#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>

int server_tcp() {
    char* hostname = "localhost";
    char* port = "9004";

    struct addrinfo hints = {0};
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;
    hints.ai_flags = AI_PASSIVE;

    struct addrinfo* res;
    int err_ret = getaddrinfo(hostname, port, &hints, &res);
    if (err_ret != 0) {
        fprintf(stderr, "getaddrinfo got error code: %d\n", err_ret);
        return -1;
    }

    int sfd = -1;
    for (struct addrinfo* i = res; i != NULL; i = i->ai_next) {
        sfd = socket(i->ai_family, i->ai_socktype, i->ai_protocol);
        if (sfd == -1) {
            perror("socket");
            continue;
        }

        int err_ = bind(sfd, i->ai_addr, i->ai_addrlen);
        if (err_ == -1) {
            perror("bind server tcp");
            close(sfd);
            continue;
        }

        err_ = listen(sfd, 100);
        if (err_ == -1) {
            perror("listen server tcp");
            close(sfd);
            continue;
        }

        break;
    }

    freeaddrinfo(res);
    return sfd;
}

void* echo_server(int sfd_server, int sfd_client) {
    printf("socket server: %d\n", sfd_server);
    printf("socket client: %d\n", sfd_client);

    char buf[1000];
    int len;
    while (1) {
        len = read(sfd_client, buf, 1000);

        if (len == 0) {
            continue;
        }

        printf("Got length: %d\n", len);
        printf("Server received message: `%s`\n", buf);
        break;
    }

    char* new_msg = "Some new string from the server";
    write(sfd_client, new_msg, strlen(new_msg) + 1);

    close(sfd_client);
    return NULL;
}


int main(void) {
    int sfd_server = server_tcp();
    int sfd_client = accept(sfd_server, NULL, NULL);

    if (sfd_client == -1) {
        perror("accept server tcp");
        return 1;
    }

    echo_server(sfd_server, sfd_client);

    close(sfd_server);
}