/*
   WOKWi test proj.: Raspberry Pi Pico C/C++ SDK (Project WITH CMakelist)
   Author: Sergio A. González
   For More Info Visit: https://icyte.conicet.gov.ar/investigadores
*/

#include <stdio.h>
#include "pico/stdlib.h"
#include <stdlib.h>
#include <math.h>
#include <time.h>

#define BUILTIN_LED PICO_DEFAULT_LED_PIN
#define WINDOW_SIZE 4096

#if ( defined(__GNUC__) || defined(__GNUG__) )
// GCC version in a string
char versionStringGCC[16];
#endif

typedef struct {
    float *buffer;
    uint16_t size;
    uint16_t index;
    float sum;
} RunningAverage_t;

// Function to initialize the RunningAverage struct
RunningAverage_t* createRunningAverage(int size) {
    RunningAverage_t *ra = (RunningAverage_t*)malloc(sizeof(RunningAverage_t));
    if (ra == NULL) {
        return NULL; // Memory allocation failed
    }
    ra->buffer = (float*)malloc(size * sizeof(float));
    if (ra->buffer == NULL) {
        free(ra);
        return NULL; // Memory allocation failed
    }
    ra->size = size;
    ra->index = 0;
    ra->sum = 0.0f;
    for (int i = 0; i < size; i++) {
        ra->buffer[i] = 0.0f;
    }
    return ra;
}

// Function to add a new value to the running average
void addValue(RunningAverage_t *ra, float newValue) {
    ra->sum -= ra->buffer[ra->index];
    ra->buffer[ra->index] = newValue;
    ra->sum += newValue;
    ra->index = (ra->index + 1) % ra->size;
}

// Function to get the current running average
float getAverage(RunningAverage_t *ra) {
    return ra->sum / ra->size;
}

// Function to free the allocated memory
void freeRunningAverage(RunningAverage_t *ra) {
    free(ra->buffer);
    free(ra);
}

int main() {
  uint16_t bufferSize = WINDOW_SIZE;
  float data = 0.0f;
  uint64_t i = 0;
   
  RunningAverage_t *myRunningAverage = createRunningAverage(bufferSize);

  stdio_init_all();

  // Seed the random number generator once at the start of the program
  srand(time(NULL));

  // Format the version number into a string
	snprintf(versionStringGCC, sizeof(versionStringGCC), "%d.%d.%d", __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__);
  /* Note: Last time I checked this was 14.2.0, being on the bleeding 
   * edge is certainly not a good thing regarding your C compiler.
   */

  gpio_init(BUILTIN_LED);
  gpio_set_dir(BUILTIN_LED, GPIO_OUT);

  printf("Hello World From Pi Pico - Using USB CDC!:\n");
  printf("GCC ver. in WOKWi: %s\n",  versionStringGCC);
  printf("Max rand Gen with this toolchain is: %d\n", RAND_MAX);

  while (1)
  {
    gpio_put(BUILTIN_LED, 1);
    sleep_ms(50);

    data = rand();  // random never generated is an 'integer' stored as 'float'
    printf("Random number (0 to RAND_MAX): %d\n", (int)data);
    // we run the average on the saved float number
    addValue(myRunningAverage, data);
    printf("Running Average: %f\n", getAverage(myRunningAverage));
    /* The moving average of a time series is not a measure of randomness quality but 
     * it can certainly highlight longer-term trends or cycles in a time series. 
     * it can help in identifying patterns that might indicate a lack of
     * randomness (like trends or cycles).
     * Use 'serial plotter' in WOKWi to see this.
     */
    gpio_put(BUILTIN_LED, 0);
    sleep_ms(100);
    i++;
  }
}