#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <syslog.h>
#include <unistd.h>
#include <misc.h>
#include "process.h"
#include "monitortasks.m"

static void usage()
{
	fprintf (stderr,MSG_U(I_USAGE
		,"taskmon %s\n"
		 "\n"
		 "taskmon [ --cycle seconds ] [ --config config_file ]\n"
		 "        [ --signum signal ] [ --mail email ]\n"
		 "\n"
		 "signum: signal number used to kill the processes (default SIGTERM)\n"
		 "email: Process termination acknoledge will be sent there\n"
		 "       They are registered in syslog as well\n"
		 "seconds: wakes up every \"seconds\" time\n"
		 "\n"
		 "config_file: path of the config file\n"
		 "     It contains lines in the following format:\n"
		 "      process_name percent\n"
		 "		...\n"
		 "percent represent the maximum cpu time fraction of a cycle.\n"
		 "Any offending process will be killed.\n")
		,PACKAGE_REV);
	exit (-1);
}

class PMON: public ARRAY_OBJ{
public:
	SSTRING name;
	int pid;
	long accum;		// Accumulated time since process start
	bool mark;		// To clean up old process
	int signaled;
	/*~PROTOBEG~ PMON */
public:
	PMON (const char *_name, int _pid);
	/*~PROTOEND~ PMON */
};

PUBLIC PMON::PMON(const char *_name, int _pid)
{
	pid = _pid;
	name.setfrom (_name);
	mark = false;
	accum = 0;
	signaled = 0;
}

class PMONS: public ARRAY{
	/*~PROTOBEG~ PMONS */
public:
	PMON *getitem (int no)const;
	PMON *locatepid (int pid)const;
	/*~PROTOEND~ PMONS */
};

PUBLIC PMON *PMONS::getitem(int no) const
{
	return (PMON*)ARRAY::getitem(no);
}

PUBLIC PMON *PMONS::locatepid(int pid) const
{
	PMON *ret = NULL;
	for (int i=0; i<getnb(); i++){
		PMON *m = getitem (i);
		if (m->pid == pid){
			ret = m;
			break;
		}
	}
	return ret;
}

class CONFPROC: public ARRAY_OBJ{
public:
	SSTRING name;
	int maxaccum;		// Maximum allowed process time in one
						// pass
	/*~PROTOBEG~ CONFPROC */
public:
	CONFPROC (const char *_name, int _maxaccum);
	/*~PROTOEND~ CONFPROC */
};

PUBLIC CONFPROC::CONFPROC(const char *_name, int _maxaccum)
{
	name.setfrom (_name);
	maxaccum = _maxaccum;
}

class CONFPROCS: public ARRAY{
	/*~PROTOBEG~ CONFPROCS */
public:
	CONFPROCS (const char *config, int cycle);
	CONFPROC *getitem (int no)const;
	CONFPROC *lookup (const char *name)const;
	/*~PROTOEND~ CONFPROCS */
};

PUBLIC CONFPROC *CONFPROCS::getitem (int no) const
{
	return (CONFPROC*)ARRAY::getitem(no);
}

PUBLIC CONFPROC *CONFPROCS::lookup(const char *name) const
{
	CONFPROC *ret = NULL;
	int n = getnb();
	for (int i=0; i<n; i++){
		CONFPROC *c = getitem(i);
		if (c->name.cmp(name)==0){
			ret = c;
			break;
		}
	}
	return ret;
}

PUBLIC CONFPROCS::CONFPROCS(const char *config, int cycle)
{
	CONFIG_FILE ff (config,help_nil,CONFIGF_NONE);
	FILE_CFG *fin = ff.fopen ("r");
	if (fin != NULL){
		char buf[1000];
		while (fgets_strip (buf,sizeof(buf)-1,fin,NULL)!=NULL){
			if (buf[0] != '\0'){
				char name[1000];
				char *pt = str_copyword (name,buf,sizeof(name)-1);
				pt = str_skip(pt);
				int percent = atoi(pt);
				if (percent <= 0) percent = 75;
				percent = percent * cycle / 100;
				add (new CONFPROC (name,percent));
			}
		}
		fclose (fin);
	}
}


int main (int argc, char *argv[])
{
	linuxconf_loadlibmsg("linuxconf");
	linuxconf_loadmsg ("monitortasks",PACKAGE_REV);
	const char *config = "/etc/monitortasks.conf";
	int cycle = 60;
	int signum = SIGTERM;
	const char *mail = "root";
	for (int i=1; i<argc; i++){
		const char *arg = argv[i];
		const char *arg2 = argv[i+1];
		if (strcmp(arg,"--config")==0){
			i++;
			if (arg2 != NULL){
				config = arg2;
			}else{
				usage();
			}
		}else if (strcmp(arg,"--cycle")==0){
			i++;
			if (arg2 != NULL){
				cycle = atoi(arg2);
			}else{
				usage();
			}
		}else if (strcmp(arg,"--signum")==0){
			i++;
			if (arg2 != NULL){
				signum = atoi(arg2);
			}else{
				usage();
			}
		}else if (strcmp(arg,"--mail")==0){
			i++;
			if (arg2 != NULL){
				mail = arg2;
			}else{
				usage();
			}
		}else if (strcmp(arg,"--help")==0){
			usage();
		}else{
			usage();
		}
	}
	PMONS pmons;
	CONFPROCS confs (config,cycle);
	if (confs.getnb()==0){
		fprintf (stderr,MSG_U(E_NOCONF,"No process configured in %s\n")
			,config);
		exit (-1);
	}
	while (1){
		int n = pmons.getnb();
		for (int i=0; i<n; i++){
			pmons.getitem(i)->mark = false;
		}
		PROC *pt = process_getfirst();
		while (pt != NULL){
			// const char *ppath = pt->getpath();
			const char *pname = pt->getname();
			CONFPROC *cp = confs.lookup(pname);
			if (cp != NULL){
				int pid = pt->getpid();
				PMON *m = pmons.locatepid(pid);
				long accum = pt->getcputime();
				if (m == NULL){
					m = new PMON(pname,pid);
					pmons.add (m);
				}else{
					int diff = accum - m->accum;
					if (diff >= cp->maxaccum){
						// printf ("pid %d accum %d >= %d\n",pid,diff,cp->maxaccum);
						pt->kill(signum);
						m->signaled++;
						if (m->signaled == 1){	 	
							char msg[1000];
							snprintf (msg,sizeof(msg)-1
								,MSG_U(I_MAIL,"Process %s have been terminated")
								,pname);
							char cmd[1000];
							snprintf (cmd,sizeof(cmd)-1
								,"echo %s | mail -s \"taskmon: %s\" %s"
								,msg,pname,mail);
							system (cmd);
						}
						syslog (LOG_ERR,MSG_U(E_KILLING
							,"Terminating process %s(%d)"),pname,pid);
					}
				}
				m->accum = accum;
				m->mark = true;
			}
			pt = pt->getnext();
		}
		n = pmons.getnb();
		for (int i=0; i<n; i++){
			PMON *m = pmons.getitem(i);
			if (!m->mark){
				pmons.remove_del (i);
				i--;
				n--;
			}
		}
		#if 0
			for (int i=0; i<pmons.getnb(); i++){
				PMON *m = pmons.getitem(i);
				printf ("pmon name=%s pid=%d %ld seconds\n"
					,m->name.get(),m->pid,m->accum);
			}
		#endif
		sleep (cycle);
	}
	return 0;
}