#pragma once

#include <iostream>
#include <fstream>
#include <stdio.h>
#include <vector>
#define _USE_MATH_DEFINES
#include <math.h>
#include <random>
#include <string>
#include <sstream>

#include "Particle.h"
#include "rnd.h"

using namespace std;


class DLASystem {
  private:
  // these are private variables and functions that the user will not see

    // list of particles
    vector<Particle*> particleList;
    int numParticles;

    /*
     * The probability that a particle will stick at a given site when adjacent.
     * */
    double stickProbability;

    // delete particles and clear the particle list
    void clearParticles();

    // size of cluster
    double clusterRadius;
    // these are related to the DLA algorithm
    double addCircle;
    double killCircle;
  
    // size of grid
    static const int gridSize = 1600;
    int **grid;  // this will be a 2d array that stores whether each site is occupied
  
    // random number generator, class name is rnd, instance is rgen
    rnd rgen;
  
    // CSV ouput
    ofstream csv;
  
    // number of particles at which the simulation will stop
    // (the value is set in constructor)
    int endNum;
  
    // the values of these variables are set in the constructor
    double addRatio;    // how much bigger the addCircle should be, compared to cluster radius
    double killRatio;   // how much bigger is the killCircle, compared to the addCircle

  
  public:
  // these are public variables and functions

    // update the system: if there is an active particle then move it,
    // else create a new particle (on the adding circle)
    void update();

    // is the simulation running
    bool running;
  
    // lastParticleIsActive is +1 if there is an active particle in the system, otherwise 0
    int lastParticleIsActive;
  
    // constructor
    explicit DLASystem(int maxParticles, const string &csvPath, double stickProbability);
    // destructor
    ~DLASystem();
  
    // delete all particles and reset
    void Reset();

    // this sets the seed for the random numbers
    void setSeed(int s) { rgen.setSeed(s); }

    // check whether we should stop (eg the cluster has reached the edge of the grid)
    int checkStop();

    // if pos is outside the cluster radius then set clusterRadius to be the distance to pos.
    void updateClusterRadius( double pos[] );

    // set and read grid entries associated with a given position
    void setGrid(double pos[], int val);
    int readGrid(double pos[]);

    // return the distance of a given point from the origin
    double distanceFromOrigin(double pos[]) {
      return sqrt( pos[0]*pos[0] + pos[1]*pos[1] );
    }

    // set whether there is an active particle in the system or not
    void setParticleActive()   { lastParticleIsActive = 1; }
    void setParticleInactive() { lastParticleIsActive = 0; }

    // add a particle at pos
    void addParticle(double pos[]);
    // add a particle at a random point on the addCircle
    void addParticleOnAddCircle();

    // assign setpos to the position of a neighbour of pos
    // which neighbour we look at is determined by val (=0,1,2,3)
    void setPosNeighbour(double setpos[], double pos[], int val);

    // this attempts to move the last particle in the List to a random neighbour
    // if the neighbour is occupied then nothing happens
    // the function also checks if the moving particle should stick.
    void moveLastParticle();

    // check whether the last particle should stick
    // currently it sticks whenever it touches another particle
    int checkStick();

    void exportData();
};