#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <RTClib.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>

#define TFT_CS 15 
#define TFT_DC 2
#define TFT_RST -1
#define SD_CS 5  // Chip select pin for the microSD card module
#define DHTPIN 4 // Pin which is connected to the DHT22
#define DHTTYPE DHT22 // DHT 22 (AM2302)

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
RTC_DS1307 rtc;
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  Serial.println("Initializing ILI9341 display, RTC module, SD card, and DHT22 sensor...");

  // Initialize the ILI9341 display
  tft.begin();
  tft.setRotation(0);  // Rotate the display 180 degrees
  tft.fillScreen(ILI9341_BLACK);

  // Initialize I2C for RTC
  Wire.begin(21, 22);  // SDA on GPIO 21, SCL on GPIO 22

  // Initialize the RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is NOT running, let's set the time!");
    // Set the time to the date & time this sketch was compiled
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // Initialize the SD card
  if (!SD.begin(SD_CS)) {
    Serial.println("Initialization failed!");
    tft.setCursor(0, 0);
    tft.setTextColor(ILI9341_RED);
    tft.setTextSize(2);
    tft.println("SD init failed!");
    while (1);
  }
  Serial.println("SD card initialized.");

  // Create or open the CSV file and write the header
  File dataFile = SD.open("/datalog.csv", FILE_WRITE);
  if (dataFile) {
    if (dataFile.size() == 0) {  // Check if file is empty to write the header
      dataFile.println("Date,Time,Temperature,Humidity");  // Write the CSV header
    }
    dataFile.close();
  } else {
    Serial.println("Error opening datalog.csv");
  }

  // Initialize the DHT22 sensor
  dht.begin();

  // Initial display of time and date
  displayTime();
}

void loop() {
  displayTime();
  delay(1000);  // Update the time every second
}

void displayTime() {
  DateTime now = rtc.now();

  // Read temperature and humidity from DHT22
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Check if any reads failed and exit early (to try again).
  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Display the current time
  tft.setCursor(0, 0);
  tft.setTextColor(ILI9341_WHITE, ILI9341_BLACK);  // Draw white text on black background to overwrite previous time
  tft.setTextSize(2);
  tft.printf("Time: %02d:%02d:%02d", now.hour(), now.minute(), now.second());

  // Display the current date
  tft.setCursor(0, 20);
  tft.setTextColor(ILI9341_YELLOW, ILI9341_BLACK);  // Draw yellow text on black background to overwrite previous date
  tft.setTextSize(2);
  tft.printf("Date: %02d/%02d/%d", now.day(), now.month(), now.year());

  // Display the temperature
  tft.setCursor(0, 40);
  tft.setTextColor(ILI9341_CYAN, ILI9341_BLACK);
  tft.setTextSize(2);
  tft.printf("Temp: %.1fC", temperature);

  // Display the humidity
  tft.setCursor(0, 60);
  tft.setTextColor(ILI9341_GREEN, ILI9341_BLACK);
  tft.setTextSize(2);
  tft.printf("Humidity: %.1f%%", humidity);

  // Log the time, date, temperature, and humidity to the CSV file
  logToCSV(now, temperature, humidity);
}

void logToCSV(DateTime now, float temperature, float humidity) {
  File dataFile = SD.open("/datalog.csv", FILE_WRITE);
  if (dataFile) {
    dataFile.printf("%02d/%02d/%d,%02d:%02d:%02d,%.1f,%.1f\n",
                    now.day(), now.month(), now.year(),
                    now.hour(), now.minute(), now.second(),
                    temperature, humidity);
    dataFile.close();
    Serial.println("Data logged to CSV.");
  } else {
    Serial.println("Error opening datalog.csv for writing.");
  }
}