/*
	This file is part of Bolixo.

	Bolixo is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	Bolixo is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with Bolixo.  If not, see <https://www.gnu.org/licenses/>.
*/
/*
	This is a small server that acts as an email server. It support the SMTP protocol minimally
	and log everthing it receives in a file.

	This is used for testing and preproduction where we do not want test email to go out, yet we want
	to test the complete sequence (even exim configuration).
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tlmplib.h>
#include <tlmpnet.h>
#include <string>
#include <helper.h>

using namespace std;


struct HANDLE_INFO: public ARRAY_OBJ{
	enum class STATE { init, helo, from, to, data, quit} state = STATE::init;
	string from;
	string to;
	string data;
};

static const char *ivld500 = "500 unrecognized command\r\n";

<mod>
int main (int argc, char *argv[])
{
	glocal int ret = -1;
	glocal const char *port = "2025";
	glocal const char *logfile = "/var/log/email-log.log";
	glocal const char *user = "bolixo";
	glocal bool daemon = false;
	glocal const char *pidfile = "/var/run/email-log.pid";
	glocal.ret = <call tlmpprogram>(argc,argv);
	<f init>
		setproginfo ("email-log",VERSION,"Listen on port 25 and log everything received");
		setarg ('l',"logfile","Log file path",glocal.logfile,false);
		setarg ('p',"port","TCP port",glocal.port,false);
		setarg (' ',"user","Run the program as this user",glocal.user,false);
		setarg (' ',"daemon","Run in background",glocal.daemon,false);
		setarg (' ',"pidfile","File holding the PID of the process",glocal.pidfile,false);
	</f>
	<f main_noarg>
		int ret = -1;
		glocal FILE *flog = fopen (glocal.logfile,"a");
		if (glocal.flog == NULL){
			tlmp_error ("Can't open log file %s (%s)\n",glocal.logfile,strerror(errno));
			exit(-1);
		}
		<obj TCPSERVER o>(glocal.port,10);
		<f newclient>
			info.data = new HANDLE_INFO;
			send ("220 email-log SMTP\r\n");
		</f>
		<f endclient>
			HANDLE_INFO *c = (HANDLE_INFO*)info.data;
			fprintf (glocal.flog,"-------\nfrom: %s\nto: %s\ndata\n%s\n"
				,c->from.c_str(),c->to.c_str(),c->data.c_str());
			fflush (glocal.flog);
		</f>
		<f receive>
			HANDLE_INFO *c = (HANDLE_INFO*)info.data;
			if (strcmp(line,"quit")==0){
				endclient = true;
			}else{
				const char *pt;
				switch(c->state){
				case HANDLE_INFO::STATE::init:
					if (is_start_any_ofnc(line,pt,"helo","ehlo")){
						sendf ("250 helo %s email-log\r\n",pt);
						c->state = HANDLE_INFO::STATE::helo;
					}else{
						send (ivld500);
					}
					break;
				case HANDLE_INFO::STATE::helo:
					if (is_start_any_ofnc(line,pt,"mail from:")){
						send ("250 OK\r\n");
						c->state = HANDLE_INFO::STATE::from;
						c->from = pt;
					}else{
						send (ivld500);
					}
					break;
				case HANDLE_INFO::STATE::from:
					if (is_start_any_ofnc(line,pt,"rcpt to:")){
						send ("250 Accepted\r\n");
						c->state = HANDLE_INFO::STATE::to;
						c->to = pt;
					}else{
						send (ivld500);
					}
					break;
				case HANDLE_INFO::STATE::to:
					if (strcasecmp(line,"data")==0){
						send ("354 Enter message, ending with \".\" on a line by itself\r\n");
						c->state = HANDLE_INFO::STATE::data;
					}else{
						send (ivld500);
					}
					break;
				case HANDLE_INFO::STATE::data:
					if (strcmp(line,".")==0){
						send ("250 OK id=1hF33o-0002JA-4g\r\n");
						c->state = HANDLE_INFO::STATE::quit;
					}else{
						c->data += line;
						c->data += "\r\n";
					}
					break;
				case HANDLE_INFO::STATE::quit:
					if (strcasecmp(line,"quit")==0){
						send ("221 closing connection\r\n");
						endclient = true;
					}else{
						send (ivld500);
					}
					break;
				}
			}
		</f>
		</obj>
		if (o.is_ok()){
			if (glocal.daemon){
				daemon_init(glocal.pidfile,glocal.user);
			}
			o.loop();
		}
		return ret;
	</f>
	</call>
	return glocal.ret;
}
</mod>