/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.  If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

#include <stdio.h>

#include <isc/app.h>
#include <isc/commandline.h>
#include <isc/log.h>
#include <isc/print.h>
#include <isc/string.h>

#include <named/globals.h>
#include <named/main.h>
#include <named/ntservice.h>
#include <named/server.h>

/* Handle to SCM for updating service status */
static SERVICE_STATUS_HANDLE hServiceStatus = 0;
static BOOL foreground = FALSE;
static char ConsoleTitle[128];

/*
 * Forward declarations
 */
static int
bindmain_service_wrapper(int argc, char *argv[]);
void
ServiceControl(DWORD dwCtrlCode);
int
bindmain(int, char *[]); /* From main.c */

/*
 * Initialize the ISC library running as a Windows Service before calling
 * bindmain()
 */
static int
bindmain_service_wrapper(int argc, char *argv[]) {
	return (isc_lib_ntservice(bindmain, argc, argv));
}

/*
 * Initialize the Service by registering it.
 */
void
ntservice_init(void) {
	if (!foreground) {
		/* Register handler with the SCM */
		hServiceStatus = RegisterServiceCtrlHandler(
			BIND_SERVICE_NAME, (LPHANDLER_FUNCTION)ServiceControl);
		if (!hServiceStatus) {
			named_main_earlyfatal("could not register service "
					      "control handler");
		}
		UpdateSCM(SERVICE_RUNNING);
	} else {
		strlcpy(ConsoleTitle, "BIND Version ", sizeof(ConsoleTitle));
		strlcat(ConsoleTitle, VERSION, sizeof(ConsoleTitle));
		SetConsoleTitle(ConsoleTitle);
	}
}

void
ntservice_shutdown(void) {
	UpdateSCM(SERVICE_STOPPED);
}

/*
 * Routine to check if this is a service or a foreground program
 */
BOOL
ntservice_isservice(void) {
	return (!foreground);
}

/*
 * ServiceControl(): Handles requests from the SCM and passes them on
 * to named.
 */
void
ServiceControl(DWORD dwCtrlCode) {
	/* Handle the requested control code */
	switch (dwCtrlCode) {
	case SERVICE_CONTROL_INTERROGATE:
		UpdateSCM(0);
		break;

	case SERVICE_CONTROL_SHUTDOWN:
	case SERVICE_CONTROL_STOP:
		named_server_flushonshutdown(named_g_server, true);
		isc_app_shutdown();
		UpdateSCM(SERVICE_STOP_PENDING);
		break;
	default:
		break;
	}
}

/*
 * Tell the Service Control Manager the state of the service.
 */
void
UpdateSCM(DWORD state) {
	SERVICE_STATUS ss;
	static DWORD dwState = SERVICE_STOPPED;

	if (hServiceStatus) {
		if (state) {
			dwState = state;
		}

		memset(&ss, 0, sizeof(SERVICE_STATUS));
		ss.dwServiceType |= SERVICE_WIN32_OWN_PROCESS;
		ss.dwCurrentState = dwState;
		ss.dwControlsAccepted = SERVICE_ACCEPT_STOP |
					SERVICE_ACCEPT_SHUTDOWN;
		ss.dwCheckPoint = 0;
		ss.dwServiceSpecificExitCode = 0;
		ss.dwWin32ExitCode = NO_ERROR;
		ss.dwWaitHint = dwState == SERVICE_STOP_PENDING ? 10000 : 1000;

		if (!SetServiceStatus(hServiceStatus, &ss)) {
			ss.dwCurrentState = SERVICE_STOPPED;
			SetServiceStatus(hServiceStatus, &ss);
		}
	}
}

/* unhook main */

#undef main

/*
 * This is the entry point for the executable
 * We can now call bindmain() explicitly or via StartServiceCtrlDispatcher()
 * as we need to.
 */
int
main(int argc, char *argv[]) {
	int rc, ch;

	/* Command line users should put -f in the options. */
	isc_commandline_errprint = false;
	while ((ch = isc_commandline_parse(argc, argv, NAMED_MAIN_ARGS)) != -1)
	{
		switch (ch) {
		case 'f':
		case 'g':
		case 'v':
		case 'V':
			foreground = TRUE;
			break;
		default:
			break;
		}
	}
	isc_commandline_reset = true;

	if (foreground) {
		/* run in console window */
		exit(bindmain(argc, argv));
	} else {
		/* Start up as service */
		char *SERVICE_NAME = BIND_SERVICE_NAME;

		SERVICE_TABLE_ENTRY dispatchTable[] = {
			{ TEXT(SERVICE_NAME),
			  (LPSERVICE_MAIN_FUNCTION)bindmain_service_wrapper },
			{ NULL, NULL }
		};

		rc = StartServiceCtrlDispatcher(dispatchTable);
		if (!rc) {
			fprintf(stderr, "Use -f to run from the command "
					"line.\n");
			/* will be 1063 when launched as a console app */
			exit(GetLastError());
		}
	}
	exit(0);
}