#include<iostream>
#include<cmath>
#include<conio.h>
#include<stdlib.h>
#include<ctime>
using namespace std;
class Q4{
	public:
		int a,m,s,*arr,ws;
		Q4();
		void correctframe(int);
		void acknowledgementlost(int);
		void framelost(int);
		void delayinframe(int);
		void window(int);
		void resend(int);
};
Q4::Q4(){
	cout<<"Enter the number of frames: ";
	cin>>a;
	cout<<"Enter the window size(value of m): ";
	cin>>m;
	s=pow(2,m-1);
	cout<<"Window size:"<<s<<endl;
	ws=pow(2,m);
	arr=new int[s];
	cout<<"Sequence of sending frame :"<<ws<<endl;
	cout<<"Sequencial numbers of rame to be used :";
	for(int i=0;i<ws;i++)
	{
		cout<<i<<"  ";
	}cout<<endl;
}
void Q4::correctframe(int i)
{
		cout<<"\t\t\tRecieving Frames from Sender"<<endl;
		cout<<"\t\t\t\tSending acknowledgement to sender"<<endl;
		getch();
		cout<<"Acknowledgement recieved for frame f"<<(i-1)%ws<<"\n";
		getch();
		
}
void Q4::acknowledgementlost(int i)
{
			cout<<"\t\t\tRecieving Frames from Sender"<<endl;
			cout<<"\t\t\t\tSending acknowledgement to sender"<<endl;
			getch();
			cout<<"\t\t   Acknowledgement lost by the reciever for frame f"<<(i-1)%ws<<"\n";
			getch();
	    	resend(i);
	    	getch();
	    	cout<<"\t\t\t\tSending acknowledgement to sender"<<endl;
	    	cout<<"Acknowledgement recieved for frame f"<<(i-1)%ws<<"\n";
	    	getch();
	    	cout<<"Sliding Window....Sending next frame"<<endl;
	    	getch();
}
void Q4::framelost(int i)
{
			cout<<"\t\t\tRecieving Frames from Sender"<<endl;
			cout<<"\t\t   Frame f"<<(i-1)%ws<<" is lost\n";
			getch();
	    	resend(i);
	    	getch();
	    	cout<<"\t\t\t\tSending acknowledgement to sender"<<endl;
			getch();
	    	cout<<"Acknowledgement recieved for frame f"<<(i-1)%ws<<"\n";
	    	getch();
	    	cout<<"Sliding Window....Sending next frame"<<endl;
	    	getch();
}
void Q4::delayinframe(int i)
{
			cout<<"\t\t\tRecieving Frames from Sender"<<endl;
			cout<<"\t\t There is a delay in sending the frame f"<<(i-1)%ws<<" from the sender\n";
			getch();
	    	resend(i);
	    	getch();
	    	cout<<"\t\t\t\tSending acknowledgement to sender"<<endl;
			getch();
	    	cout<<"Acknowledgement recieved for frame f"<<(i-1)%ws<<"\n";
	    	getch();
	    	cout<<"Sliding Window....Sending next frame"<<endl;
	    	getch();
}
void Q4::resend(int i){
	cout<<"\nFrames in the current window are: ";
	for(int j=0;j<s;j++){
	    if((j+i)<=a){
	    	arr[j]=j+i;
	        cout<<arr[j]<<" ";	
	    }
	}
	cout<<endl;
	getch();
		cout<<"\nSequencial number Of Frames in window: ";
	for(int j=0;j<s;j++){
	    if((j+i)<=a){
	    	arr[j]=j+i;
	        cout<<(i+j-1)%ws<<" ";	
	    }
	}
	cout<<endl;
	getch();
	   /* for(int j=0;j<s;j++){
	    	arr[j]=j+i;
	    	if((j+i)<=a){
	            cout<<"Frame f"<<(j+i-1)%ws<<" \n";	
	    	}
	    }*/
	    int j=0;
	   if(j+i<=a)
	   	{
	    cout<<"Resending frame f"<<(i-1)%ws<<endl;
	    getch();
	    j++;
		}
}
void Q4::window(int i){
	cout<<endl;
	for(int j=0;j<s;j++){
	    if((j+i)<=a){
			arr[j]=j+i;
	  		if(i==1){
	            cout<<"Sending frame f"<<(j+i-1)%ws<<"\n";
    		}	
	   	}
	}
	if(i!=1&&i<=a-s+1){
	    cout<<"Sending frame f"<<arr[s-1]<<"\n";
		getch();
	}
	
}
int main(){
	Q4 obj;
	int r;
	srand(time(0));
	cout<<"SENDER'S SIDE\n						RECIEVER'S SIDE"<<endl;
	for(int i=1;i<=obj.a;i++){
	    r=rand()%4;
	    obj.window(i);
	switch(r){
		case 0:{
			obj.correctframe(i);
			break;
		}
		case 1:{
			obj.acknowledgementlost(i);
			break;
		}
		case 2:{
			obj.framelost(i);
			break;
		}
		case 3:{
			obj.delayinframe(i);
			break;
		}
		default:
			cout<<"Invalid choice\n";
		}
	}
	cout<<endl<<endl<<"All frames are sent successfully";
	getch();
	return 0;
}