#!/usr/bin/env bash

# shellcheck disable=SC2155
readonly PROGNAME=$(basename "${0}")
# shellcheck disable=SC2155
readonly PROGDIR=$(readlink -m "$(dirname "${0}")")
# shellcheck disable=SC2124
readonly ARGS=$@

# Change this to wherever you install the libraries
readonly LIBDIR="/usr/local/lib/evobackup"

source "${LIBDIR}/main.sh"

show_version() {
    cat <<END
${PROGNAME} version ${VERSION}

Copyright 2024 Evolix <info@evolix.fr>,
               Jérémy Lecour <jlecour@evolix.fr>.

${PROGNAME} comes with ABSOLUTELY NO WARRANTY.  This is free software,
and you are welcome to redistribute it under certain conditions.
See the GNU General Public License v3.0 for details.
END
}
show_help() {
    cat <<END
${PROGNAME} helps managing evobackup scripts

Options
 -h, --help                  print this message and exit
 -V, --version               print version and exit
     --jail-init-commands    print jail init commands
     --copy-template=PATH    copy the backup template to PATH
END
}

jail_init_commands() {
    if [ ! -f /root/.ssh/id_ed25519.pub ]; then
        ssh-keygen -t ed25519 -f /root/.ssh/id_ed25519 -N ''
        echo ""
    fi

    SSH_KEY=$(cat /root/.ssh/id_ed25519.pub)
    SERVER_NAME=$(hostname -s)
    if [ "$(uname -s)" = "OpenBSD" ]; then
        SERVER_IP=$(ifconfig egress | grep "inet " | head -1 | awk '{ print $2}')
    else
        SERVER_IP=$(curl -4 https://ifconfig.me 2> /dev/null || hostname -I | awk '{ print $1}')
    fi

    echo "Copy-paste those lines on backup server(s) :"
    echo "----------"
    echo "SERVER_NAME=${SERVER_NAME}"
    echo "SERVER_IP=${SERVER_IP}"
    echo "echo '${SSH_KEY}' > /root/\${SERVER_NAME}.pub"
    echo "bkctld init \${SERVER_NAME}"
    echo "bkctld key \${SERVER_NAME} /root/\${SERVER_NAME}.pub"
    echo "bkctld ip \${SERVER_NAME} \${SERVER_IP}"
    echo "bkctld start \${SERVER_NAME}"
    echo "bkctld status \${SERVER_NAME}"
    echo "grep --quiet --extended-regexp \"^\\s?NODE=\" /etc/default/bkctld && bkctld sync \${SERVER_NAME}"
    echo "----------"
}

copy_template() {
    dest_path=${1}
    dest_dir="$(dirname "${dest_path}")"

    if [ -e "${dest_path}" ]; then
        printf "Path for new evobackup script '%s' already exists.\n" "${dest_path}" >&2
        exit 1
    elif [ ! -e "${dest_dir}" ]; then
        printf "Parent directory '%s' doesn't exist. Create it first.\n" "${dest_dir}" >&2
        exit 1
    else
        if cp "${LIBDIR}/zzz_evobackup.sh" "${dest_path}"; then
            chmod 750 "${dest_path}"

            sed -i "s|@COMMAND@|${PROGDIR}/${PROGNAME} ${ARGS}|" "${dest_path}"
            sed -i "s|@DATE@|$(date --iso-8601=seconds)|" "${dest_path}"
            sed -i "s|@VERSION@|${VERSION}|" "${dest_path}"

            printf "New evobackup script has been saved to '%s'.\n" "${dest_path}"
            printf "Remember to customize it (mail notifications, backup servers…).\n"
            exit 0
        fi
    fi
}

main() {
    # If no argument is provided, print help and exit
    # shellcheck disable=SC2086
    if [ -z ${ARGS} ]; then
        show_help
        exit 0
    fi
    # Parse options, based on https://gist.github.com/deshion/10d3cb5f88a21671e17a
    while :; do
        case ${1:-''} in
            -V|--version)
                show_version
                exit 0
                ;;
            -h|--help)
                show_help
                exit 0
                ;;
            --jail-init-commands)
                jail_init_commands
                exit 0
                ;;
            --copy-template)
                # copy-template option, with value separated by space
                if [ -n "$2" ]; then
                    copy_template "${2}"
                    shift
                else
                    printf "'%s' requires a non-empty option argument.\n" "--copy-template" >&2
                    exit 1
                fi
                ;;
            --copy-template=?*)
                # copy-template option, with value separated by =
                copy_template "${1#*=}"
                ;;
            --copy-template=)
                # copy-template option, without value
                printf "'%s' requires a non-empty option argument.\n" "--copy-template" >&2
                exit 1
                ;;
            --)
                # End of all options.
                shift
                break
                ;;
            -?*|[[:alnum:]]*)
                # ignore unknown options
                printf "unknown option '%s'.\n" "${1}" >&2
                exit 1
                ;;
            *)
                # Default case: If no more options then break out of the loop.
                break
                ;;
        esac

        shift
    done
}

main ${ARGS}