#include <asm-generic/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>

// Server starten: nc -lp1337
// Dann Client (dieses Programm) starten
int main() {
  int sock = socket(AF_INET6, SOCK_STREAM, 0);
  // Fehlerbehandlung
  struct sockaddr_in6 addr = {
      .sin6_family = AF_INET6,
      .sin6_port = htons(1337),
      .sin6_addr = in6addr_any,
  };
  int flag = 1;
  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(flag));
  // Fehlerbehandlung
  (void)bind(sock, (struct sockaddr*)&addr, sizeof(addr));
  listen(sock, SOMAXCONN);

  while (1) {
    int client = accept(sock, NULL, NULL);

  /* /\*   printf("Client connected.\n"); *\/ */
    
  /* /\* FILE *rx = fdopen(client, "r"); *\/ */
  /* /\* // Fehlerbehandlung *\/ */
  /* /\* int copy = dup(client); *\/ */
  /* /\* // Fehlerbehandlung *\/ */
  /* /\* FILE *tx = fdopen(copy, "w"); *\/ */
  /* /\* // Fehlerbehandlung *\/ */
  
  /* /\* int upper = 2; *\/ */
  /* /\* int read; *\/ */
  /* /\* while ((read = fgetc(rx)) != EOF) { *\/ */
  /* /\*   if (upper == 2) { *\/ */
  /* /\*     if (read == 'u') { *\/ */
  /* /\*       upper = 1; *\/ */
  /* /\*     } else if (read == 'l') { *\/ */
  /* /\*       upper = 0; *\/ */
  /* /\*     } else { *\/ */
  /* /\*       fprintf(stderr, "Invalid char from client"); *\/ */
  /* /\*       // FILE* schließen, weitermachen *\/ */
        // nicht
        // exit(EXIT_FAILURE);
      }
      continue;
    }

    if (upper) {
      fputc(toupper(read), tx);
    } else {
      fputc(tolower(read), tx);
      // FB
    }

    fflush(tx);
    // Fehlerbehandlung aller IO-Funktion
  }

  // Ressourcen freigeben
      
  }

  

}