#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP280.h>
#include <DHT.h>
#include <LiquidCrystal.h>
#include <SPI.h>
#include <SD.h>  // Include the SD library

#define BMP_SCK  (13)
#define BMP_MISO (12)
#define BMP_MOSI (11)
#define BMP_CS   (10)
#define DHTPIN 7       
#define DHTTYPE DHT22  
#define BUTTON_PIN 6  
#define SD_CS_PIN 10   // SD card CS pin

DHT dht(DHTPIN, DHTTYPE);
Adafruit_BMP280 bmp;

int RS = 12, E = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(RS, E, d4, d5, d6, d7);

int buttonState = 0;      
int lastButtonState = 0;  
int screen = -1; 

File dataFile;

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  lcd.begin(16, 2);  
  dht.begin();
  bmp.begin();
  Serial.begin(9600);
  
  lcd.print("Weather Station");
  delay(2000);
  lcd.clear();

  bmp.setSampling(Adafruit_BMP280::MODE_NORMAL,     
                  Adafruit_BMP280::SAMPLING_X2,     
                  Adafruit_BMP280::SAMPLING_X16,    
                  Adafruit_BMP280::FILTER_X16,      
                  Adafruit_BMP280::STANDBY_MS_500);

  // Initialize the SD card
  if (!SD.begin(SD_CS_PIN)) {
    lcd.print("SD Init Failed");
    while (1);
  }
  lcd.print("SD Card Ready");
  delay(2000);
  lcd.clear();
}

void loop() {
  buttonState = digitalRead(BUTTON_PIN);

  if (buttonState == HIGH && lastButtonState == LOW) {
    screen = (screen + 1) % 4;  
    updateScreen(screen);
  }

  lastButtonState = buttonState;

  float temp = dht.readTemperature();
  float humi = dht.readHumidity();
  float pressure = bmp.readPressure() / 100.0;

  if (!isnan(humi) && !isnan(temp) && !isnan(pressure)) {
    logData(temp, humi, pressure);  // Call function to log data
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error!");
  }

  delay(1000);  
}

void updateScreen(int screen) {
  lcd.clear();
  lcd.setCursor(15, 1);
  lcd.print(String(screen + 1));
  lcd.setCursor(2, 0);

  if (screen == 0) {
    float temp = dht.readTemperature();
    lcd.print("Temperature: ");
    lcd.setCursor(3, 1);
    lcd.print(temp);
    lcd.print(" C");
  } else if (screen == 1) {
    float humi = dht.readHumidity();
    lcd.print("Humidity: ");
    lcd.setCursor(3, 1);
    lcd.print(humi);
    lcd.print(" %");
  } else if (screen == 2) {
    float pressure = bmp.readPressure() / 100.0; 
    lcd.setCursor(2, 0);
    lcd.print("Pressure: ");
    lcd.setCursor(3, 1);
    lcd.print(pressure);
    lcd.print(" hPa");
  } else {
    lcd.setCursor(2, 0);
    lcd.print("Thank you !");
  }
}

// Function to log data to SD card
void logData(float temperature, float humidity, float pressure) {
  // Open file in append mode
  dataFile = SD.open("weather.txt", FILE_WRITE);
  
  if (dataFile) {
    // Write data in CSV format: temperature, humidity, pressure
    dataFile.print("Temperature: ");
    dataFile.print(temperature);
    dataFile.print(" C, Humidity: ");
    dataFile.print(humidity);
    dataFile.print(" %, Pressure: ");
    dataFile.print(pressure);
    dataFile.println(" hPa");

    dataFile.close();  // Close the file
    Serial.println("Data logged to SD.");
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Error Writing SD");
  }
}