#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>

int main(int argc, char **argv)
{
    int ssock, csock, i;
    static char buff[256];
    ssize_t nbytes;
    struct sockaddr_in saddr;

    memset(&saddr, 0, sizeof(saddr));
    saddr.sin_family = AF_INET;
    saddr.sin_port = htons(6666);

    signal(SIGPIPE, SIG_IGN);

    printf("Server started...\n");

    if ((ssock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        printf("socket() error. (%d) %s\n", errno, strerror(errno));
        exit(1);
    }
    printf("Created SOCK_STREAM socket\n");

    if (bind(ssock, (struct sockaddr*)&saddr, sizeof(saddr)) == -1) {
        printf("bind() error. (%d) %s\n", errno, strerror(errno));
        close(ssock);
        exit(1);
    }
    printf("Bound to localhost:6666\n");

    if (listen(ssock, 1) == -1) {
        printf("listen() error. (%d) %s\n", errno, strerror(errno));
        close(ssock);
        exit(1);
    }

    printf("waiting for connection...\n");
    csock = accept(ssock, NULL, NULL);

    if (csock == -1) {
        printf("accept() error. (%d) %s\n", errno, strerror(errno));
        close(ssock);
        exit(1);
    }
    printf("Client connected!\n");
    printf("Waiting for some data from client\n");

    while ((nbytes = recv(csock, buff, sizeof(buff), 0)) > 0) {
            printf("Received: \"%s\"\n", buff);
    }

    if (nbytes < 0) {
        printf("recv() error. (%d) %s\n", errno, strerror(errno));
        close(ssock);
        close(csock);
        exit(1);
    } else if (nbytes == 0) {
        printf("Received EOF\n");
        printf("Sending msg to client: \"MSG from server\"\n");
        if ((nbytes = send(csock, "MSG from server", sizeof("MSG from server"), 0)) <= 0) {
            printf("send() error. (%d) %s\n", errno, strerror(errno));
            close(ssock);
            close(csock);
            exit(1);
        }
    }

    printf("sleep(5)\n");
    sleep(5);
    
    i = 1;
    while (1) { 
        printf("Sending %d msg to client: \"MSG from server\"\n", i);
        nbytes = send(csock, "MSG from server", sizeof("MSG from server"), 0);
        printf("try #%d send() result: (%d) %s\n",i ,errno, strerror(errno));
        if (nbytes <= 0)
            break;
        ++i;
    }

    printf("Server exiting...\n");
    close(ssock);
    close(csock);
    return 0;
}