#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/select.h>

#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/wait.h>

#define PORT 5000

int serve(int sd);
int run = 1;
int main () {
    int lsd;
    int ret;
    struct sockaddr_in sin;
    int sin_size=sizeof(sin);
    int sd;
    int enable=1;
    char answr;
    int flag=0;


    if ((lsd=socket(AF_INET, SOCK_STREAM, 0))<0) {
        fprintf(stderr,"cannot screat listeing socket");
        perror(0);
        exit(1);
    }
    setsockopt(lsd,SOL_SOCKET,SO_REUSEADDR,&enable,sizeof(int));
    printf("Socket will bind to port %d\n", PORT);
    sin.sin_family=AF_INET;
    sin.sin_port=htons(PORT);
    sin.sin_addr.s_addr=htonl(INADDR_ANY);
    if (bind(lsd,&sin,sin_size)<0) {
        fprintf(stderr,"cannot bind listening socket");
        perror(0);
        exit(1);
    }
    if (listen(lsd,15)<0) {
        fprintf(stderr,"cannot liste on socket");
        perror(0);
        exit(1);
    }
    //int run = 1;
    while(run) {
        printf("Server: I am ready for connections\n");
        if ((sd=accept(lsd,&sin,&sin_size))<0)
            exit(errno);
            printf("Incoming!Accept?(y/n)\n");
            scanf("%c", &answr);
            while ((answr!='Y') && (answr!='y') && (answr!='n') && (answr!='N'))
                scanf("%c",&answr);
            if ((answr=='y') || (answr=='Y')) {
                write(sd,"accept",sizeof("accept"));
                printf("connection accepted\n");
                ret=fork();
                if (ret==0) serve(sd); else wait(NULL);
            }
            else if ((answr=='n') || (answr='N')) {
                write(sd,"quit",sizeof("quit"));
                printf("connection refused\n");
            }

        shutdown(sd,2);
        close(sd);
    }
        shutdown(lsd,2);
        close(lsd);
    return 0;
}


int serve (int sd) {
    char c;
    int a;
    int i=0;
    FILE *rcv;
    rcv=fopen("receiveme","w");
    if  (rcv==NULL) {
        printf("sfalma stin dimiourgia arxeiou\n");
        return -1;
    }
    sleep(1);
    a=read(sd,&c,sizeof(char));
    printf("receiving...");
    while (a!=0) {
        putc(c, rcv);
        a=read(sd,&c,sizeof(char));
        i++;
    }
    printf("Complete!\n");
    fclose(rcv);
    shutdown(sd,2);
    close(sd);

    char ch = getchar();
    if (ch == 'q')
        run = 0;
    exit(0);
}