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

#define SOIL_PIN 34
#define PH_PIN 35
#define DHT_PIN 4
#define PUMP_PIN 25
#define BUZZER_PIN 26

#define DHTTYPE DHT22
DHT dht(DHT_PIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 20, 4); //I2C LCD 20x4

int soilThresh = 500; //Soil moisture threshold (in ml)
float tempThresh = 32.0; //Temperature threshold (in Celsius degrees)
float tempColdThresh = 10.0; //Temperature threshold (when too cold)
float humidityThresh = 85.0; //Humidity threshold (%)

unsigned long dryStartTime = 0;
bool buzzerOn = false;
bool pumpOn = false;

void setup() {
  Serial.begin(115200);
  dht.begin();
  lcd.init();
  lcd.backlight();

  pinMode(PUMP_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(PUMP_PIN, LOW);
  digitalWrite(BUZZER_PIN, LOW);

  //Show welcome screen once
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("BotanIQ");
  lcd.setCursor(0, 1);
  lcd.print("by IoT Group 3");
  lcd.setCursor(0, 2);
  lcd.print("Taylor's University");
  delay(3000);
}

void loop() {
  int ph = analogRead(PH_PIN);
  delay(10);
  int soil = analogRead(SOIL_PIN);
  float voltage = ph * (3.3 / 4095.0); //Convert to voltage
  float pHValue = mapf(voltage, 0.0, 3.3, 0.0, 14.0); //Map voltage to pH range
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  //If DHT does not work
  if (isnan(temp) || isnan(hum)) {
    Serial.println("❌ Failed to read from DHT sensor!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("DHT Sensor Error!");
  }

  //Serial Monitor output
  Serial.printf("Soil Moisture = %dml, pH Level = %.2f, Temperature = %.1f°C, Humidity = %.1f%%\n", soil, pHValue, temp, hum);

  //LCD output
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.printf("Soil: %dml", soil);
  lcd.setCursor(0, 1);
  lcd.printf("pH Level: %.2f", pHValue);
  lcd.setCursor(0, 2);
  lcd.printf("Temperature: %.1f%cC", temp, 223);
  lcd.setCursor(0, 3);
  lcd.printf("Humidity: %.1f%%", hum);
  delay(3000);

  //Status flags
  bool isDry = (soil < soilThresh);
  bool isHot = (temp >= tempThresh);
  bool isCold = (temp < tempColdThresh);
  bool isTooHumid = (hum >= humidityThresh);
  bool isTooAcidic = (pHValue < 4.0);
  bool isTooAlkaline = (pHValue > 10.5);

  //Alert Priority System
  //Soil moisture & water pump
  if (isDry) { 
    if (!buzzerOn) {
      tone(BUZZER_PIN, 2000, 300);
      dryStartTime = millis();
      buzzerOn = true;
      pumpOn = false;
      digitalWrite(PUMP_PIN, LOW);
      Serial.println("🚨 Soil is dry!");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Soil is dry!");
      delay(3000);

    }

    if (buzzerOn && (millis() - dryStartTime >= 3000) && !pumpOn) { //3 seconds passed since Buzzer is on
      digitalWrite(PUMP_PIN, HIGH); //Turn on LED
      tone(BUZZER_PIN, 2000, 300); 
      pumpOn = true;
      Serial.println("💧 Water Pump ON (LED)");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Watering the plant");
      delay(3000);

    }
  } else { //Reset if soil is no longer dry
    digitalWrite(PUMP_PIN, LOW);
    noTone(BUZZER_PIN);
    buzzerOn = false;
    pumpOn = false;
  }

  //Critical alerts
  //Temperature too hot
  if (isHot) {
    tone(BUZZER_PIN, 2000, 300);
    Serial.println("🌡️ It's hot!");
    lcd.clear();
    lcd.setCursor(0, 2);
    lcd.print("It's hot!");
    delay(3000);
  }

  //Temperature too cold
  if (isCold) {
    tone(BUZZER_PIN, 2000, 300);
    Serial.println("❄️ It's too cold!");
    lcd.clear();
    lcd.setCursor(0, 2);
    lcd.print("It's too cold!");
    delay(3000);
  }

  //Too humid for the plant
  if (isTooHumid) {
    tone(BUZZER_PIN, 2000, 300);
    Serial.println("💦 Too humid!");
    lcd.clear();
    lcd.setCursor(0, 3);
    lcd.print("Too humid!");
    delay(3000);
  }

  //pH level too acidic
  if (isTooAcidic) {
    tone(BUZZER_PIN, 2000, 300);
    Serial.println("⚠️ Soil too acidic!");
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("Soil too acidic!");
    delay(3000);
  } 
  
  //pH level to alkaline
  if (isTooAlkaline) {
    tone(BUZZER_PIN, 2000, 300);
    Serial.println("⚠️ Soil too alkaline!");
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("Soil too alkaline!");
    delay(3000);
  } 
}

//Function to map float values
float mapf(float x, float in_min, float in_max, float out_min, float out_max) {
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}