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

#define LED_PIN 15 
#define TRIG_PIN 18
#define ECHO_PIN 19

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

DHT dht22(14, DHT22); // Ensure you are using the correct DHT sensor type

double fnc_ultrasonic_distance(int trigPin, int echoPin) {
  unsigned long duration;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH, 18000);
  Serial.print("Echo Duration: ");
  Serial.println(duration);
  if (duration == 0) return 999.0;
  return (duration / 58.0); // Convert to cm
}

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(32, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(4, INPUT);
  pinMode(18, OUTPUT);
  pinMode(14, INPUT);
  pinMode(12, OUTPUT);
  pinMode(15, OUTPUT);
  pinMode(33, INPUT);

  Serial.begin(115200);
  Serial.flush();
  while (Serial.available() > 0) Serial.read();

  dht22.begin(); // Ensure the sensor is properly initialized

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

  display.display();
  delay(2000);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  Serial.println("Setup complete");
}

void loop() {
  Serial.println("Loop iteration");

  yield();

  // Read sensor data
  double temperature = dht22.readTemperature();
  double humidity = dht22.readHumidity();

  // Debug statements to check the sensor readings
  Serial.print("Temperature: ");
  Serial.println(temperature);
  Serial.print("Humidity: ");
  Serial.println(humidity);

  // Check if the readings are valid
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Display temperature and humidity on separate lines
  String line1 = "Temp: " + String(temperature, 1) + "C";
  String line2 = "Humidity: " + String(humidity, 1) + "%";
  String line3;

  // Control the LED based on light sensor reading
  if (analogRead(35) > 700) {
    digitalWrite(32, HIGH); // Turn on LED when there is no light
    line3 = "LED: ON";
  } else {
    digitalWrite(32, LOW);
    line3 = "LED: OFF";
  }

  // Measure water level using ultrasonic sensor
  double distance = fnc_ultrasonic_distance(TRIG_PIN, ECHO_PIN);
  Serial.print("Distance: ");
  Serial.println(distance);

  // Assuming a maximum distance of 400 cm (tank empty) and minimum distance of 0 cm (tank full)
  int waterLevel = map(distance, 0, 400, 100, 0); // Map distance to percentage
  waterLevel = constrain(waterLevel, 0, 100); // Ensure water level is between 0 and 100
  String line4 = "Water Level: " + String(waterLevel) + "%";

  // Display all information on the OLED
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print(line1);
  display.setCursor(0, 10);
  display.print(line2);
  display.setCursor(0, 20);
  display.print(line3);
  display.setCursor(0, 30);
  display.print(line4);

  display.display();
  delay(1000);
}