//------------------------------------------------------------------------
// Author:      Oliver Merle (Oliver.Merle@exp2.physik.uni-giessen.de)
// Changes:     Mustafa Schmidt (Mustafa.A.Schmidt@physik.uni-giessen.de)
// Date:        30.11.2015
// Description: Class to emulate noise for the readout electronics
//------------------------------------------------------------------------

#ifndef PNDDISCNOISEGENERATION_H
#define PNDDISCNOISEGENERATION_H


#include "TClonesArray.h"


class PndDiscDigitizedHit;



class PndDiscNoiseGeneration
{
public:
    PndDiscNoiseGeneration();
    ~PndDiscNoiseGeneration();
    
    // Initialization:

    /// Set the number of sensors for the whole apparatus
    void SetNumberOfSensors(int n_detectors_, int n_readout_modules_, int n_sensors_);
    /// Set the pixel grid on the sensors
    void SetSensorGrid(double sensor_width_, double sensor_height_, int n_pixel_x_, int n_pixel_y_);
    /// Set a logical tiling (used for dead time handling)
    void SetSensorTiling(int sensor_tiles_x, int sensor_tiles_y);
    void SetPerCellDCR(double dcr_Hz) { dcr_per_pixel = dcr_Hz*1E-9; }

    // Noise generation and access to noise digits:
    int GenerateNoise(double t_start_ns, double t_end_ns);    ///< Generate noise pattern in time window given by t_start, t_end
    PndDiscDigitizedHit * GetNextNoiseDigit();              ///< Iterate over all generated hits.
    void Clear();                                             ///< Clears the digit buffer

private:
    bool GetPixelPosition(int n_pixel, double & pos_x, double & pos_y);

protected:
    TClonesArray * noise_digits;        ///< Memory pool to store the digits
    int current_index;                  ///< current index in pool (used in iteration)

    int n_detectors;                    ///< number of detectors
    int n_readout_modules;              ///< number of readout modules on a detector
    int n_sensors;                      ///< number of sensors (untiled) at a readout module
    int n_sensor_tiles_x;               ///< number of sensor tiles = number of dies 
    int n_sensor_tiles_y;               ///< number of sensor tiles = number of dies

    double half_sensor_width;
    double half_sensor_height;
    int    n_pixel_x;
    int    n_pixel_y;
    int    n_pixel_total;

    double pitch_x;
    double pitch_y;

    double dcr_per_pixel; // pixel means a single SPAD here - unit: dark counts / ns
};

#endif // PNDDISCNOISEGENERATION_HH_