#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define BUFFER_SIZE	4096
#define BACKLOG_SIZE 	50
#define PHP_BIN 	"/usr/bin/php"
#define PHP_MODULE 	"./JabberExternModule.php"

void spawn_php(char *data);

int main(int argc, char** argv) {
	int port, sock, nsock;
	ssize_t datacount, ndata;
	size_t datasize = 0;
	char *data = NULL;
	struct sockaddr_in saddr;

	if (argc < 2) {
		fprintf(stderr,"USAGE : %s <listening_port>\n", argv[0]);
		return 2;
	}
	port = atoi(argv[1]);

	printf("Daemon serving at port %d\n", port);

	sock = socket(PF_INET, SOCK_STREAM, 0);
	if (sock < 0) {
		perror("socket failed to be created");
		return 1;
	}

	memset(&saddr, 0, sizeof(struct sockaddr_in));
	saddr.sin_family = AF_INET;
	saddr.sin_port = htons(port);
	inet_aton("0.0.0.0", &saddr.sin_addr);

	if(bind(sock, (struct sockaddr*)&saddr, sizeof(struct sockaddr_in)) < 0) {
		perror("socket failed to bind");
		return 1;
	}
	if (listen(sock, BACKLOG_SIZE) < 0) {
		perror("socket failed to start listening");
		return 1;
	}

	printf("Daemon connected, waiting for connections\n");
	while ((nsock = accept(sock, NULL, NULL)) >= 0) {
		printf("Incoming connection accepted\n");
		if (!data) {
			data = (char*)calloc(BUFFER_SIZE, sizeof(char));
			datasize = BUFFER_SIZE * sizeof(char);
		}
		else {
			memset(data,0,datasize);
		}
		datacount = 0;
		do {
			ndata = recv(nsock, data+datacount, datasize, 0);
			datacount += ndata;
			if (datacount >= datasize) {
				data = (char*)realloc(data,datasize+BUFFER_SIZE);
				memset(data+datasize,0,BUFFER_SIZE);
				datasize += BUFFER_SIZE;
			}
		} while (ndata > 0);
		
		/* no need to maintain connection */
		close(nsock);
		if (datacount > 0)
			spawn_php(data);
		else
			perror("Failed getting a command, connection shut down");
		printf("Waiting for another job to connect\n");
	}

	perror("Connexion lost, stopping daemon");
	return 1;
}

void spawn_php(char *data) {
    int cpid = fork();
    if (cpid == 0) {
      execlp(PHP_BIN, "-f", PHP_MODULE, data, NULL);
      perror("Couldn't spawn child process");
      exit(1);
    }
    else if (cpid < 0) {
      fprintf(stderr, "Couldn't fork : restarter will now shut down\n");
      exit(1);
    }
}