#include <Wire.h>
#include <Adafruit_SSD1306.h>

#define ANALOG_IN_PIN A0

const float maxVoltage = 28.8;
const float minVoltage = 23.9;

float adc_voltage = 0.0;
float in_voltage = 0.0;
float R1 = 30000.0 + 412912.91;
float R2 = 7500.0;
float ref_voltage = 5.0;

int adc_value = 0;

Adafruit_SSD1306 display(128, 64, &Wire, -1);

class RGBLed {
  public:
    RGBLed(int redPin, int greenPin, int bluePin) :
      _redpin(redPin), _greenpin(greenPin), _bluepin(bluePin) {}

    void write(float red, float green, float blue) {
      float mappedRed = map(red, 0.0, 1.0, 0.0, 0.39);
      float mappedGreen = map(green, 0.0, 1.0, 0.7, 1.0);
      float mappedBlue = map(blue, 0.0, 1.0, 0.4, 0.69);

      analogWrite(_redpin, mappedRed * 255);
      analogWrite(_greenpin, mappedGreen * 255);
      analogWrite(_bluepin, mappedBlue * 255);
    }

  private:
    int _redpin;
    int _greenpin;
    int _bluepin;
};

RGBLed myRGBled(9, 10, 11);

void setup() {
  Serial.begin(9600);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.println("Voltage:");
  display.display();
}

void loop() {
  adc_value = analogRead(ANALOG_IN_PIN);
  adc_voltage = (adc_value * ref_voltage) / 1023.0;
  in_voltage = adc_voltage / (R2 / (R1 + R2));

  float percentage = map(in_voltage, minVoltage, maxVoltage, 0, 100);

  if (percentage >= 70) {
    myRGBled.write(0.0, 1.0, 0.0); // Green
  } else if (percentage >= 40) {
    myRGBled.write(1.0, 1.0, 0.0); // Yellow
  } else if (percentage >= 10) {
    myRGBled.write(1.0, 0.0, 0.0); // Red
  } else {
    for (int i = 0; i < 5; i++) {
      myRGBled.write(1.0, 0.0, 0.0); // Blinking red
      delay(500);
      myRGBled.write(0.0, 0.0, 0.0);
      delay(500);
    }
  }

  display.setCursor(0, 10);
  display.println(in_voltage, 2);
  display.display();

  display.setTextSize(0.5);
  display.setTextColor(WHITE);
  display.setCursor(100, 0);
  display.print(percentage, 1);
  display.print("%");
  display.display();

  delay(1000);
}