/**
 * Jednoduchý TCP klient
 *
 * Pošle správu serveru a vypíše odpoveď (echo).
 *
 * Spustenie: ./client "Ahoj svet"
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 8080
#define SERVER_IP "127.0.0.1"
#define BUFFER_SIZE 1024

int main(int argc, char *argv[]) {
    const char *message = (argc > 1) ? argv[1] : "Ahoj, server!\n";
    char buffer[BUFFER_SIZE];

    // 1. Otvorenie soketu
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    struct sockaddr_in server_addr = {
        .sin_family = AF_INET,
        .sin_port   = htons(PORT),
    };
    inet_pton(AF_INET, SERVER_IP, &server_addr.sin_addr);

    // 2. Spojenie so serverom
    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    // 3. Odoslanie správy
    write(sockfd, message, strlen(message));
    printf("Odoslané: %s", message);

    // 4. Prijatie odpovede
    int bytes = read(sockfd, buffer, BUFFER_SIZE - 1);
    if (bytes > 0) {
        buffer[bytes] = '\0';
        printf("Odpoveď:  %s", buffer);
    }

    close(sockfd);
    return 0;
}