/* 
 * server.c - demo program that connects listens for connections on PORT
 *            receives message from client, responds with message back to client 
 *            this program has only minor edits to the original at https://www.geeksforgeeks.org/socket-programming-cc/
 *            works with client.c
 *            first start the server running, then in a separate terminal start the client running 
 *
 * usage: ./server
 * compile: gcc -o server server.c
 *
 *
 * author:  Geeks for Geeks
            Tim Pierson, Fall 2022, minor edits
 * CS 50, Fall 2022
 */
#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

const int PORT = 8080;

/** Set up server socket to listen for client connections
 * When connection made, read message from client
 * respond to client with message from this server
 * 
 * int num_players - max number of connections to accept
 */

void get_players(int num_players) {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[1024] = { 0 };
    char* hello = "Hello from server";
  
    printf("Setting up socket\n");
    // Creating socket file descriptor
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
  
    // Attaching socket to the PORT
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))) {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    
    // Binding socket to the PORT
    if (bind(server_fd, (struct sockaddr*)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    if (listen(server_fd, num_players) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    printf("Waiting for connection... ");
    fflush(stdout); //ensure line above prints before waiting for connection
    if ((new_socket = accept(server_fd, (struct sockaddr*)&address, (socklen_t*)&addrlen)) < 0) {
        printf("\n");
        perror("accept");
        exit(EXIT_FAILURE);
    }
    printf("Someone connected\n");
    valread = read(new_socket, buffer, 1024);
    if (valread < 0) {
        perror("reading message");
        exit(EXIT_FAILURE);
    }
    printf("Message from client: %s\n", buffer);
    printf("Sending %s to client\n",hello);
    send(new_socket, hello, strlen(hello), 0);
    printf("Message sent\n");
    
  // closing the connected socket
    close(new_socket);
  // closing the listening socket
    shutdown(server_fd, SHUT_RDWR);
}


int main(int argc, char* argv[]) {
     int num_players = 1;
     get_players(num_players);

    return 0;
}