#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <DHT.h>

// ===== DHT22 =====
#define DHTPIN 2
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// ===== LCD =====
LiquidCrystal_I2C lcd(0x27, 16, 2);

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

void setup() {
  Serial.begin(9600);

  dht.begin();

  lcd.init();
  lcd.backlight();

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED not found");
    while (true);
  }

  lcd.setCursor(0, 0);
  lcd.print("welcome to");
  lcd.setCursor(0, 1);
  lcd.print("whether System");
  delay(3000);
  lcd.clear();
}

void loop() {

  float temp = dht.readTemperature();
  float hum  = dht.readHumidity();

  if (isnan(temp) || isnan(hum)) {
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error   ");
    return;
  }

  // ===== LCD ROW 0 (Temp + Humidity) =====
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temp);
  lcd.print("C ");

  lcd.print("H:");
  lcd.print(hum);
  lcd.print("% ");

  // ===== OLED =====
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);

  display.setCursor(0, 0);
  display.println("Smart Advice:");

  // ===== CONDITIONS =====
  if (temp > 35) {
    lcd.setCursor(0, 1);
    lcd.print("VERY HOT!     ");

    display.setCursor(0, 20);
    display.println("Use Umbrella!");
  }
  else if (temp >= 15 && temp <= 25) {
    lcd.setCursor(0, 1);
    lcd.print("NORMAL TEMP   ");

    display.setCursor(0, 20);
    display.println("Use Sunscreen!");
  }
  else if (temp < 5) {
    lcd.setCursor(0, 1);
    lcd.print("VERY COLD!    ");

    display.setCursor(0, 20);
    display.println("Wear Jackets!");
  }
  else {
    lcd.setCursor(0, 1);
    lcd.print("MODERATE      ");

    display.setCursor(0, 20);
    display.println("Stay Comfort!");
  }

  display.display();

  delay(2000);
}