/*
Serial interface example
By GllBhh for Fab Academy 2023
Based on AlexGyver example, but without any external libraries
https://github.com/AlexGyver/tutorials/tree/master/parsing/parseSerial
*/

#define LED 0
#define BTN 1

int buttonState;  //this variable tracks the state of the button, HIGH if not pressed, LOW if pressed
int lastButtonState = LOW;  //this variable tracks the last state of the button, HIGH if not pressed, LOW if pressed
unsigned long tmr1;      //global timer to track last button event
int debounce = 50;       // debounce delay to avoid false readings from button

void setup() {
  Serial.begin(9600);
  pinMode(LED, OUTPUT);
  pinMode(BTN, INPUT_PULLUP);
}



/*from Arduino to PC
  0,1 - Buttun press
*/


/*From PC to Arduino
  0,(0..1) - LED on pin 0, where 0 - LED off, 1 - LED on
*/


void loop() {

  //digital Button debounce from 'Debounce' example
  // read the state of a Button into a local variable:
  int reading = digitalRead(BTN);
  // check to see if you just pressed the button
  // (i.e. the input went from LOW to HIGH), and you've waited long enough
  // since the last press to ignore any noise:

  // If the switch changed, due to noise or pressing:
  if (reading != lastButtonState) {
    //update timer when button pin changes state
    tmr1 = millis();
  }
  if ((millis() - tmr1) > debounce) {
    // whatever the reading is at, it's been there for longer than the debounce
    // delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      //update button state
      buttonState = reading;

      // only if the new button state is LOW
      if (buttonState == LOW) {
        Serial.println("0,1");
      }
    }
  }
  //update last button state
  lastButtonState = reading;

  //if there is something is serial buffer
  if (Serial.available()) {
    //we expect data in a format of ints separeted with ',': "key,val1,val2,val3,...,valn\n"
    //\n - new line (println)
    char buf[50];  //array to read from serial
    //get amount of bytes of incoming data
    int amount = Serial.readBytesUntil('\n', buf, 50);
    //close incoming data string by adding a NULL symbol to the end
    buf[amount] = '\0';

    int data[10];        //buffer of ints
    int count = 0;       //counter of ints
    char* offset = buf;  //pointer to a char data type
    //(it holds the memory address of some other variable or array element or parameter or whatever, and in that address is a char)
    //https://www.arduino.cc/reference/en/language/structure/pointer-access-operators/dereference/

    //next part will parse ONLY ints! chars will be parsed as 0
    while (true) {
      data[count++] = atoi(offset);  //write a number to a buffer
      offset = strchr(offset, ',');  //search for next ',' char
      if (offset) offset++;          //if not NULL - continue
      else break;                    //else - leave cycle
    }

    // print buffer
    //for (int i = 0; i < count; i++) Serial.println(data[i]);

    switch (data[0]) {
      case 0:
        //digitalWrite(LED, data[1]);
        analogWrite(LED, data[0]);
        break;
      case 1:
        break;
      case 2:
        break;
    }
  }
}