/* vim: set sw=4 ts=4 si et: */

#include <pthread.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _GYR_PRELOAD
void __attribute__ ((constructor)) detector_init(void);
#endif

typedef struct {
	char * hostname;
	int port;
} detector_serv_t;

void * detector_thread_fun(void * paramvoid){
	detector_serv_t * param = paramvoid;

	printf("Thread launched\n");
	// se connecter
	int socket_desc = socket(AF_INET, SOCK_STREAM, 0);
	if (socket_desc < 0){
		perror("Creation de la socket impossible");
		fprintf(stderr,"BOUM at %s:%d\n",__FILE__,__LINE__);
		exit(-1);
	}
	
	printf("Lookup for %s...\n", param->hostname);
	struct hostent * server = gethostbyname(param->hostname);
	if (server == NULL){
		fprintf(stderr, "Error, no such host\n");
		exit(-1);
	}

	printf("Host found\n");
	
	struct sockaddr_in * myaddr = 
		(struct sockaddr_in *) malloc (sizeof(struct sockaddr_in));
	bzero(myaddr, sizeof(struct sockaddr_in));
	myaddr->sin_family = AF_INET;
	myaddr->sin_port = htons(param->port);

	memcpy (&(myaddr->sin_addr.s_addr), server->h_addr, sizeof(u_long)); 
	// myaddr->sin_addr.s_addr = server->h_addr[0];

	/*
	   bcopy((char *)(server->h_addr),
	   (char *)(myaddr->sin_addr.s_addr),
	   server->h_length);
	 */

	if (connect(socket_desc, 
				(struct sockaddr *)myaddr, 
				sizeof(struct sockaddr_in)) < 0){
		perror("Attachement de la socket impossible");
		fprintf(stderr,"No connect at %s:%d\n",__FILE__,__LINE__);	
		exit(-1);
	}
	printf("Thread connected\n");

	char hostname[50];
	gethostname(hostname, 50);
	char ident[100];
	sprintf(ident, "%d@%s", getpid(), hostname);

	char * message = (char *) malloc (sizeof(char) * 1024);
	memset(message, 0, 1024);
	sprintf(message, "register:%s\n", ident);

	write(socket_desc, message, strlen(message)); 

	// indiquer au serveur qu'il faut qu'il vérifie ce prog
	// identifant pid
	while(1){
		// on attend "status?", on répond "alive!"
		int recv_len;
		memset(message, 0, 1024);
		recv_len = recv (socket_desc, message, 1024, 0);

		if (!strncmp("status?", message, 7)){
			send (socket_desc, "alive!", 6, 0);
		}

	}
	// se déconnecter ?

}

void detector_init(){
	// créer un thread "a part" qui répond au serveur
	// et retourner dans le programme principal
	pthread_t thr_detector;
	pthread_attr_t thr_att;

	pthread_attr_init(&thr_att);

	detector_serv_t * param = (detector_serv_t *)
		malloc (sizeof(detector_serv_t));
	// FIXME: read environment variable
	param->hostname = getenv("DETECTOR_HOSTNAME");
	if (param->hostname == NULL){
		fprintf(stderr,"Undefined envirnoment variable DETECTOR_HOSTNAME\n");
	}

	//FIXME: read env variable
	char * portstr = getenv("DETECTOR_PORT");
	if (portstr == NULL){
		fprintf(stderr,"Undefined envirnoment variable DETECTOR_HOSTNAME\n");
	}
	sscanf(portstr, "%d", &(param->port));
	printf("HOST (%s) PORT (%d)\n", param->hostname, param->port);

	if (pthread_create (&thr_detector,
				&thr_att,
				detector_thread_fun, 
				param))
	{
		perror("Impossible de créer le thread\n");
		exit(-1);
	}

}