#define SOURCEMACLENGHT 6
#define USERALIASLENGTH 12



#include "pcap.h"
#include "conio.h"
#include <stdlib.h>
#include <stdio.h>
#include <iostream>

using namespace std;



pcap_if_t *alldevs;
pcap_if_t *d;
pcap_t *fp;
pcap_t *adhandle;
char errbuf[PCAP_ERRBUF_SIZE];

int roomNumber;
int interfaceNumber;
int sourceMac[SOURCEMACLENGHT];
bool hasRoomAvailable;
bool hasSameMac;
char userAlias[USERALIASLENGTH];

int res;
struct pcap_pkthdr *header;
const u_char *pkt_data;


void ListAllDevices()
{
    cout << "-> Type an interface number: " << endl << endl;

    if(pcap_findalldevs(&alldevs, errbuf) == -1)
    {
        cout << stderr << "-> Error in pcap_findalldevs: " << errbuf << endl;

        exit(1);
    }

    int index = 1;

    for(d = alldevs; d; d = d -> next)
    {
        cout << index++ << ". " << d -> name;

        if(d -> description)
        {
            cout << "\t" << d -> description << endl;
        }
        else
        {
            cout << "-> No description available." << endl;
        }
    }

    if(index == 0)
    {
        cout << "-> No interfaces found! Make sure WinPcap is installed." << endl;
    }

    cout << "-> Your choice: " << endl;
    cin >> interfaceNumber;

    if(interfaceNumber < 1 || interfaceNumber > index)
    {
        cout << "-> Error. Interface number out of range." << endl;

        /// Free the device list.
        pcap_freealldevs(alldevs);
    }

    /// Jump to the selected adapter.
    for(d = alldevs, index = 0; index < interfaceNumber - 1; d = d -> next, index++);

    /// Open the device.
    if((adhandle = pcap_open_live(
                                    d -> name,  /// Name of the device.
                                    65536,      /// Portion of the packet to capture. 65536 guarantees that the whole packet will be captured on all the link layers.
                                    1,          /// Promiscuous mode.
                                    1000,       /// Read timeout. Authentication on the remote machine.
                                    errbuf      /// Error buffer.
                                    )) == NULL)
    {
        cout << stderr << "-> Error. Unable to open the adapter." << d -> name << " is not supported by WinPcap." << endl;

        /// Free the device list.
        pcap_freealldevs(alldevs);
    }

    /// At this point, we don't need any more the device list. Free it.
    pcap_freealldevs(alldevs);

    cout << endl;
}

bool CheckSourceMac()
{
	for (int i = 0; i < SOURCEMACLENGHT; i++)
	{
		if (sourceMac[i] < 0 || sourceMac[i]>255)
		{
		    cout << "-> Not a valid MAC Address, enter a valid one. " << endl;
			return false;
		}
	}

	return true;
}

void SetUserData()
{

	do
	{
		cout << "-> Type Source MAC (XX:XX:XX:XX:XX:XX) :" << endl;
		scanf("%x:%x:%x:%x:%x:%x", &sourceMac[0], &sourceMac[1], &sourceMac[2], &sourceMac[3], &sourceMac[4], &sourceMac[5]);
	} while(!CheckSourceMac());


    do
    {
        cout << "-> Write the room number: " << endl;
        cin >> roomNumber;

        if(roomNumber >= 0 && roomNumber <= 255)
        {
            hasRoomAvailable = true;
        }
        else
        {
            hasRoomAvailable = false;
            cout << "-> Select another room." << endl;
        }
    }
    while(hasRoomAvailable == false);

    cout << "-> Type an alias: " << endl;

    fflush(stdin);
    gets(userAlias);
    fflush(stdin);

    if(strlen(userAlias) < USERALIASLENGTH)
    {
        for(int i = strlen(userAlias); i < USERALIASLENGTH; i++)
        {
            userAlias[i] = '\0';
        }
    }

    cout << endl;
}




void ShowTypedData()
{
    cout << "-> Data typed: " << endl << endl;

    cout << "-> Origin MAC Address: " << endl;

    for(int i = 0; i < SOURCEMACLENGHT; i++)
    {
        printf("%x", sourceMac[i]);

        if(i + 1 == SOURCEMACLENGHT)
        {
            cout << endl;
        }
        else
        {
            cout << ":";
        }
    }

    cout << "-> Room Number: " << endl;

    cout << roomNumber << endl;

    cout << "-> Alias: " << endl;

    for(int i = 0; i < sizeof(userAlias); i++)
    {
        cout << userAlias[i];

        if(i + 1 == sizeof(userAlias))
        {
            cout << endl << endl;
        }
    }
}


void SendMessage(pcap_t *adhandle, int *sourceMac, int roomNumber, char *userAlias)
{
	char textMsg[1000];
	int newMessageSize = 0;

	fflush(stdin);
	gets(textMsg);
	fflush(stdin);

	if (strlen(textMsg) < 37)
	{
		for (int i = strlen(textMsg); i <= 37; i++)
		{
			textMsg[i] = '\0';
		}

		newMessageSize = 37;
	}
	else if (strlen(textMsg) > 993)
	{
		newMessageSize = 993;
	}
	else
	{
		newMessageSize = strlen(textMsg);
	}

	u_char packet[newMessageSize + 23];

	for (int i = 0; i <= 5; i++)
	{
		packet[i] = 255;
	}

	for (int i = 6, counter = 0; i <= 11; i++, counter++)
	{
		packet[i] = sourceMac[counter];
	}

	packet[12] = 0x07;
	packet[13] = 0x00;
	packet[14] = roomNumber;

	for (int i = 15, counter = 0; i <= 27; i++, counter++)
	{
		packet[i] = userAlias[counter];
	}

	for (int i = 0; i < newMessageSize; i++)
	{
		packet[i + 27] = (u_char)textMsg[i];
	}

	/// Send down the packet.
	if (pcap_sendpacket(
		adhandle,       /// Adapter.
		packet,         /// Buffer with the packet.
		sizeof(packet)  /// Size.
	) != 0)
	{
		cout << stderr << "-> Error sending the packet: " << pcap_geterr(adhandle) << endl;
	}

	for (int i = 15; i <= 22; i++)
	{
		cout << packet[i];
	}

	cout << " >> ";

	for (int i = 23; i < sizeof(packet); i++)
	{
		cout << packet[i];
	}

	cout << endl;
}

void ListenMessages(struct pcap_pkthdr *header, const u_char *pkt_data)
{
	for (int i = 15; i <= 22; i++)
	{
		cout << pkt_data[i];
	}

	cout << " >> ";

	for (int i = 23; i < header->len; i++)
	{
		cout << pkt_data[i];
	}

	cout << endl;
}


void ChatSendRecieve()
{

    cout << "-> Type the message: " << endl;

    while((res = pcap_next_ex(adhandle, &header, &pkt_data)) >= 0)
    {
        if(kbhit())
            SendMessage(adhandle, sourceMac, roomNumber, userAlias);

		if (res == 0)
			continue;

        for(int i = 0; i < SOURCEMACLENGHT; i++)
        {
            if(sourceMac[i] == pkt_data[i + SOURCEMACLENGHT])
                hasSameMac = true;

            else
            {
                hasSameMac = false;
                break;
            }
        }

        if(pkt_data[12] == 07 && pkt_data[13] == 00 && pkt_data[14] == roomNumber && !hasSameMac)
        {
            ListenMessages(header, pkt_data); //We check here if the packet is from the same room number and doesn't have the same mac address.
        }
    }

    if(res == -1)
    {
        cout << "-> Error reading the packets: " << pcap_geterr(adhandle) << endl;
    }

    pcap_close(fp);
}


int main()
{
    ListAllDevices();
	SetUserData();
	ShowTypedData();
	ChatSendRecieve();

	return 0;
}