#!/usr/bin/env bash

#
# nagios-force-check(1) -- Force an immediate check of a nominated host or
# service.
#
#     $ nac <host>[/<service>]
#
#
# Author: Tom Ryder <tom@sanctum.geek.nz>
# Copyright: 2016
#

# Name self
self=nagios-force-check

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

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

# Bail if -a was selected but there are more arguments
if ((check_all_problems)) && (($#)) ; then
    usage >&2
    exit 1

# Bail if -a wasn't selected and there are no arguments
elif ! ((check_all_problems)) && ! (($#)) ; 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=$(date +%s)
cmdfile=${NAGCMD_FILE:-/usr/local/nagios/var/rw/nagios.cmd}

# Specs are either arguments or all unhandled problems
declare -a specs
if ((check_all_problems)) ; then
    while read -r object ; do
        specs=("${specs[@]}" "$object")
    done < <(nagios-problem-list)
else
    specs=("$@")
fi

# Iterate through the specs given and run the force recheck command
for spec in "${specs[@]}" ; do

    # Check the host or service exists
    if ! nagios-exists "$spec" ; then
        printf '%s: Host/service %s does not seem to exist\n' \
            "$self" "$spec" >&2
    fi

    # If a service name is specified after a slash, figure that out
    if [[ $spec == */* ]] ; then
        host=${spec%/*}
        service=${spec##*/}
    else
        host=$spec
        service=
    fi

    # Write command and print message if it fails; succeed silently
    declare -a cmds
    cmds=()
    if [[ $service ]] ; then
        cmds=("${cmds[@]}" "$(printf '[%lu] SCHEDULE_SVC_CHECK;%s;%s;%lu' \
            "$now" "$host" "$service" "$now")")
    else
        cmds=("${cmds[@]}" "$(printf '[%lu] SCHEDULE_HOST_CHECK;%s;%lu' \
            "$now" "$host" "$now")")
        cmds=("${cmds[@]}" "$(printf '[%lu] SCHEDULE_HOST_SVC_CHECKS;%s;%lu' \
            "$now" "$host" "$now")")
    fi

    # Attempt to write commands to file
    for cmd in "${cmds[@]}" ; do
        if ! printf '%s\n' "$cmd" >> "$cmdfile" ; then
            printf '%s: Failed to write command to file\n' "$self" >&2
            exit 1
        fi
    done
done