#!/usr/bin/env bash

#
# nagios-clear(1) -- Shortcut to removing all active downtime and
# acknowledgements from a host.
#
self=nagios-clear

# Usage printing function
usage() {
    printf 'USAGE: %s [<host[/service][,host[/service],...>|-] [comment]\n' "$self"
}

# Process options (just help at the moment)
OPTIND=1
while getopts 'h' opt ; do
    case "$opt" in
        h)
            usage
            exit 0
            ;;
        '?')
            usage >&2
            exit 1
            ;;
    esac
done
shift "$((OPTIND-1))"

# Bail if too few arguments left; we need at least an object name; the comma is
# optional
if ! (($#)) ; then
    usage >&2
    exit 1
fi

# Define relatively fixed/guaranteed fields for Nagios command; note that the
# comment has a default of 'no comment given'
now=$(date +%s)
author=${SUDO_USER:-"$USER"}
spec=$1
comment=${2:-'no comment given'}
cmdfile=${NAGCMD_FILE:-/usr/local/nagios/var/rw/nagios.cmd}

# Define the path to the Livestatus socket
socket=${MK_LIVESTATUS_SOCKET:-/usr/local/nagios/var/rw/live}

# How to get the objects depends on the spec (the first argument)
declare -a objects
case $spec in

    # If the spec is just "-", we just read unique objects from stdin
    -)
        while read -r object ; do
            [[ $object ]] || continue
            objects[${#objects[@]}]=$object
        done < <(sort -u)
        ;;

    # If the spec is anything else, we break it up with commas and read the
    # objects that way
    *)
        IFS=, read -a objects -r < <(printf '%s\n' "$spec")
        ;;
esac

# There must be at least one object
if ! ((${#objects[@]})) ; then
    printf '%s: At least one host/service must be given\n' \
        "$self" >&2
    exit 1
fi

# All the hosts or services must exist, just to be strict
for object in "${objects[@]}" ; do
    nagios-exists "$object" && continue
    printf '%s: Host/service %s does not seem to exist\n' \
        "$self" "$object" >&2
    exit 1
done

# Write commands to remove acknowledgements for each of the objects
for object in "${objects[@]}" ; do
    case $object in
        */*)
            host=${object%/*}
            service=${object##*/}
            printf '[%lu] REMOVE_SVC_ACKNOWLEDGEMENT;%s;%s\n' \
                "$now" "$host" "$service"
            unixcat "$socket" <<EOF |
GET downtimes
Columns: id
Filter: host_name = $host
Filter: service_description = $service
EOF
            while read -r id ; do
                printf '[%lu] DEL_SVC_DOWNTIME;%u\n' \
                    "$now" "$id"
            done
            ;;
        *)
            host=$object
            printf '[%lu] REMOVE_HOST_ACKNOWLEDGEMENT;%s\n' \
                "$now" "$host"
            unixcat "$socket" <<EOF |
GET downtimes
Columns: id
Filter: host_name = $host
Filter: service_description = ''
EOF
            while read -r id ; do
                printf '[%lu] DEL_HOST_DOWNTIME;%u\n' \
                    "$now" "$id"
            done
            ;;
    esac
done > "$cmdfile"