//server code for creating and handling socket from
//lines 3-53
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define BUFFER_SIZE 1024
#define on_error(...) { fprintf(stderr, __VA_ARGS__); fflush(stderr); exit(1); }

int main (int argc, char *argv[]) {

    //use port 23 instead of a port specified by a user
    int port = 23;
    FILE *stream;

    int server_fd, client_fd, err, size;
    struct sockaddr_in server, client;
    char buf[BUFFER_SIZE], ret[BUFFER_SIZE];

    server_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (server_fd < 0) on_error("Could not create socket\n");

    server.sin_family = AF_INET;
    server.sin_port = htons(port);
    server.sin_addr.s_addr = htonl(INADDR_ANY);

    int opt_val = 1;
    setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt_val, sizeof opt_val);

    err = bind(server_fd, (struct sockaddr *) &server, sizeof(server));
    if (err < 0) on_error("Could not bind socket\n");

    err = listen(server_fd, 128);
    if (err < 0) on_error("Could not listen on socket\n");

    printf("Server is listening on %d\n", port);

    while (1) {
        socklen_t client_len = sizeof(client);
        client_fd = accept(server_fd, (struct sockaddr *) &client, &client_len);
        printf("Establishing connection with client...\n");
        if (client_fd < 0) on_error("Could not establish new connection\n")
        else printf("Connection established on port %d\n", port);

        while (1) {
            int read = recv(client_fd, buf, BUFFER_SIZE, 0);

            if (!read) break;
            if (read < 0) on_error("Client read failed\n");
            /*
            err = send(client_fd, buf, read, 0);
            if (err < 0) on_error("Client write failed\n");
            */
            printf("%s", buf);
            strncat(buf, "", 1);
            stream = popen("ls", "r"); //this is temporary until i figure out why the server wont process input properly

            while (fgets(buf, BUFFER_SIZE, stream) != NULL) {
                write(client_fd, stream, BUFFER_SIZE);
            }

            pclose(stream);

            //err = send(client_fd, buf, read, 0);
            //if (err < 0) on_error("Client write failed\n");
        }
    }

    return 0;
}