#!/usr/bin/perl

use v5.14;
use strict;
use warnings;

use DBI;
use Win32::Service;

##
# Hostname of server where this script is being run.
#
my $hostname = `hostname`;
chomp $hostname;

##
# Reference to anonymous array returned by GetStatus.
#
my $w32ServiceStatus = {};

##
# Win32 API service status constants.
#
use constant {
	SERVICE_STOPPED            => hex('0x00000001'),
	SERVICE_START_PENDING      => hex('0x00000002'),
	SERVICE_STOP_PENDING       => hex('0x00000003'),
	SERVICE_RUNNING            => hex('0x00000004'),
	SERVICE_CONTINUE_PENDING   => hex('0x00000005'),
	SERVICE_PAUSE_PENDING      => hex('0x00000006'),
	SERVICE_PAUSED             => hex('0x00000007'),
};

##
# Additional script constants.
#
use constant {
	SLEEP_INTERVAL             => 15,              # Time to sleep between tries (sec.).
	MAX_WAIT_TIME              => 15,              # Max time to wait for service to stop (min.).
	SERVICE_NAME               => 'MY_SERVICE',    # Service name.
};

#######################################################################
# Get the current status of the service and stop it, if running.
#
Win32::Service::GetStatus('',SERVICE_NAME,$w32ServiceStatus);
if ($w32ServiceStatus->{CurrentState} == SERVICE_RUNNING) {
    ##
    # Process ID.
    #
    my $pid = -999;
    
    ##
    # WMI database handle object.
    #
    my $dbh = DBI->connect('dbi:WMI:');
    
    ##
    # WMI statement handle object.
    #
    my $sth = $dbh->prepare(
            sprintf ("SELECT * FROM Win32_Service WHERE Name = '%s'",
                    SERVICE_NAME));
    $sth->execute();
    if (my $row = $sth->fetchrow()) {
        $pid = $row->ProcessID;
    }

    printf("Attempting to stop %s on $hostname...\n",SERVICE_NAME);
    
    ###################################################################
    # Stop the service.
    #
    Win32::Service::StopService('',SERVICE_NAME)
           or die sprintf("Unable to stop %s on %s: %s\n",
                    SERVICE_NAME,$hostname,$!);
    printf("%s on %s stopping.\n",SERVICE_NAME,$hostname);
    
    ###################################################################
    # Continue to wait until the process is fully stopped.
    #
    my $stopCount = 0;
    while ($pid > 0 && $stopCount < (60 / SLEEP_INTERVAL * MAX_WAIT_TIME)) {
    	sleep SLEEP_INTERVAL;
    	$sth->execute();
    	if (my $row = $sth->fetchrow()) {
    		$pid = $row->ProcessID;
    	}
        $stopCount++;
    }
    
    ###################################################################
    # If the time taken to stop exceeds the maximum wait time, then
    # error out.
    #
    if ($stopCount < (60 / SLEEP_INTERVAL * MAX_WAIT_TIME)) {
    	printf("%s stopped on %s.\n",SERVICE_NAME,$hostname);
    } else {
        die sprintf("Unable to stop %s on %s: %s\n",
                SERVICE_NAME,$hostname,$!);
    }
}

#######################################################################
# Service is not running.
#
else {
	printf("%s is not currently running on %s.\n",SERVICE_NAME,$hostname);
}

#######################################################################
# ...do whatever we're going to do before restarting the service...
#

#######################################################################
# Restart the service, if it was running to start with.
#
if ($w32ServiceStatus->{CurrentState} == SERVICE_RUNNING) {
	printf("Attempting to start %s on %s.\n",SERVICE_NAME,$hostname);
    Win32::Service::StartService('',SERVICE_NAME)
            or die sprintf("Unable to start %s on %s.\n",SERVICE_NAME,$hostname);
    printf("%s on %s started.\n",SERVICE_NAME,$hostname);
}