#include "SensorHistory.h"

#include <Arduino.h>

//static const char *TAG = "SensorHistory";

SensorHistory::SensorHistory(const int size) {
  _size = size;
  _values = (float*) malloc(_size * sizeof(float));
  clear();
}

SensorHistory::~SensorHistory()
{
  if (_values != NULL) free(_values);
}

void SensorHistory::clear(void) {
  _index = 0;
  _cnt = 0;
  for (int i = 0; i < _size; i++)
  {
    _values[i] = 0.0; // keeps addValue simpler
  }
}

void SensorHistory::addValue(const float value) {
  if (_values == NULL) return;

  _values[_index] = value;
  _index = (_index+1) % _size;

  if (_cnt < _size) _cnt++;
}

float SensorHistory::getAverage(void) const {
  if (_cnt == 0) return NAN;
  float sum = 0;
  for (int i = 0; i < _cnt; i++) {
    sum += _values[i];
  }
  return sum / _cnt;

}

float SensorHistory::getMin(void) const {
  if (_cnt == 0) return NAN;
  float min = _values[0];
  for (int i = 0; i < _cnt; i++) {
    if (_values[i] < min) min = _values[i];
  }
  return min;
}

float SensorHistory::getMax(void) const {
  if (_cnt == 0) return NAN;
  float max = _values[0];
  for (int i = 0; i < _cnt; i++) {
    if (_values[i] > max) max = _values[i];
  }
  return max;
}

float SensorHistory::getElement(int index) const {
  if (_cnt == 0) return NAN;
  index = (_index-1 - index) % _size;
  if (index < 0) index = _size+index;
  if (index >= _cnt) return NAN;

  return _values[index];
}

float SensorHistory::getFirst(void) const {
  if (_cnt < _size) return _values[0];
  return getElement(-1);
  
}