#!/bin/bash
#  $HeadURL: https://svn.pasta.freemyip.com/main/miniade/trunk/bin/nop-sh $ $LastChangedRevision: 10133 $

#  Modules
. $(miniade) || { echo "${0##*/}: ERROR: miniade failed (hint: run 'miniade' to see error)" >&2; exit 1; }

#  Configurable stuff
ZONES="$(ls /etc/bind | sed -n 's/^db\.//p' | fgrep -vx -e 0 -e 127 -e 255 -e empty -e local -e rpz-remote | paste -s -d' ')"
FREEZE=false

#  Other globals

main()
{
    local MY_ARGS
    local PROGNAME

    #  Defaults for options

    #  Process options
    miniade_process_options --help-handler=help MY_ARGS "$@" && set -- "${MY_ARGS[@]}"

    #  Process arguments
    [ $# = 0 ] || miniade_bad_usage

    #  Sanity checks and derivations
    miniade_get_progname PROGNAME
    [ -f $HOME/.${PROGNAME}rc ] || touch $HOME/.${PROGNAME}rc
    bash -c ". $HOME/.${PROGNAME}rc" || miniade_error "~/.${PROGNAME}rc: not loadable (hint: does it contain a bash syntax error?)"
    ZONES=()
    FREEZE=
    . $HOME/.${PROGNAME}rc
    [ ${#ZONES[*]} -gt 0 ] || miniade_error "ZONES: unset or empty (hint: set ZONES=( ... ) in ~/.${PROGNAME}rc)"
    for WANTED_ZONE in rpz-local rpz-remote; do 
        FOUND=false
        for ZONE in "${ZONES[@]}"; do
            if [ "X$WANTED_ZONE" = "X$ZONE" ]; then
                FOUND=true
                break
            fi
        done
        $FOUND || miniade_error "$WANTED_ZONE: not in zone list (hint: add '$WANTED_ZONE' to ZONES in ~/.${PROGNAME}rc)"
    done
    [[ $FREEZE =~ ^(true|false)$ ]] || miniade_error "FREEZE: unset or invalid (hint: set FREEZE=true or FREEZE=false in ~/.${PROGNAME}rc)"
    { ! $FREEZE; } || miniade_error "freezing is currently not support (hint: set FREEZE=false in ~/.${PROGNAME}rc)"

    #  Guts
    INIT_NAMED_CONF_LOCAL_FLAG=false
    for ZONE in "${ZONES[@]}"; do
        if [ ! -f /etc/bind/db.$ZONE ]; then
             miniade_warning "db.$ZONE: does not exist; initialising ..."
             init_zone $ZONE
             INIT_NAMED_CONF_LOCAL_FLAG=true
        fi
    done
    if $INIT_NAMED_CONF_LOCAL_FLAG; then
        miniade_warning "named.conf.local: initialsing ..."
        init_named_conf_local
    fi

    { ! $FREEZE; } || freeze_or_thaw freeze

    miniade_debug 10 "main: making backup for comparison purposes ..."
    for ZONE in "${ZONES[@]}"; do
        cp /etc/bind/db.$ZONE /tmp/
    done

    miniade_debug 10 "main: editing ..."
    for ZONE in "${ZONES[@]}"; do
        ${EDITOR:-vi} /tmp/db.$ZONE
    done

    miniade_debug 10 "main: checking for modifications ..."
    SAME_FLAG=true
    for ZONE in "${ZONES[@]}"; do
        cmp -s /etc/bind/db.$ZONE /tmp/db.$ZONE || { SAME_FLAG=false; break; }
    done
    if $SAME_FLAG; then
        miniade_info "no changes made"
        { ! $FREEZE; } || freeze_or_thaw thaw
        return 0
    fi

    miniade_debug 10 "main: copying modified temporary copies back ..."
    for ZONE in "${ZONES[@]}"; do
        cat /tmp/db.$ZONE > /etc/bind/db.$ZONE
    done

    miniade_debug 10 "main: bumping serial number ..."
    TS=$(date +%s)
    for ZONE in "${ZONES[@]}"; do
        perl -0777 -pi -e "s/^(\\S+\\s+IN\\s+SOA\\s+\\S+\\s+\\S+\\s+\\(\\s+)(\\d+)\\b/\${1}$TS/ms" /etc/bind/db.$ZONE
    done

    echo "restarting ..."
    service bind9 restart
    { ! $FREEZE; } || freeze_or_thaw thaw

    #  Purge nscd's cache
    nscd -i hosts
}

freeze_or_thaw()
{
    miniade_info "${1%e}ing ..."
    for ZONE in "${ZONES[@]}"; do
        if [[ $ZONE =~ ^[0-9] ]]; then
            ZONE_SUFFIX=.in-addr.arpa
        else 
            ZONE_SUFFIX=
        fi
        rndc $1 $ZONE$ZONE_SUFFIX
    done
}

init_zone()
{
    local ZONE ZONE_SUFFIX

    ZONE=$1
    if [[ $ZONE =~ ^[0-9] ]]; then
        ZONE_SUFFIX=.in-addr.arpa
    else 
        ZONE_SUFFIX=
    fi

    p() { printf "%-38s IN %-5s %s\\n" "$1" "$2" "$3"; }
    {
        echo "; Define what gets appended to unqualified things on the left. '@' is an alias for this too."
        echo "\$ORIGIN $ZONE$ZONE_SUFFIX."
        echo "; Records may specify a TTL but we define a default."
        echo "\$TTL 1h"
        echo
        p @ SOA "ns.$(dnsdomainname). root.$(dnsdomainname). ( $(date +%s) 1d 2h 4w 1h )"
        p @ NS  "$(hostname -f)."
    } > /etc/bind/db.$ZONE
}

init_named_conf_local()
{
    local ZONE ZONE_SUFFIX

    for ZONE in "${ZONES[@]}"; do
        if [[ $ZONE =~ ^[0-9] ]]; then
            ZONE_SUFFIX=.in-addr.arpa
        else 
            ZONE_SUFFIX=
        fi
        echo -e "zone \"$ZONE$ZONE_SUFFIX\" {"
        echo -e "\\ttype master;"
        echo -e "\\tfile \"/etc/bind/db.$ZONE\";"
        echo -e "};"
        echo
    done > /etc/bind/named.conf.local
}

main "$@"