#include "mbed.h"
#include "EthernetInterface.h"

#define SERVER_PORT             54322
#define MAX_NUM_OF_CONNECTIONS  10

DigitalOut led1(LED1);
DigitalIn alert_button (p23);
Ticker timer;

bool flag = false;
int num_connections = 0;

//Toggle the flag for checking new connections
void check()
{
    if (num_connections < MAX_NUM_OF_CONNECTIONS)
        flag = true;
}

int main (void)
{
    printf("Initializing the Ethernet interface...\n");
    EthernetInterface eth;
    if (eth.init() < 0)
        printf("---Could not initialize the Ethernet interface\n");


    printf("Connecting...\n");
    if(eth.connect() < 0)
        printf("---Could not connect\n");

    printf("\nIP Address is %s\n", eth.getIPAddress());


    printf("\nInitializing and binding the TCP socket...\n");
    TCPSocketServer server;
    if (server.bind(SERVER_PORT) < 0)
        printf("---Could not initialize or bind\n");


    printf("Starting the TCP socket for listening...\n");
    server.set_blocking(false);
    if (server.listen() < 0)
        printf("---Could not start listening\n");

    TCPSocketConnection clients[MAX_NUM_OF_CONNECTIONS];
    bool clients_status[MAX_NUM_OF_CONNECTIONS];

    timer.attach(&check, 5.0);

    printf("\nReady\n");

    char buffer[] = "ALERT!!!";

    while (true) {
        if (flag == true) {
            led1 = 1;

            int index_to_connect = 0;
            bool done_finding = false;

            // Find an empty element for assigning a new connection to it
            while(!done_finding) {
                if (clients_status[index_to_connect] == false)
                    done_finding = true;
                else
                    index_to_connect++;
            }

            // Accept the new connection if there is one pending
            if (server.accept(clients[index_to_connect]) == 0) {
                clients[index_to_connect].set_blocking(false);
                printf("Connected to %s\n", clients[index_to_connect].get_address());

                clients_status[index_to_connect] = true;
                num_connections++;
            }

            led1 = 0;
            flag = false;
        }

        // Send an alert to connected clients when the button is pressed
        if (alert_button == 1 && num_connections > 0) {
            int index_to_send = 0;
            int num_disconnections = 0;
            bool done_sending = false;

            while (!done_sending) {
                if (clients_status[index_to_send] == true) {
                    int result = clients[index_to_send].send(buffer, sizeof(buffer));

                    if (result < 0) {
                        printf("%s has disconnected\n", clients[index_to_send].get_address());
                        clients[index_to_send].close();
                        clients_status[index_to_send] = false;
                    } else
                        printf("Sent to %s\n", clients[index_to_send].get_address());
                }

                if (index_to_send > MAX_NUM_OF_CONNECTIONS)
                    done_sending = true;
                else
                    index_to_send++;
            }

            if (num_disconnections > 0)
                num_connections -= num_disconnections;

            while (alert_button == 1) {} // Stay looping until the button is relased
        }
    }
}