/**
   Arduino Electronic-Dreno (I2C) - v1.2
   Correção do display "vazio" pós-drenagem e unidade NTU.
*/

#include <Wire.h> 
#include <LiquidCrystal_I2C.h> 

#define BUZZER_PIN 8
#define RELAY_PIN 9           
#define TURBIDITY_PIN A0      
const int pinoPot = A1;       
const int pinoLED = 3;        

#define DRAIN_DURATION 10000        
unsigned long DRAIN_INTERVAL = 60000; 
float TURBIDITY_THRESHOLD = 2.5;    

unsigned long lastDrainTime = 0;
unsigned long lastInteractionTime = 0;
const unsigned long DISPLAY_TIMEOUT = 30000; 
bool displayIsOn = true;
float lastTurbidityValue = -1.0; 

LiquidCrystal_I2C lcd(0x27, 16, 2); 

void wakeUpDisplay() {
  lastInteractionTime = millis();
  if (!displayIsOn) {
    lcd.backlight();
    displayIsOn = true;
    lastTurbidityValue = -1.0; 
  }
}

void playTone(int freq, int duration) {
  tone(BUZZER_PIN, freq, duration);
  delay(duration);
}

float readTurbidity() {
  int sensorValue = analogRead(TURBIDITY_PIN);
  return (float)sensorValue / 1024.0 * 5.0;
}

void executeDrain(String motivo) {
  wakeUpDisplay();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("DRENO ATIVADO!");
  lcd.setCursor(0, 1);
  lcd.print(motivo);
  
  playTone(1500, 200);
  playTone(1200, 200);

  digitalWrite(RELAY_PIN, HIGH);
  digitalWrite(pinoLED, HIGH);
  for (int i = 0; i < 10; i++) {
    delay(DRAIN_DURATION / 10);
    lcd.setCursor(i + 3, 1);
    lcd.print(">");
  }
  digitalWrite(RELAY_PIN, LOW);
  
  playTone(1000, 500);
  lastDrainTime = millis();
  lastTurbidityValue = -1.0; // Força o loop() a redesenhar a tela de monitoramento
}
 
void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(TURBIDITY_PIN, INPUT);
  pinMode(pinoLED, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);
  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("ELETRONIC-DRENO");
  delay(2000);
  lcd.clear();
}

void loop() {
  unsigned long currentTime = millis();
  float currentTurbidity = readTurbidity();

  // Controle de brilho do LED indicador
  int valorPot = analogRead(pinoPot);
  analogWrite(pinoLED, map(valorPot, 0, 1023, 0, 255));

  // Cálculo NTU
  float NTU = -1120.4 * (currentTurbidity * currentTurbidity) + 5742.3 * currentTurbidity - 4353.8;
  if(NTU < 0) NTU = 0; // Evita valores negativos no display

   // 1. Atualização do Display
  if (displayIsOn) {
    if (abs(currentTurbidity - lastTurbidityValue) > 0.05) {
      lcd.setCursor(0, 0);
      lcd.print("Turbidez:");
      lcd.print((int)NTU); // Exibe como inteiro para facilitar leitura
      lcd.print("NTU    "); 
      
      lcd.setCursor(0, 1);
      if (currentTurbidity >= TURBIDITY_THRESHOLD) {
        lcd.print("Status: SUJA    ");
      } else {
        lcd.print("Status: MONITOR ");
      }
      lastTurbidityValue = currentTurbidity;
    }
  }

  // 2. Lógica de Acionamento
  if (currentTurbidity > TURBIDITY_THRESHOLD) {
    executeDrain("POR TURBIDEZ   ");
  } 
  else if (currentTime - lastDrainTime >= DRAIN_INTERVAL) {
    executeDrain("POR TEMPO      ");
  }

  // 3. Standby do Display
  if (displayIsOn && (currentTime - lastInteractionTime > DISPLAY_TIMEOUT)) {
    lcd.noBacklight();
    displayIsOn = false;
  }
  
  delay(200); 
}