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

#define RED_PIN 5
#define GREEN_PIN 17
#define BLUE_PIN 16

#define TRIG_PIN 4
#define ECHO_PIN 15

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

const int minDistance = 6;
const int maxDistance = 40;

void setup() {

  Serial.begin(115200);

  Wire.begin(18, 19);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(RED_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
  pinMode(BLUE_PIN, OUTPUT);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED nao encontrado!");
    while (true);
  }

  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
}

void loop() {

  int distance = getDistance();

  // Converte distância para porcentagem
  int waterLevel = map(distance, minDistance, maxDistance, 100, 0);

  // Limita entre 0 e 100%
  waterLevel = constrain(waterLevel, 0, 100);

  Serial.print("Distancia: ");
  Serial.print(distance);
  Serial.println(" cm");

  Serial.print("Nivel da agua: ");
  Serial.print(waterLevel);
  Serial.println("%");

  // Mostra no OLED
  displayWaterLevel(waterLevel);

  // Controla LED de acordo com o nível
  controlarLED(waterLevel);

  delay(1000);
}


// =====================================
// MEDIR DISTÂNCIA
// =====================================

int getDistance() {

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000);

  // Se não recebeu retorno
  if (duration == 0) {
    return maxDistance;
  }

  int distance = duration * 0.0343 / 2;

  return distance;
}


// =====================================
// CONTROLAR LED RGB
// =====================================

void controlarLED(int nivel) {

  if (nivel >= 70) {

    // VERDE - tanque cheio
    digitalWrite(RED_PIN, LOW);
    digitalWrite(GREEN_PIN, HIGH);
    digitalWrite(BLUE_PIN, LOW);
  }

  else if (nivel >= 30) {

    // AMARELO - tanque perto de acabar
    digitalWrite(RED_PIN, HIGH);
    digitalWrite(GREEN_PIN, HIGH);
    digitalWrite(BLUE_PIN, LOW);
  }

  else {

    // VERMELHO - pouca água
    digitalWrite(RED_PIN, HIGH);
    digitalWrite(GREEN_PIN, LOW);
    digitalWrite(BLUE_PIN, LOW);
  }
}


// =====================================
// MOSTRAR NÍVEL NO OLED
// =====================================

void displayWaterLevel(int level) {

  display.clearDisplay();

  // Texto "Water"
  display.setCursor(20, 5);
  display.setTextSize(1);
  display.print("Water");

  // Texto "Level"
  display.setCursor(20, 15);
  display.print("Level");

  // Porcentagem
  display.setCursor(0, 30);
  display.setTextSize(3);
  display.print(level);
  display.print("%");


  // =================================
  // TANQUE
  // =================================

  int tankX = 72;
  int tankY = 5;
  int tankWidth = 55;
  int tankHeight = 50;

  // Corpo do tanque
  display.drawRoundRect(
    tankX,
    tankY,
    tankWidth,
    tankHeight,
    5,
    WHITE
  );

  // Tampa
  display.drawLine(
    tankX + 5,
    tankY - 3,
    tankX + tankWidth - 5,
    tankY - 3,
    WHITE
  );

  display.drawLine(
    tankX + 5,
    tankY - 3,
    tankX,
    tankY,
    WHITE
  );

  display.drawLine(
    tankX + tankWidth - 5,
    tankY - 3,
    tankX + tankWidth,
    tankY,
    WHITE
  );

  // Tubo de entrada
  display.drawLine(
    tankX + 8,
    tankY - 6,
    tankX + 8,
    tankY - 12,
    WHITE
  );

  display.drawLine(
    tankX + 8,
    tankY - 12,
    tankX + 14,
    tankY - 12,
    WHITE
  );

  display.drawLine(
    tankX + 14,
    tankY - 12,
    tankX + 14,
    tankY - 6,
    WHITE
  );


  // =================================
  // ÁGUA
  // =================================

  int waterHeight = map(
    level,
    0,
    100,
    0,
    tankHeight
  );

  if (waterHeight > 0) {

    display.fillRect(
      tankX + 2,
      tankY + tankHeight - waterHeight,
      tankWidth - 4,
      waterHeight,
      WHITE
    );
  }

  display.display();
}