#include <sys/syslog.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>


#define BUF_SIZE 1024
#define MAX_PARAMS 4
#define TRUE_RESULT 0x01
#define FALSE_RESULT 0x00

int pop3_check(char *user, char *domain, char *userpass ) {


char buffer[2560];
char  *port="pop3", hostname="mars.neolocation.net", *getstr , username[1000] ; // *username
int i, hnp;
i=hnp=0;

/* connecting to host */

           struct addrinfo hints, *res, *res0;
           int error;
           int s;
           const char *cause = NULL;

           memset(&hints, 0, sizeof(hints));
           hints.ai_family = PF_UNSPEC;
           hints.ai_socktype = SOCK_STREAM;
           error = getaddrinfo(hostname, port, &hints, &res0);
           if (error) {
                   errx(1, "%s", gai_strerror(error));
                   /*NOTREACHED*/
           }
           s = -1;
           for (res = res0; res; res = res->ai_next) {
                   s = socket(res->ai_family, res->ai_socktype,
                       res->ai_protocol);
                   if (s < 0) {
                           cause = "socket";
                           continue;
                   }

                   if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
                           cause = "connect";
                           close(s);
                           s = -1;
                           continue;
                   }

                   break;  /* okay we got one */
           }
           if (s < 0) {
                   err(1, "%s", cause);
                   /*NOTREACHED*/
           }
           freeaddrinfo(res0);

/* end connecting to host */
	fd_set fds;
	struct timeval timeout;
	timeout.tv_sec = 50;
	timeout.tv_usec = 0;
	
	memset(buffer, 0, sizeof(buffer));
	FD_ZERO(&fds);
	FD_SET(s, &fds);
	select(FD_SETSIZE, &fds, NULL, NULL, &timeout);
	read(s,buffer,sizeof(buffer)); //read "OK"
	//printf("got response <- %s\n",buffer);

	memset(buffer, 0, sizeof(buffer));
	FD_ZERO(&fds);
	FD_SET(s, &fds);
	select(FD_SETSIZE, NULL, &fds, NULL, &timeout);
	strcpy(buffer,"user ");
	strcpy(buffer+strlen(buffer),user);
	strcpy(buffer+strlen(buffer),"@");
	strcpy(buffer+strlen(buffer),domain);
	strcpy(buffer+strlen(buffer),"\n");
	//printf("say -> %s\n",buffer);
	syslog( LOG_ERR, "%s", buffer);
	write(s,buffer,strlen(buffer));

	memset(buffer, 0, sizeof(buffer));
	FD_ZERO(&fds);
	FD_SET(s, &fds);
	select(FD_SETSIZE, &fds, NULL, NULL, &timeout);
	read(s,buffer,sizeof(buffer)); //read "OK"
	//printf("got response <- %s\n",buffer);
	syslog( LOG_ERR, "%s", buffer);

	memset(buffer, 0, sizeof(buffer));
	FD_ZERO(&fds);
	FD_SET(s, &fds);
	select(FD_SETSIZE, NULL, &fds, NULL, &timeout);
	strcpy(buffer,"pass ");
	strcpy(buffer+strlen(buffer),userpass);
	strcpy(buffer+strlen(buffer),"\n");
	//printf("say -> %s\n",buffer);
	syslog( LOG_ERR, "%s", buffer);
	write(s,buffer,strlen(buffer));

	memset(buffer, 0, sizeof(buffer));
	FD_ZERO(&fds);
	FD_SET(s, &fds);
	select(FD_SETSIZE, &fds, NULL, NULL, &timeout);
	read(s,buffer,sizeof(buffer)); //read "OK"
	//printf("got response <- %s\n",buffer);
	syslog( LOG_ERR, "%s", buffer);

	if ( strstr(buffer,"+OK")!=NULL ) {
		return 1; //ok
	} else {
		return 0; //fail
	}
}



int main() {
	
	char buf[BUF_SIZE + 1];  // Allow for string termination
	char c;
	char* param[MAX_PARAMS];
	param[0] = &buf[0]; // this won't change...
	
	short len; 
	int i,j;
	
	int result;	
	
	openlog( "ejabberd", LOG_NDELAY, LOG_AUTH );
	syslog( LOG_INFO, "Starting ejabberd check_pop3" );

	while( 1 ) {		
		// read first two bytes from stdin
		// convert bytes to integer len
		i=0;
		while( i<2 ) {
			c = getchar();
			if( c == EOF ) return 0;
			buf[i++] = c;
		}
		len = buf[0]*256 + buf[1];
		
		if( len == 0 ) {
			syslog( LOG_WARNING, "Packet length is zero" );
			// try again 
			continue;
		} else if( len < 0 ) {
			syslog( LOG_ERR, "Negative packet length; exiting" );
			return 1;
		} else if( len > BUF_SIZE ) {
			syslog( LOG_ERR, "Packet length of %d larger than buffer of size %d", len, BUF_SIZE );
			return 1;
		}

		//syslog( LOG_DEBUG, "packet length %d", len );
		
		// read packet of len bytes from stdin to buffer
		// note: packet is on the form [auth|setpass|isuser]:<user>:<domain>:<password>
		// example: 36auth:christoffer:jabberwocky.se:test
		i=0; j=0; 
		while( i<len & j<MAX_PARAMS ) {
			c = getchar();
			if( c == EOF ) return 0;
			
			// split packet on ':'
			if( c == ':' ) {
				// terminate string
				buf[i] = '\0';
				// store index of next string
				// NB if i==BUF_SIZE-1 this will point to the last positon in the array
				// since the length of the array == BUF_SIZE+1 
				param[++j]=&buf[i]+1;
			} else {
				// store character	
				buf[i]=c;
			}
			i++;
		}
		// terminate the last parameter
		buf[i] = '\0';
		// syslog( LOG_INFO, "op: %s, user: %s, domain: %s, pass: %s", \
				param[0], param[1], param[2], param[3] );

		if( strcmp( param[0], "auth" )==0 ) {
			if( j!=3 ) {
				syslog( LOG_ERR, "Expected exactly four parameters, found %d", j+1 );
				return 1;
			}
			result = pop3_check(param[1],param[2], param[3]);
			syslog( LOG_DEBUG, \
				"Authentication for user '%s@%s' %s", \
				param[1], \
				param[2], \
				result ? "was successfull" : "failed" );
		} else if( strcmp( param[0], "setpass" )==0 ) { 
			// TODO: Test setpass operation
			if( j!=3 ) {
				syslog( LOG_ERR, "Expected exactly four parameters, found %d", j+1 );
				return 1;
			}
			result = NULL;
			syslog( LOG_INFO, "The password for user '%s@%si' %s changed", \
				param[1], param[2], result == 0 ? "was" : "could not be" );
		} else if( strcmp( param[0], "isuser" )==0 ) {
			// TODO: Test isuser operation
			// FIXME: Find out if the password is sent or not, i.e. if we get
			// 		  three or four parameters.
			if( j<2 ) {
				syslog( LOG_ERR, "Expected at least two parameters, found %d", j+1 );
				return 1;
			}
			// The theory is: if we get a passwd struct back, the user exists...
			result = NULL;
		} else {
			// if we don't know what to do, the result is a failure
			result = 0;  
			// log warning
			syslog( LOG_ERR, "Unknown operation '%s'", param[0] );
		}			
		// write back the result length (2 bytes)		
		//fputs( "\x00\x02", stdout );
		putchar( 0x00 );
		putchar( 0x02 );
		// write back the result
		putchar( 0x00 );
		putchar( result ? TRUE_RESULT : FALSE_RESULT );
		fflush( stdout );
		// syslog( LOG_DEBUG, "Returned result" );
	}	
	return 0;
}