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

/* Unix sockets need a path */
#define SOCK_PATH "/tmp/demosocket"
#define BUF_SIZE 128

char buf[BUF_SIZE];

int main(void) {
    struct sockaddr_un addr;
    int server_fd, client_fd;

    char *msg = "Hello\n";
    memcpy(buf, msg, strlen(msg));

    // Unlink this in case its still around
    unlink(SOCK_PATH);

    server_fd = socket(AF_UNIX, SOCK_STREAM, 0);
    if (server_fd == -1) {
        perror("Error: Could not open socket...\n");
        exit(EXIT_FAILURE);
    }

    // Wipe this for security
    memset(&addr, 0, sizeof(struct sockaddr_un));
    addr.sun_family = AF_UNIX;
    snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", SOCK_PATH);

    if (bind(server_fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        perror("Could not bind server...\n");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    if (listen(server_fd, 1) == -1) {
        perror("Listen");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    printf("Server listening on %s...\n", SOCK_PATH);

    while (1) {
        // This will block until a message is recieved
        client_fd = accept(server_fd, NULL, NULL);
        if (client_fd == -1) {
            perror("accept");
            close(server_fd);
            exit(EXIT_FAILURE);
        }

        ssize_t received = recv(client_fd, buf, BUF_SIZE - 1, 0);
        if (received > 0) {
            buf[received] = '\0';
            printf("Server got: %s\n", buf);

            // Send a reply
            const char *reply = "pong!\n";
            send(client_fd, reply, strlen(reply), 0);
        } else {
            perror("recv");
        }
    }

    close(client_fd);
    close(server_fd);
    unlink(SOCK_PATH);
    return 0;
}