#include <sys/types.h>
#include <sys/socket.h>
#include <pthread.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <netinet/in.h>

#define BUFSIZE 128
void *worker(void *arg){
    int socket=*(int *)arg;
    char buf[BUFSIZE];
    unsigned int count = 0;
    char *filename = 0;

    while (1) {
	ssize_t ret;
	ret = read(socket,buf+count,BUFSIZE-count);
	printf("Read ret = %d\n",ret);                                         
        fflush(stdout);   
	if (ret <= 0)
	    goto out;
	if (ret > 0)
	    count+=ret;
	if (count > 0) 
	    if (memchr(buf,0,count)!=0) {
		printf("got fn=(%s),count=%d\n",buf,count);                                         
    		fflush(stdout);   
		filename = (char *)malloc(strlen(buf));
		if (filename==0)
		    goto out;
		strcpy(filename,buf);
		break;
	    }
	if (count == BUFSIZE)
	    goto out;	
    }
    
    int ret = htonl(-1);

    assert(BUFSIZE>(20+sizeof(int)));
    
    memset(buf+sizeof(int),0,20); 	
    
    if (access(filename,R_OK) == 0) {
	struct stat st;
	int fd;
	
	if (stat(filename,&st) == 0)
	    ret = htonl(st.st_size);
	
	if ((fd = open(filename,O_RDONLY)) != -1) {
	    read(fd,buf+sizeof(int),20);
	    close (fd);
	}
    }
    
    printf("File access = %d\n",ntohl(ret));
    fflush(stdout);
    
    memcpy(buf,&ret,sizeof(int));
    sleep(3);
    int tosend = 20+sizeof(int);
    printf("Tosend = %d\n",tosend);
    fflush(stdout);
    while (tosend>0) {
	int retval = write(socket,buf+((20+sizeof(int))-tosend),tosend);
	printf("Write retval = %d\n",retval);
	fflush(stdout);
	if (retval < 0)
	    goto out;
	tosend-=retval;    
    }
    
out:
    printf("Thread bye\n");
    fflush(stdout);
    
    close(socket);
    if (filename)
	free(filename);
    free(arg);	
    return 0;
}

int main (int argc, char **argv) {
    int sock;
    
    if ((argc != 2)||(atoi(argv[1])==0)) {
	fprintf(stderr,"Uzycie: %s port\n",argv[0]);
	return -1;
    }
        
    sock = socket(PF_INET6,SOCK_STREAM,0);
    if (sock == -1){
	perror("socket");
	return -1;
    }
    do {
	int opt=1;
	if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(int))!=0) {
	    perror("setsockopt");
	    return -1;
	}
    } while(0);
    
    do {
	struct sockaddr_in6 sa;
	memset(&sa,0,sizeof(sa));
//	sa.sin6_len = sizeof(sa);
	sa.sin6_family = AF_INET6;
	sa.sin6_port = htons(atoi(argv[1]));
	sa.sin6_addr = in6addr_any;
	
	if (bind(sock,(struct sockaddr *) &sa,sizeof(sa))!=0) {
	    perror("bind");
	    return -1;
	}
    } while(0);
    
    if (listen(sock,5)!=0) {
	    perror("listen");
	    return -1;
    }
    
    while (1) {
	int newsock = accept(sock,0,0);
	if (newsock == -1) {
	    perror("accept");
	    return -1;	
	}
	
	printf("New connection\n");
	fflush(stdout);
		
	int *arg = malloc(sizeof(int));
	if (arg == 0) {
	    perror("malloc");
	    close(newsock);
	    continue;
	}
	*arg=newsock;
	
	pthread_t tid;

	if (pthread_create(&tid,0,worker,arg)!=0) {
	    perror("pthread_create");
	    close(newsock);
	    free(arg);
	    continue;
	}
	printf("Tid %d\n",tid);
	fflush(stdout);
    }
    return 0;
}