#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

#define PORT 5000
#define BUFFER_SIZE 1024

int main() {
    int sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t addr_len = sizeof(client_addr);
    char buffer[BUFFER_SIZE];

    // Create socket
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        perror("Socket creation failed");
        exit(EXIT_FAILURE);
    }

    // Set up server address
    memset(&server_addr, 0, sizeof(server_addr)); // Clear structure
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;   // Bind to all available interfaces
    server_addr.sin_port = htons(PORT);         // Port number

    // Bind socket to the port
    if (bind(sock, (const struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("Bind failed");
        close(sock);
        exit(EXIT_FAILURE);
    }

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

    // Receive messages from client
    while (1) {
        int n = recvfrom(sock, (char *)buffer, BUFFER_SIZE, 0, (struct sockaddr *)&client_addr, &addr_len);
        buffer[n] = '\0'; // Null-terminate the received message
        printf("Client: %s\n", buffer);

        // Send a response to the client
        char *response = "Message received by server!";
        sendto(sock, (const char *)response, strlen(response), 0, (const struct sockaddr *)&client_addr, addr_len);
    }

    // Close socket
    close(sock);
    return 0;
}