// For Discord channel
// This Wokwi project: https://wokwi.com/projects/405344188326256641

// Serial1 for Wokwi, Serial for real life
#define __SERIAL Serial1

#define NUM_SAMPLES 100

// The leftIndex and rightIndex point to the first free element.
int leftIndex = 0;
int rightIndex = 0;               

// Always use "unsigned long" when dealing with millis().
unsigned long leftList[NUM_SAMPLES];
unsigned long rightList[NUM_SAMPLES];

// Variables for the millis timer.
unsigned long previousMillis;
const unsigned long interval = 5000;

void setup() 
{
  __SERIAL.begin(115200);
  __SERIAL.println("Hello, Raspberry Pi Pico!");

  // Initialize the indexes.
  leftIndex = 0;
  rightIndex = 0;
  
  // Give Right a head start
  addRight(millis());
}

void loop() 
{
  unsigned long currentMillis = millis();

  // When this is run the first time, millis might still be zero
  addRight(millis());

  addLeft(millis());

  // -----------------------------------------------
  // millis timer
  // -----------------------------------------------
  if(currentMillis - previousMillis >= interval)
  {
    previousMillis = currentMillis;

    printIt();

    addLeft(millis()); // extra sample to left list
  }

  delay(1000); // slow down the sketch
}

void addLeft(unsigned long sample)
{
  if(leftIndex >= NUM_SAMPLES)
  {
    __SERIAL.println("Left is full");
  }
  else
  {
    __SERIAL.print("Add Left,  ");
    leftList[leftIndex++] = sample;
  }
}

void addRight(unsigned long sample)
{
  if(rightIndex >= NUM_SAMPLES)
  {
    __SERIAL.println("Right is full");
  }
  else
  {
    __SERIAL.print("Add Right,  ");
    rightList[rightIndex++] = sample;
  }
}

void printIt()
{
  __SERIAL.println();
  __SERIAL.println("--------------------------------");
  __SERIAL.print("leftIndex = ");
  __SERIAL.print(leftIndex);
  __SERIAL.print(", rightIndex = ");
  __SERIAL.print(rightIndex);
  __SERIAL.println();

  __SERIAL.print("(L,R)=");

  int both = min(leftIndex, rightIndex);
  for(int i=0; i<both; i++)
  {
    __SERIAL.print("(");
    __SERIAL.print(leftList[i]);
    __SERIAL.print(",");
    __SERIAL.print(rightList[i]);
    __SERIAL.print("),");
  }

  if(leftIndex == rightIndex)
  {
    __SERIAL.println();
    __SERIAL.print("There is no remaining data.");
  }
  else if(leftIndex > rightIndex)
  {
    __SERIAL.println();
    __SERIAL.print("RemainingLeft=");
    for(int i=both; i<leftIndex; i++)
    {
      __SERIAL.print(leftList[i]);
      __SERIAL.print(",");
    }
  }
  else        // the rightIndex is higher than the leftIndex
  {
    __SERIAL.println();
    __SERIAL.print("RemainingRight=");
    for(int i=both; i<rightIndex; i++)
    {
      __SERIAL.print(rightList[i]);
      __SERIAL.print(",");
    }
  }

  __SERIAL.println();
  __SERIAL.println("--------------------------------");
}