#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <RTClib.h>
#include <OneWire.h>
#include <DallasTemperature.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL)   
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Pin definitions
const int AirTemp = 25; // Digital pin connected to the DHT sensor
const int CircPump = 2; // Digital pin Circulation Pump
const int TankAir = 4; // Digital pin Tank Air
const int TankLights = 5; // Digital pin Tank Lights
const int WaterTemp = 26; // Digital pin for DS18B20 temperature sensor

// Define Sensors
#define DHTTYPE DHT22
DHT dhtTemperature(AirTemp, DHTTYPE);

// OneWire and Dallas Temperature instances for DS18B20
OneWire oneWire(WaterTemp);
DallasTemperature waterTempSensor(&oneWire);

// RTC instance
RTC_DS3231 rtc;

// Global variables
unsigned long startTime = 0;
boolean lightState = false;
boolean fanState = false;
unsigned long fanStartTime = 0; // Variable to track fan start time
bool pumpState = false;
unsigned long lastPumpTime = 0;

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

  dhtTemperature.begin();
  waterTempSensor.begin(); // Initialize the DS18B20 sensor

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  delay(2000);
  display.clearDisplay();
  display.setTextColor(WHITE);

  // Initialize Pins
  pinMode(CircPump, OUTPUT);
  pinMode(TankAir, OUTPUT);
  pinMode(TankLights, OUTPUT);

  // Initialize the RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1) {} // Halt if RTC not found
  }
  //rtc.adjust(DateTime(2024, 11, 10, 19, 55, 0)); // uncomment and set time, comment out after initial load and reload to keep time

}

void loop() {
  delay(5000);

  // Read temperature and humidity from DHT22
  float tf = dhtTemperature.readTemperature();
  int hf = dhtTemperature.readHumidity(); // Convert humidity to int

  // Convert temperature to Fahrenheit
  float ff = tf * 1.8 + 32;

  if (isnan(ff) || isnan(tf) || isnan(hf)) {
    Serial.println("Failed to read from DHT22 sensor!");
  }

  // Read water temperature from DS18B20
  waterTempSensor.requestTemperatures();
  float waterTempC = waterTempSensor.getTempCByIndex(0);
  float waterTempF = waterTempC * 9.0 / 5.0 + 32.0;

  if (isnan(waterTempC)) {
    Serial.println("Failed to read from DS18B20 sensor!");
  }

  // Get current time
  DateTime now = rtc.now();

  unsigned long currentTime = millis();

  // Circulation Pump - Run 30 Minutes every 4 hours
  if (!pumpState && (currentTime - lastPumpTime) >= 14400000) {
    digitalWrite(CircPump, HIGH);
    pumpState = true;
    lastPumpTime = currentTime;
  }

  if (pumpState && (currentTime - lastPumpTime) >= 1800000) {
    digitalWrite(CircPump, LOW);
    pumpState = false;
  }

  // Control lights based on time
  if (now.hour() >= 6 && now.hour() < 18) {
    digitalWrite(TankLights, HIGH);
    startTime = millis(); // Record the start time
    lightState = true;
  } else {
    digitalWrite(TankLights, LOW);
    lightState = false;
  }

  // Clear display
  display.clearDisplay();

  // Display "Grow UP!!" and Time
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.print("Grow UP!");

  display.setCursor(67, 0);
  display.print(now.hour() % 12);
  display.print(":");
  display.print(now.minute() < 10 ? "0" : ""); // Print "0" if minutes are less than 10
  display.print(now.minute(), DEC);
  display.print(now.hour() >= 12 ? " PM" : " AM");

  // Display Air Temperature
  display.setTextSize(1);
  display.setCursor(0, 16);
  display.print("Air   T: ");
  display.setTextSize(1);
  display.setCursor(50, 16);
  display.print(int(ff));
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(1);
  display.print("F");

  // Display Humidity
  display.setTextSize(1);
  display.setCursor(85, 16);
  display.print("H:  ");
  display.setTextSize(1);
  display.setCursor(100, 16);
  display.print(hf);
  display.print("%");

  // Display Water Temperature
  display.setTextSize(1);
  display.setCursor(0, 36); 
  display.print("Water T: ");
  display.setTextSize(1);
  display.setCursor(50, 36);
  display.print(int(waterTempF));
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(1);
  display.print("F");

  display.display();

  // Print temperatures and humidity to serial monitor
  Serial.print("Air Temperature: ");
  Serial.print(int(ff)); // Print temperature without decimals
  Serial.println(" F");
  Serial.print("Humidity: ");
  Serial.print(hf);
  Serial.println(" %");
  Serial.print("Water Temperature: ");
  Serial.print(waterTempF);
  Serial.println(" F");
}