#!/bin/bash
#  $HeadURL$ $LastChangedRevision$

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

#  Configurable stuff

#  Other globals

main()
{
    local MY_ARGS
    #  Defaults for options
    OPT_TIMEOUT=5

    #  Process options
    special_opts_handler()
    {
        case $1 in
            --timeout=*) OPT_TIMEOUT=${1#*=} ;;
            *)           return 1 ;;
        esac
    }
    miniade_process_options --help-handler=help --special-opts-handler=special_opts_handler MY_ARGS "$@" && set -- "${MY_ARGS[@]}"

    #  Process arguments
    [ $# -ge 1 ] || miniade_bad_usage

    #  Guts
    OK=true
    for CMDLINE_ARG in "$@"; do
        case $CMDLINE_ARG in
            gateway)  check_hostnames $(ip -4 -o route | sed -nr 's/default via (.*) dev .*/\1/p') || OK=false ;;
            internet) check_hostnames 8.8.8.8 || OK=false ;;
            repos)    check_urls $(sed -nr 's/^deb ([^ ]+?:\/\/[^ /]+).*/\1/p' /etc/apt/sources.list /etc/apt/sources.list.d/* 2>/dev/null | sort -u | paste -d' ' -s) || OK=false ;;
            *)        check_hostnames_or_urls $CMDLINE_ARG || OK=false ;;
        esac
    done

    $OK || miniade_error "$CMDLINE_ARG: not reachable or resolution problem (depending how caller handles this, it may be okay)"
}

help()
{
    local PROGNAME

    miniade_get_progname PROGNAME
    echo "Usage: $PROGNAME [ <standard-options> ] [ --timeout=<secs> ] { gateway | repos | internet | <host> } ...>"
    exit 0
}

check_hostnames()
{
    local TARGET_HOSTNAME TARGET_HOSTNAMES STOP_TIMESTAMP NOW_TIMESTAMP

    TARGET_HOSTNAMES=( "$@" )

    for TARGET_HOSTNAME in "${TARGET_HOSTNAMES[@]}"; do
        miniade_debug 10 "check_hostnames: $TARGET_HOSTNAME: checking ..."
        STOP_TIMESTAMP=$(($(date +%s) + $OPT_TIMEOUT))
        while :; do
            NOW_TIMESTAMP=$(date +%s)
            miniade_debug 10 "check_hostnames: NOW_TIMESTAMP=$NOW_TIMESTAMP, STOP_TIMESTAMP=$STOP_TIMESTAMP"
            #  depending which ping we're using, subsecond waits may not be possible.
            if ping -c 1 -w 1 $TARGET_HOSTNAME > /dev/null 2>/dev/null; then
                break
            fi
            if (($NOW_TIMESTAMP >= $STOP_TIMESTAMP)); then
                return 1
            fi
        done
    done
}

check_urls()
{
    local TARGET_URL TARGET_URLS TARGET_PROTOCOL TARGET_HOSTNAME

    TARGET_URLS=( "$@" )

    [ -w / ] || miniade_error "testing URLs requires root! (because 'nmap -sS' requires root)"

    for TARGET_URL in "${TARGET_URLS[@]}"; do
        miniade_debug 10 "check_urls: $TARGET_URL: checking ..."
        [[ $TARGET_URL =~ (http|https|ftp)://([^/]+)(/.*)? ]] || miniade_internal "check_urls: $TARGET_URL: invalid/unsupported URL"
        TARGET_PROTOCOL=${BASH_REMATCH[1]}
        TARGET_HOSTNAME=${BASH_REMATCH[2]}
        TARGET_PATH=${BASH_REMATCH[3]}
        miniade_debug 10 "check_urls: TARGET_PROTOCOL=$TARGET_PROTOCOL, TARGET_HOSTNAME=$TARGET_HOSTNAME, TARGET_PATH=$TARGET_PATH"
        NMAP_CMDLINE="nmap -sS -p $TARGET_PROTOCOL $TARGET_HOSTNAME"
        miniade_debug 10 "check_urls: calling [$NMAP_CMDLINE] ..."
        NMAP_OUTPUT=$(eval "$NMAP_CMDLINE" 2>&1) || true
        if ! [[ $NMAP_OUTPUT =~ open ]]; then
            miniade_warning "nmap failed (command was '$NMAP_CMDLINE', output was '$NMAP_OUTPUT')" 
            return 1
        fi
    done
}

check_hostnames_or_urls()
{
    local TARGET_THINGS TARGET_THING
   
    TARGET_THINGS=( "$@" )

    for TARGET_THING in "${TARGET_THINGS[@]}"; do
        miniade_debug 10 "check_hostnames_or_urls: TARGET_THING=$TARGET_THING"
        if [[ $TARGET_THING =~ :// ]]; then
            check_urls $TARGET_THING || return 1
        else
            check_hostnames $TARGET_THING || return 1
        fi
    done
}

main "$@"