#include <WiFi.h>
#include <PubSubClient.h>
#include <LiquidCrystal_I2C.h>

// WIFI
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ADAFRUIT
#define AIO_SERVER   "io.adafruit.com"
#define AIO_PORT     1883
#define AIO_USERNAME "imen_a"
#define AIO_KEY      "aio_ELhp01ZbLccULgsCRjLfVDo7P8o9"

WiFiClient espClient;
PubSubClient client(espClient);

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

// PINS
#define RELAY_PIN 14
#define SOIL_PIN 32
#define TANK_PIN 33

// FEEDS
String feed_soil;
String feed_tank;
String feed_relay;
String feed_alert;
String feed_weather;

// VARIABLES
bool pumpOn = false;
bool rain = false;

bool alertSoil = false;
bool alertTank = false;
bool alertRain = false;

unsigned long lastSend = 0;

// WIFI
void connectWiFi() {
  lcd.clear();
  lcd.print("WiFi...");

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) delay(300);

  lcd.clear();
  lcd.print("WiFi OK");
  delay(1500);
}

// ALERT
void sendAlert(String msg) {
  Serial.println(msg);
  client.publish(feed_alert.c_str(), msg.c_str());
}

// MQTT CALLBACK (WEATHER)
void callback(char* topic, byte* payload, unsigned int length) {
  String msg = "";
  for (int i = 0; i < length; i++) msg += (char)payload[i];

  if (String(topic) == feed_weather) {

    if (msg == "RAIN") {
      rain = true;
      sendAlert("🌧️ RAIN DETECTED");
    } else {
      rain = false;
      sendAlert("☀️ CLEAR WEATHER");
    }
  }
}

// MQTT
void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32", AIO_USERNAME, AIO_KEY)) {
      client.subscribe(feed_weather.c_str());
      sendAlert("SYSTEM STARTED");
    } else {
      delay(2000);
    }
  }
}

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

  pinMode(RELAY_PIN, OUTPUT);

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

  connectWiFi();

  client.setServer(AIO_SERVER, AIO_PORT);
  client.setCallback(callback);

  // FEEDS
  feed_soil    = String(AIO_USERNAME) + "/feeds/moisture";
  feed_tank    = String(AIO_USERNAME) + "/feeds/tank";
  feed_relay   = String(AIO_USERNAME) + "/feeds/relay";
  feed_alert   = String(AIO_USERNAME) + "/feeds/alert";
  feed_weather = String(AIO_USERNAME) + "/feeds/weather";
}

// LOOP
void loop() {

  if (!client.connected()) reconnect();
  client.loop();

  // READ
  int soil = map(analogRead(SOIL_PIN), 0, 4095, 0, 100);
  int tank = map(analogRead(TANK_PIN), 0, 4095, 0, 100);

  // -------- SMART LOGIC --------
  if (rain) {
    pumpOn = false;

    if (!alertRain) {
      sendAlert("🌧️ RAIN → STOP IRRIGATION");
      alertRain = true;
    }
  }
  else if (tank < 20) {
    pumpOn = false;

    if (!alertTank) {
      sendAlert("⚠️ TANK EMPTY - REFILL");
      alertTank = true;
    }
  }
  else if (soil < 40) {
    pumpOn = true;

    if (!alertSoil) {
      sendAlert("🚨 DRY SOIL → PUMP ON");
      alertSoil = true;
    }
  }
  else {
    pumpOn = false;
    alertSoil = false;
    alertTank = false;
    alertRain = false;
  }

  digitalWrite(RELAY_PIN, pumpOn ? HIGH : LOW);

  // SEND DATA
  if (millis() - lastSend > 5000) {
    lastSend = millis();

    char buf[10];

    sprintf(buf, "%d", soil);
    client.publish(feed_soil.c_str(), buf);

    sprintf(buf, "%d", tank);
    client.publish(feed_tank.c_str(), buf);

    client.publish(feed_relay.c_str(), pumpOn ? "ON" : "OFF");
  }

  // LCD
  lcd.clear();

  lcd.setCursor(0,0);
  lcd.print("S:");
  lcd.print(soil);
  lcd.print("% T:");
  lcd.print(tank);

  lcd.setCursor(0,1);

  if (rain) {
    lcd.print("RAIN -> OFF");
  }
  else if (tank < 20) {
    lcd.print("REFILL WATER!");
  }
  else if (pumpOn) {
    lcd.print("PUMP ON");
  }
  else {
    lcd.print("PUMP OFF");
  }

  delay(1500);
}