo "This install script only runs on debian based distributions"
    exit 1
fi

# check if we are running as root, or we have sudoers access to dpkg
if [ "$USER" != "root" ]; then
    if ! which sudo >/dev/zero; then
        echo "You are not running as root, and don't have sudo installed."
        exit 1
    fi
    echo "You are running as non-root user. We try to get sudo access to dpkg."
    if ! sudo dpkg --version >/dev/zero; then
        echo "You have no access to dpkg. Please rerun the script as root"
        exit 1
    fi
    SUDO="sudo"
fi

# check necessary tools
if ! which wget >/dev/zero; then
    echo "We need the tool 'wget' to download the CODESYS package."
    echo "You may try:"
    echo "  apt-get install wget"
    exit 1
fi

if ! which unzip >/dev/zero; then
    echo "We need the tool 'unzip' to unpack the CODESYS package."
    echo "You may try:"
    echo "  apt-get install unzip"
    exit 1
fi

# check if /lib64 is available
if ! -d /lib64; then
    echo "Seems that you are not running on a traditional multi arch system."
    echo "As a workaround, you can link /lib to /lib64."
    echo "ln -s /lib /lib64"
fi

# check availability of ipv4, and try to install xinetd forwarding if not
ipv4=$(ip -4 addr list scope global)
ipv6=$(ip -6 addr list scope global)

if [ -z "${ipv4}" -a ! -z "${ipv6}" ]; then
    echo "You are running on an ipv6 only host. CODESYS doesn't support this, yet."
    echo "So we try to install an ipv6 forwarding, using xinetd."
    # check if xinetd is installed
    if [ ! -d /etc/xinetd.d ]; then
        echo "We need the tool 'xinetd' to tunnel between ipv4 and ipv6"
        echo "You may try:"
        echo "  apt-get install xinetd"
        exit 1
    fi
    address=$(ip -6 addr list scope global dev eth0 | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)
    cat <<EOF >/etc/xinetd.d/codesys-ipv6
service codesys-tcp
{
    flags           = IPv6
    disable         = no
    type            = UNLISTED
    socket_type     = stream
    protocol        = tcp
    user            = nobody
    wait            = no
    redirect        = 127.0.0.1 11740
    port            = 11740
    bind            = ${address}
}
service codesys-gw
{
    flags           = IPv6
    disable         = no
    type            = UNLISTED
    socket_type     = stream
    protocol        = tcp
    user            = nobody
    wait            = no
    redirect        = 127.0.0.1 1217
    port            = 1217
    bind            = ${address}
}
service codesys-edge
{
    flags           = IPv6
    disable         = no
    type            = UNLISTED
    socket_type     = stream
    protocol        = tcp
    user            = nobody
    wait            = no
    redirect        = 127.0.0.1 11743
    port            = 11743
    bind            = ${address}
}
EOF
    systemctl reload xinetd
fi

# start installation
if [ -z "${TRY_RUN}" ]; then
    # download and install the edge package
    [ ! -f /tmp/edge.package ] && wget --output-document=/tmp/edge.package ${EDGE_URL}
    (
        unzip -p /tmp/edge.package '*.deb' >/tmp/edge.deb &&
            ${SUDO} dpkg -i /tmp/edge.deb
    )
    # download and install the control package
    [ ! -f /tmp/codesys.package ] && wget --output-document=/tmp/codesys.package ${URL}
    (
        unzip -p /tmp/codesys.package '*codemeter*.deb' >/tmp/codemeter.deb &&
            ${SUDO} dpkg -i /tmp/codemeter.deb
        unzip -p /tmp/codesys.package '*codesyscontrol*.deb' >/tmp/codesys.deb &&
            ${SUDO} dpkg -i /tmp/codesys.deb
    )
fi