#include <iostream>
#include <sstream>
#include <signal.h>
#include <fcntl.h>
#include <stdlib.h>
#include <cstring>

#include <sys/types.h>
#include <pwd.h>
#include <grp.h>


#include "ConfigFile.h"
#include "daemon.h"
#include "common.h"
#include "Logger.h"



using namespace std;


void signal_handler(int sig)
{
	switch (sig)
	{
	case SIGHUP:
		Logger::logMessage("hangup signal catched");
		break;

	case SIGTERM:
		Logger::logMessage("terminate signal catched...exiting");
		Common::instance()->mainContinue = false;
		break;
	default:
		std::stringstream ss;
		ss << "Received unknown signal: " << sig;
		Logger::logMessage(ss.str());
		break;
	}
}

void lookup_uid_values()
{
	Common* cmn = Common::instance();

	std::string userstr = cmn->GetConfigfile()->GetValue("smsdaemon","user");
	std::string groupstr = cmn->GetConfigfile()->GetValue("smsdaemon","group");

	passwd* pass = getpwnam(userstr.c_str());
	if (pass != 0)
	{
		cmn->uid = pass->pw_uid;
	}
	else
	{
		Logger::logMessage( string("could not lookup userid: ") + userstr );
		exit(1);
	}


	group* grp = getgrnam(groupstr.c_str() );
	if (grp != 0)
	{
		cmn->gid = grp->gr_gid;
	}
	else
	{
		Logger::logMessage( string("could not lookup groupid: ") + groupstr );
		exit(1);
	}
}


void daemonCleanup()
{
	unlink( Common::instance()->pidfile.c_str() );
}

void daemonize()
{
	int i, lfp;
	char str[10];
	Common* cmn = Common::instance();

	if (getuid() != 0)
	{
		cout << "Please start this daemon as root\n" << endl;
		daemon_shutdown(0);
	}


	if (getppid() == 1) /* already a daemon */
		return;

	i=fork();

	if (i<0) /* fork error */
		daemon_shutdown(FORK_ERROR);
	if (i>0) /* parent exits */
		daemon_shutdown(0);
	/* child daemon continues */

	setsid(); /* obtain a new process group */

	for (i=getdtablesize(); i>=0; --i)
		close(i); /*close all descriptors*/

	i=open("/dev/null", O_RDWR); /* handle std. io */
	dup(i);
	dup(i);

	umask(027); /* set newly created file permissions */

	chdir("/tmp"); /* change running directory*/

	/*attempt to create lockfile and put a file-lock on it*/
	lfp=open(cmn->pidfile.c_str(), O_RDWR|O_CREAT, 0640);
	if (lfp<0) /* can not open */
		daemon_shutdown(CANT_OPEN_LOCK);
	if (lockf(lfp,F_TLOCK,0) < 0) /* can not lock */
		daemon_shutdown(ALREADY_LOCKED);

	/* first instance continues */
	sprintf(str, "%d\n", getpid() ); /* record pid to lockfile */
	write(lfp, str, strlen(str) );
	//signal(SIGCHLD, SIG_IGN); /* ignore child */
	signal(SIGTSTP, SIG_IGN); /* ignore tty signals */
	signal(SIGTTOU, SIG_IGN);
	signal(SIGTTIN, SIG_IGN);
	signal(SIGHUP, signal_handler); /* catch hangup signal */
	signal(SIGTERM, signal_handler); /* catch kill signal */
	signal(SIGINT, signal_handler); /* keyboard interrupt */
	signal(SIGQUIT, signal_handler); /* QUIT */

	/*this program is now a daemon*/
	setegid( cmn->gid );
	seteuid( cmn->uid );
}