#!/bin/bash

set -eu
set -o noglob

fatal() {
    local MSG="${1}"
    >&2 echo "[!] ${MSG}"
    exit 1
}

info() {
    local MSG="${1}"
    echo "[-] ${MSG}"
}

usage() {
    echo "$(basename $0) backup-directory"
    echo "  backup-directory - path to backup directory"
    exit 1
}

move() {
    local FILE="${1}"
    local DIRNAME=$(dirname ${FILE})
    [[ -f $FILE || -L $FILE ]] || return 0
    
    mkdir -p "${BACKUP_DIR}/${DIRNAME##/}/"
    mv ${FILE} "${BACKUP_DIR}/${DIRNAME##/}/"

    info "Original file ${FILE} was moved to ${BACKUP_DIR}/${DIRNAME##/}/"
}

write() {
    local FILE="${1}"
    local CONTENT="${2}"
    local CHMOD="${3:-}"

    info "Creating file ${FILE}"
    move ${FILE}

    echo "${CONTENT}" > ${FILE}

    [[ -n ${CHMOD} ]] && chmod ${CHMOD} ${FILE} || :
}

declare -r BACKUP_DIR=$(realpath -sm "${1:-}" -q || :)

[[ -z ${BACKUP_DIR} ]] && usage
[[ -e ${BACKUP_DIR} ]] || fatal "Does not exist: ${BACKUP_DIR}"
[[ -d ${BACKUP_DIR} ]] || fatal "Is not a directory: ${BACKUP_DIR}"
[[ -z "$(ls -A1 ${BACKUP_DIR})" ]] || fatal "Directory is not empty: ${BACKUP_DIR}"

declare -r ENI_IFUP_DIR="/etc/network/if-up.d"
declare -r ENI_IFDOWN_DIR="/etc/network/if-down.d"
declare -r ENI_IFUP_FILE="${ENI_IFUP_DIR}/phoenix-ga-netinit"
declare -r ENI_IFDOWN_FILE="${ENI_IFDOWN_DIR}/phoenix-ga-netinit"

declare -r ENI_IFUP_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u

/usr/sbin/phoenix-ga netinit --configure-iface $IFACE

exit 0
EOF
)

declare -r ENI_IFDOWN_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u

/usr/sbin/phoenix-ga netinit --deconfigure-iface $IFACE

exit 0
EOF
)

configure_eni () {
    [[ -d ${ENI_IFUP_DIR} && -d ${ENI_IFDOWN_DIR} ]] && info "ifupdown detected" || return 0

    write "${ENI_IFUP_FILE}" "${ENI_IFUP_CONTENT}" 750
    write "${ENI_IFDOWN_FILE}" "${ENI_IFDOWN_CONTENT}" 750
}

declare -r SYSCONFIG_NS_DIR="/etc/sysconfig/network-scripts"
declare -r SYSCONFIG_ETH0_CFG_FILE="${SYSCONFIG_NS_DIR}/ifcfg-eth0"
declare -r SYSCONFIG_ETH1_CFG_FILE="${SYSCONFIG_NS_DIR}/ifcfg-eth1"
declare -r SYSCONFIG_NETINIT_FILE="${SYSCONFIG_NS_DIR}/phoenix-ga-netinit"
declare -r SYSCONFIG_IFUP_LOCAL_FILE="/sbin/ifup-local"
declare -r SYSCONFIG_IFDOWN_LOCAL_FILE="/sbin/ifdown-local"
declare -r SYSCONFIG_FLOPPY_MODULES_FILE="/etc/sysconfig/modules/floppy.modules"

declare -r SYSCONFIG_ETH0_CFG_CONTENT=$(cat <<'EOF'
DEVICE=eth0
ONBOOT=yes
NM_CONTROLLED=no
EOF
)

declare -r SYSCONFIG_ETH1_CFG_CONTENT=$(cat <<'EOF'
DEVICE=eth1
ONBOOT=yes
NM_CONTROLLED=no
EOF
)

declare -r SYSCONFIG_NETINIT_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u

case "$1" in
    'up')
        /usr/sbin/phoenix-ga netinit --configure-iface "$2"
    ;;
    'down')
        /usr/sbin/phoenix-ga netinit --deconfigure-iface "$2"
    ;;
esac

exit 0
EOF
)

declare -r SYSCONFIG_IFUP_LOCAL_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u
exec /etc/sysconfig/network-scripts/phoenix-ga-netinit "up" "$1"
EOF
)

declare -r SYSCONFIG_IFDOWN_LOCAL_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u
exec /etc/sysconfig/network-scripts/phoenix-ga-netinit "down" "$1"
EOF
)

declare -r SYSCONFIG_FLOPPY_MODULES_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u

/sbin/modprobe floppy

exit 0
EOF
)

configure_sysconfig () {
    [[ -d ${SYSCONFIG_NS_DIR} ]] && info "CentOS-based sysconfig detected" || return 0

    write "${SYSCONFIG_ETH0_CFG_FILE}" "${SYSCONFIG_ETH0_CFG_CONTENT}"
    write "${SYSCONFIG_ETH1_CFG_FILE}" "${SYSCONFIG_ETH1_CFG_CONTENT}"
    write "${SYSCONFIG_NETINIT_FILE}" "${SYSCONFIG_NETINIT_CONTENT}" 750
    write "${SYSCONFIG_IFUP_LOCAL_FILE}" "${SYSCONFIG_IFUP_LOCAL_CONTENT}" 750
    write "${SYSCONFIG_IFDOWN_LOCAL_FILE}" "${SYSCONFIG_IFDOWN_LOCAL_CONTENT}" 750
    write "${SYSCONFIG_FLOPPY_MODULES_FILE}" "${SYSCONFIG_FLOPPY_MODULES_CONTENT}"
}

declare -r SYSCONFIG_SUSE_ETH0_CFG_FILE="/etc/sysconfig/network/ifcfg-eth0"
declare -r SYSCONFIG_SUSE_ETH1_CFG_FILE="/etc/sysconfig/network/ifcfg-eth1"
declare -r SYSCONFIG_SUSE_NETINIT_FILE="/etc/sysconfig/network/scripts/phoenix-ga-netinit"

declare -r SYSCONFIG_SUSE_ETH0_CFG_CONTENT=$(cat <<'EOF'
DEVICE=eth0
STARTMODE=auto
NM_CONTROLLED=no
POST_UP_SCRIPT="compat:suse:phoenix-ga-netinit"
POST_DOWN_SCRIPT="compat:suse:phoenix-ga-netinit"
EOF
)

declare -r SYSCONFIG_SUSE_ETH1_CFG_CONTENT=$(cat <<'EOF'
DEVICE=eth1
STARTMODE=auto
NM_CONTROLLED=no
POST_UP_SCRIPT="compat:suse:phoenix-ga-netinit"
POST_DOWN_SCRIPT="compat:suse:phoenix-ga-netinit"
EOF
)

declare -r SYSCONFIG_SUSE_NETINIT_CONTENT=$(cat <<'EOF'
#!/bin/sh
set -u

# The script is executed as
#   $script $interface $interface -o $action
# with the pre-up, post-up, pre-down, post-down actions
# corresponding with the variable name.
#
# See details in 'man 5 ifcfg'

>/dev/null 2>&1 blockdev --flushbufs /dev/fd0

case "$4" in
    'post-up')
        /usr/sbin/phoenix-ga netinit --configure-iface "$1"
    ;;
    'post-down')
        /usr/sbin/phoenix-ga netinit --deconfigure-iface "$1"
    ;;
esac

exit 0
EOF
)

configure_sysconfig_opensuse() {
    [[ -d "/etc/sysconfig/network/scripts/" ]] && info "openSUSE-based sysconfig detected" || return 0

    write "${SYSCONFIG_SUSE_ETH0_CFG_FILE}" "${SYSCONFIG_SUSE_ETH0_CFG_CONTENT}"
    write "${SYSCONFIG_SUSE_ETH1_CFG_FILE}" "${SYSCONFIG_SUSE_ETH1_CFG_CONTENT}"
    write "${SYSCONFIG_SUSE_NETINIT_FILE}" "${SYSCONFIG_SUSE_NETINIT_CONTENT}" 750
}

configure_eni
configure_sysconfig
configure_sysconfig_opensuse