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

LiquidCrystal_I2C lcd(0x27, 16, 2);

// ------------------------
// PINAGEM
// ------------------------
#define ENC_CLK 4
#define ENC_DT 5
#define ENC_SW 6

#define MUTE_PIN 10

#define SWITCH_A 11
#define SWITCH_B 12

#define LED1 13
#define LED2 14

// ------------------------
volatile int encoderPos = 50;   // volume inicial
volatile bool encoderMoved = false;
int lastEncoderValue = 50;

// ------------------------
int lastMuteState = HIGH;
bool lastSel = false;

// ------------------------
// ISR do encoder
// ------------------------
void IRAM_ATTR readEncoder() {
  int clk = digitalRead(ENC_CLK);
  int dt  = digitalRead(ENC_DT);

  if (clk == dt) encoderPos++;
  else encoderPos--;

  encoderPos = constrain(encoderPos, 0, 100);
  encoderMoved = true;
}

void setup() {
  Serial.begin(115200);

  // LCD
  Wire.begin(33, 35);
  lcd.init();
  lcd.backlight();

  // Encoder
  pinMode(ENC_CLK, INPUT_PULLUP);
  pinMode(ENC_DT, INPUT_PULLUP);
  pinMode(ENC_SW, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(ENC_CLK), readEncoder, CHANGE);

  // Mute e seletor
  pinMode(MUTE_PIN, INPUT_PULLUP);
  pinMode(SWITCH_A, INPUT_PULLUP);
  pinMode(SWITCH_B, INPUT_PULLUP);

  // LEDs
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);

  // Tela inicial
  lcd.setCursor(0, 0);
  lcd.print("Volume:");
  lcd.setCursor(0, 1);
  lcd.print(encoderPos);
  lcd.print("%");
}

void loop() {
  bool mute = digitalRead(MUTE_PIN) == LOW;

  bool posA = digitalRead(SWITCH_A) == LOW;
  bool posB = digitalRead(SWITCH_B) == LOW;
  bool seletor = posB; // B=fone B / A=fone A

  // ------------------------
  // MUTE
  // ------------------------
  if (mute != lastMuteState) {
    lcd.clear();

    if (mute) {
      lcd.setCursor(0, 0);
      lcd.print("MUTADO");
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, LOW);
    } else {
      lcd.setCursor(0, 0);
      lcd.print("Som ativo");
      delay(1500);

      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Volume:");
      lcd.setCursor(0, 1);
      lcd.print(encoderPos);
      lcd.print("%");
    }

    lastMuteState = mute;
  }

  // ------------------------
  // SELETOR DE FONES
  // ------------------------
  if (seletor != lastSel && !mute) {
    lcd.clear();

    if (seletor) {
      lcd.setCursor(0, 0);
      lcd.print("Fone B");
      Serial.println("Fone B Selecionado");
      digitalWrite(LED1, LOW);
      digitalWrite(LED2, HIGH);
    } else {
      lcd.setCursor(0, 0);
      lcd.print("Fone A");
      Serial.println("Fone A Selecionado");
      digitalWrite(LED1, HIGH);
      digitalWrite(LED2, LOW);
    }

    delay(1500);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Volume:");
    lcd.setCursor(0, 1);
    lcd.print(encoderPos);
    lcd.print("%");

    lastSel = seletor;
  }

  // ------------------------
  // VOLUME — ENCODER ROTATIVO
  // ------------------------
  if (!mute && encoderMoved) {
    encoderMoved = false;

    if (abs(encoderPos - lastEncoderValue) >= 2) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Volume:");
      lcd.setCursor(0, 1);
      lcd.print(encoderPos);
      lcd.print("%");

      lastEncoderValue = encoderPos;
    }
  }

  delay(20);
}