#include "mhshmkern.h"
#include "mhshmnetwork.h"

long id;
char *servhost;
int servport;
unsigned char *shared_page;
int running;
int lport;

void newmod (void);

void sighandler (int sig)
{
        switch (sig) {
        case SIGHUP:
                /* le noyau nous informe de quelquechose */
                fprintf (stderr, " SIGHUP \n");
                newmod ();
                break;
        case SIGINT:
        case SIGTERM:
                running = 0;
                break;
        default:
                fprintf (stderr, "Recu signal %d\n", sig);
        }
}

void newmod (void)
{
        unsigned long i, j;
        struct mhshm_net_packet packet;
        struct mhshm_net_mod *modnet = &packet.data.moddata;
        struct mhshm_kern_mod modker;
        
        packet.type = SENDMOD;
        packet.port = lport;
        modnet->nb_mod = 0;
        
        mhshm_getmod (id, &modker);
        /*
        if (!modker.nb_users) {
                running = 0;
                return;
        }
        */
        i = 0;
        j = 0;
        while (1) {
                if (j >= MHSHM_NBMODS_KERN) {
                        j = 0;
                        mhshm_getmod (id, &modker);
                }
                if (j >= modker.nb_mod) {
                        if (modnet->nb_mod)
                                send_packet (servhost, servport, &packet);
                        break;
                }
                
                if (i > MHSHM_NBMODS_NET) {
                        i = 0;
                        send_packet (servhost, servport, &packet);
                }
                modnet->nb_mod = i + 1;
                modnet->mod[i].offset = modker.offset[j];
                modnet->mod[i].data = shared_page[modker.offset[j]];
                i++;
                j++;
        }        
}

void daemon_noserv (void)
{
        fprintf (stderr, "\nLe serveur est mort !!!!\n\n");
        running = 0;
}

void daemon_newpage (unsigned char *page)
{
        static int initialized = 0;

        if (initialized)
                fprintf (stderr, "Erreur: reinitialisation de la page\n");
        initialized = 1;
        memcpy (shared_page, page, 4096);
}

void daemon_newmod (struct mhshm_net_mod *mod)
{
        unsigned i;

        for (i=0 ; i<mod->nb_mod ; i++) {
                shared_page[mod->mod[i].offset] = mod->mod[i].data;
        }
}

void server (int listened_socket)
{
        struct mhshm_net_packet packet;
        struct sockaddr_in sa;
        int salen;
        int sock_in;
        
        packet.type = NEWDAEMON;
        packet.port = lport;
        if (send_packet (servhost, servport, &packet))
                return;
        running = 1;
        
        for (;;) {
                /* on attend une connection entrante */
                /* evite d'utiliser le processeur a 100% */
                usleep (10000);
                
                salen = sizeof (sa);
                sock_in = accept (listened_socket, (struct sockaddr *)&sa, &salen);
                if ((sock_in == -1) && (errno == EAGAIN) && running)
                        continue;
                printf ("\n");
                
                if (!running)
                        break;
                
                if (sock_in == -1) {
                        fprintf (stderr, "Error: accept: %s\n", strerror (errno));
                        usleep (100000);
                        continue;
                }

                if (strcmp (inet_ntoa (sa.sin_addr), servhost)) {
                        fprintf (stderr, "Error: recu paquet de %s qui n'est pas le serveur %s\n", inet_ntoa (sa.sin_addr), servhost);
                        continue;
                }
                
                printf ("Connection de %s\n", servhost);
                if (read_packet (sock_in, &packet)) {
                        fprintf (stderr, "Erreur a la réception du paquet - paquet ignoré\n");
                        continue;
                }
                
                switch (packet.type) {
                case DISPMOD:
                        daemon_newmod (&packet.data.moddata);
                        break;
                case INITPAGE:
                        daemon_newpage (packet.data.page);
                        break;
                case SERVQUIT:
                        daemon_noserv ();
                        break;
                case ERROR:
                        fprintf (stderr, "Erreur du serveur\n");
                        break;
                default:
                        fprintf (stderr, "Error: recu paquet de type %d (%s)\n", (int)packet.type, pkt2str(packet.type));
                }
        }
        
        packet.type = DIEDAEMON;
        packet.port = lport;
        send_packet (servhost, servport, &packet);
}

char *inithost (char *hostname)
{
        struct hostent *phe;
        char *ret;
        struct in_addr ia;

        if (!(phe = gethostbyname (hostname))) {
                fprintf (stderr, "Error: gethostbyname: %s\n", hstrerror (h_errno));
                exit (1);
        }
        memcpy (&ia, phe->h_addr_list[0], sizeof (ia));
        ret = strdup (inet_ntoa (ia));
        if (!ret) {
                fprintf (stderr, "Error: malloc: %s\n", strerror (errno));
                exit (1);
        }
        return ret;
}

int main (int argc, char **argv)
{
        int listened_sock;
        
        if (argc < 5) {
                fprintf (stderr, "Usage : %s <id> <listenport> <servhost> <servport>\n", argv[0]);
                exit (1);
        }
        
        id = atol (argv[1]);
        lport = atol (argv[2]);
        servhost = inithost (argv[3]); /* nom->ip */
        servport = atoi (argv[4]);
        
        if (mhshm_create (id, &shared_page) == -1) {
                fprintf (stderr, "Erreur: mhshm_create: %s\n", strerror (errno));
                exit (1);
        }
        
        listened_sock = listen_socket (lport);
        
        signal (SIGINT, sighandler);
        signal (SIGTERM, sighandler);
        signal (SIGHUP, sighandler);

        fprintf (stderr, "Daemon for page %lu up on port %d, server is %s:%d\n", id, lport, servhost, servport);
        
        server (listened_sock);

        shutdown (listened_sock, SHUT_RDWR);
        close (listened_sock);
        
        mhshm_detach (shared_page);
        return 0;
}