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

#define SCREEN_WIDTH 128  // OLED display width
#define SCREEN_HEIGHT 64  // OLED display height

#define DHTPIN 15   // Pino do sensor DHT11
#define DHTTYPE DHT11  // Tipo do sensor DHT11

#define POT_PIN 34   // Pino do potenciômetro
#define RELAY_NO_PIN 19  // Pino do relé NO
#define RELAY_NC_PIN 18  // Pino do relé NC
#define BUZZER_PIN 25   // Pino do buzzer

#define BATTERY_ICON_WIDTH 6
#define BATTERY_ICON_HEIGHT 12
#define BATTERY_PIN 35  // Pino para leitura da tensão da bateria
#define VOLTAGE_MAX 3.3  // Tensão máxima da bateria (3.3V para ESP32)
#define VOLTAGE_MIN 3.0  // Tensão mínima da bateria
#define LOW_BATTERY_LEVEL 20  // Nível de bateria considerado baixo

#define SCL_PIN 22   // Pino SCL
#define SDA_PIN 21  // Pino SDA

DHT dht(DHTPIN, DHTTYPE);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

const int numReadings = 10;
float readings[numReadings];
int idx = 0;
float total = 0;
float averageTemp = 0;

float readBatteryVoltage() {
  int rawValue = analogRead(BATTERY_PIN);
  float voltage = rawValue * (VOLTAGE_MAX / 4095.0);  // Ajuste para 3.3V
  voltage = voltage * 2.0;  // Considerando o divisor de tensão 10kΩ e 10kΩ
  return voltage;
}

int calculateBatteryLevel(float voltage) {
  int level = map(voltage, VOLTAGE_MIN, VOLTAGE_MAX, 0, 100);
  return constrain(level, 0, 100);
}

void drawBatteryIcon(int x, int y, int width, int height, int batteryLevel) {
  int batteryFill = map(batteryLevel, 0, 100, height - 2, 2);
  
  display.drawRect(x, y, width, height, WHITE);
  
  display.fillRect(x + 1, y + height - batteryFill, width - 2, batteryFill, WHITE);

  if (batteryLevel <= LOW_BATTERY_LEVEL) {
    display.fillRect(x + 1, y + height - batteryFill, width - 2, batteryFill, BLACK);
    display.drawRect(x, y, width, height, WHITE);
  }
}

void setup() {
  Wire.begin();
  Serial.begin(9600);
  
  pinMode(RELAY_NO_PIN, OUTPUT);
  pinMode(RELAY_NC_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  dht.begin();
  
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.clearDisplay();
  display.setTextSize(1.8);
  display.setTextColor(WHITE);
  
  int16_t x = (SCREEN_WIDTH - display.getCursorX()) / 2;
  
  display.setCursor(35, 10);
  display.println("Eletronica");
  display.setCursor(38, 25);
  display.println("Bem-vindo");
  display.setCursor(32, 40);
  display.println("Etec - 2024");
  display.display();
  delay(4000);
}

void loop() {
  static int batteryLevel = 100;
  batteryLevel -= 1;

  float humidity = dht.readHumidity();
  
  total = total - readings[idx];
  readings[idx] = dht.readTemperature();
  total = total + readings[idx];
  idx = (idx + 1) % numReadings;
  averageTemp = total / numReadings;

  int potValue = analogRead(POT_PIN);
  float tempRef = map(potValue, 0, 4095, -40, 40);

  if (isnan(averageTemp) || isnan(humidity)) {
    Serial.println("Erro ao ler o sensor DHT11!");
    return;
  }

  if (averageTemp >= tempRef) {
    digitalWrite(RELAY_NO_PIN, HIGH);
    digitalWrite(RELAY_NC_PIN, LOW);
    tone(BUZZER_PIN, 660);
  } else {
    digitalWrite(RELAY_NO_PIN, LOW);
    digitalWrite(RELAY_NC_PIN, HIGH);
    noTone(BUZZER_PIN);
  }

  float voltage = readBatteryVoltage();
  Serial.print("Tensão da bateria: ");
  Serial.println(voltage);
  
  batteryLevel = calculateBatteryLevel(voltage);

  display.clearDisplay();
  
  display.setTextSize(0.5);
  display.setCursor(SCREEN_WIDTH - BATTERY_ICON_WIDTH - 15, 5);
  display.print(batteryLevel);
  display.print("%");
  
  drawBatteryIcon(SCREEN_WIDTH - BATTERY_ICON_WIDTH - 2, 2, BATTERY_ICON_WIDTH, BATTERY_ICON_HEIGHT, batteryLevel);
  
  display.setTextSize(1);
  display.setCursor(0, 18);
  display.print("Temp. Ref.: ");
  display.print(tempRef);
  display.println(" C");
  display.print("Temp. Atual: ");
  display.print(averageTemp);
  display.println(" C");
  display.print("Umidade: ");
  display.print(humidity);
  display.println(" %");
  display.display();

  Wire.beginTransmission(0);
  if (Wire.endTransmission() == 0) {
    Serial.println("I2C device found!");
  } else {
    Serial.println("I2C device not found!");
  }

  delay(2000);
}