#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <ESP32Servo.h>

// Pin definitions
#define DHTPIN 4
#define DHTTYPE DHT22
#define SOIL_MOISTURE_PIN 34
#define RELAY_PIN 18
#define LED_PIN 2
#define SERVO_PIN 5

// Soil moisture threshold
const int moistureThreshold = 2000;

// Components
DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo waterPump;

// Wokwi relay module: LOW = relay ON
const int RELAY_ON = LOW;
const int RELAY_OFF = HIGH;

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

  dht.begin();

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

  lcd.setCursor(0, 0);
  lcd.print("Smart Irrigation");
  lcd.setCursor(0, 1);
  lcd.print("System Starting");
  delay(2000);
  lcd.clear();

  waterPump.attach(SERVO_PIN);
  waterPump.write(0);

  pinMode(SOIL_MOISTURE_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

  digitalWrite(RELAY_PIN, RELAY_OFF);
  digitalWrite(LED_PIN, LOW);
}

void startWatering() {
  digitalWrite(RELAY_PIN, RELAY_ON);
  digitalWrite(LED_PIN, HIGH);
  waterPump.write(90);
}

void stopWatering() {
  digitalWrite(RELAY_PIN, RELAY_OFF);
  digitalWrite(LED_PIN, LOW);
  waterPump.write(0);
}

void loop() {
  int soilMoistureValue = analogRead(SOIL_MOISTURE_PIN);
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  bool soilIsDry = soilMoistureValue < moistureThreshold;

  if (soilIsDry) {
    startWatering();
  } else {
    stopWatering();
  }

  // LCD Row 1: Temperature and Humidity
  lcd.setCursor(0, 0);
  lcd.print("                ");
  lcd.setCursor(0, 0);

  if (isnan(temperature) || isnan(humidity)) {
    lcd.print("DHT Error");
  } else {
    lcd.print("T:");
    lcd.print(temperature, 1);
    lcd.print("C H:");
    lcd.print(humidity, 0);
    lcd.print("%");
  }

  // LCD Row 2: Moisture and pump status
  lcd.setCursor(0, 1);
  lcd.print("                ");
  lcd.setCursor(0, 1);

  lcd.print("M:");
  lcd.print(soilMoistureValue);
  lcd.print(" Pump:");

  if (soilIsDry) {
    lcd.print("ON");
  } else {
    lcd.print("OFF");
  }

  // Serial Monitor output
  Serial.print("Soil Moisture: ");
  Serial.print(soilMoistureValue);
  Serial.print(" | Temperature: ");
  Serial.print(temperature);
  Serial.print(" C | Humidity: ");
  Serial.print(humidity);
  Serial.print(" % | Pump: ");
  Serial.println(soilIsDry ? "ON" : "OFF");

  delay(2000);
}