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

// ===== LCD =====
LiquidCrystal_I2C lcd(0x27, 20, 4);

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

// ===== Sensors =====
#define LDR_PIN A0
#define MQ2_PIN A1

// ===== RGB PINS =====
// Light RGB
#define LR 3
#define LG 4
#define LB 5

// AC RGB
#define AR 6
#define AG 7
#define AB 8

// Purifier RGB
#define PR 9
#define PG 10
#define PB 11

// ===== RELAY PINS =====
#define RELAY_LIGHT 12
#define RELAY_AC 13
#define RELAY_PURIFIER A2   // works as digital pin

// ===== Thresholds =====
int darkThreshold = 400;
float tempThreshold = 30.0;
int airThreshold = 300;

// ===== RGB Helper =====
void setRGB(int r, int g, int b, bool red, bool green, bool blue) {
  digitalWrite(r, red);
  digitalWrite(g, green);
  digitalWrite(b, blue);
}

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

  // RGB pins
  int rgbPins[] = {LR,LG,LB, AR,AG,AB, PR,PG,PB};
  for (int i = 0; i < 9; i++) pinMode(rgbPins[i], OUTPUT);

  // Relay pins
  pinMode(RELAY_LIGHT, OUTPUT);
  pinMode(RELAY_AC, OUTPUT);
  pinMode(RELAY_PURIFIER, OUTPUT);

  // Turn relays OFF (ACTIVE LOW)
  digitalWrite(RELAY_LIGHT, HIGH);
  digitalWrite(RELAY_AC, HIGH);
  digitalWrite(RELAY_PURIFIER, HIGH);

  dht.begin();
  lcd.init();
  lcd.backlight();

  // System Ready → Pink
  setRGB(LR,LG,LB, HIGH, LOW, HIGH);
  setRGB(AR,AG,AB, HIGH, LOW, HIGH);
  setRGB(PR,PG,PB, HIGH, LOW, HIGH);

  lcd.setCursor(0,0);
  lcd.print("System Ready");
  delay(2000);
}

void loop() {

  int ldrValue = analogRead(LDR_PIN);
  int airValue = analogRead(MQ2_PIN);
  float temp = dht.readTemperature();

  // ===== LIGHT =====
  bool lightON = ldrValue > darkThreshold;
  digitalWrite(RELAY_LIGHT, lightON ? LOW : HIGH);
  setRGB(LR,LG,LB, LOW, lightON, LOW);

  // ===== AC =====
  bool acON = temp >= tempThreshold;
  digitalWrite(RELAY_AC, acON ? LOW : HIGH);
  setRGB(AR,AG,AB, LOW, acON, LOW);

  // ===== PURIFIER =====
  bool purifierON = airValue >= airThreshold;
  digitalWrite(RELAY_PURIFIER, purifierON ? LOW : HIGH);
  setRGB(PR,PG,PB, LOW, purifierON, LOW);

  // ===== LCD =====
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Temp: ");
  lcd.print(temp);
  lcd.print(" C");

  lcd.setCursor(0,1);
  lcd.print("Light: ");
  lcd.print(ldrValue);

  lcd.setCursor(0,2);
  lcd.print("Air: ");
  lcd.print(airValue);

  lcd.setCursor(0,3);
  lcd.print("L:");
  lcd.print(lightON ? "ON " : "OFF");
  lcd.print(" AC:");
  lcd.print(acON ? "ON " : "OFF");
  lcd.print(" P:");
  lcd.print(purifierON ? "ON" : "OFF");

  delay(1500);
}