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

// --- Configuration ---
LiquidCrystal_I2C lcd(0x27, 20, 4);
RTC_DS1307 rtc;

#define DHTPIN 19
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

#define TRIGGER_PIN  5
#define ECHO_PIN     4
#define MAX_DISTANCE 400 
#define ITERATIONS   7 
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

const int relay1 = 12; // FAN (Temp Control)
const int relay2 = 13; // PUMP (Humid Control)
const int relay3 = 14; // DISTANCE CONTROL (New!)

// --- Timer Variables ---
unsigned long lastSensorRead = 0;
const unsigned long interval = 1000; 

// --- Global Status Variables ---
float t = 0, h = 0;
int distance = 0;
bool r1_status = false;
bool r2_status = false;
bool r3_status = false;

void setup() {
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  rtc.begin();
  dht.begin();
  
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(relay3, OUTPUT);
  
  lcd.clear();
}

void loop() {
  unsigned long currentMillis = millis();

  // --- 1. อ่านค่าจาก Sensor ทุกๆ 1 วินาที ---
  if (currentMillis - lastSensorRead >= interval) {
    lastSensorRead = currentMillis;

    // อ่านค่า DHT22
    float newT = dht.readTemperature();
    float newH = dht.readHumidity();
    if (!isnan(newT)) t = newT;
    if (!isnan(newH)) h = newH;

    // อ่านค่าระยะทาง
    unsigned int uS = sonar.ping_median(ITERATIONS);
    distance = sonar.convert_cm(uS);
    if (distance == 0 && uS == 0) distance = MAX_DISTANCE;

    // --- 2. Hysteresis Logic ---
    
    // R1: พัดลม (Temp >= 30.0 ON / <= 29.5 OFF)
    if (t >= 30.0) r1_status = true;
    else if (t <= 29.5) r1_status = false;

    // R2: ปั๊ม (Humid <= 50.0 ON / >= 52.0 OFF)
    if (h <= 50.0) r2_status = true;
    else if (h >= 52.0) r2_status = false;

    // R3: ระยะทาง (Distance <= 30 ON / >= 35 OFF)
    if (distance <= 30 && distance != 0) r3_status = true;
    else if (distance >= 35) r3_status = false;

    // สั่งงาน Relay
    digitalWrite(relay1, r1_status ? HIGH : LOW);
    digitalWrite(relay2, r2_status ? HIGH : LOW);
    digitalWrite(relay3, r3_status ? HIGH : LOW);
  }

  // --- 3. อัปเดตจอ LCD ---
  updateLCD();
}

void updateLCD() {
  DateTime now = rtc.now();
  char lineBuffer[21];

  // บรรทัดที่ 1: วันที่และเวลา
  lcd.setCursor(0, 0);
  snprintf(lineBuffer, sizeof(lineBuffer), "%02d/%02d/%04d %02d:%02d:%02d", 
           now.day(), now.month(), now.year(), 
           now.hour(), now.minute(), now.second());
  lcd.print(lineBuffer);

  // บรรทัดที่ 2: ระยะทาง
  lcd.setCursor(0, 1);
  snprintf(lineBuffer, sizeof(lineBuffer), "Distance: %3d cm    ", distance);
  lcd.print(lineBuffer);

  // บรรทัดที่ 3: อุณหภูมิและความชื้น
  lcd.setCursor(0, 2);
  char tStr[6], hStr[6];
  dtostrf(t, 4, 1, tStr);
  dtostrf(h, 4, 1, hStr);
  snprintf(lineBuffer, sizeof(lineBuffer), "T:%sC  H:%s%%     ", tStr, hStr);
  lcd.print(lineBuffer);

  // บรรทัดที่ 4: สถานะ Relay ทั้ง 3 ตัว
  lcd.setCursor(0, 3);
  // ใช้ตัวย่อเพื่อให้พอดีกับ 20 ช่อง: R1, R2, R3
  snprintf(lineBuffer, sizeof(lineBuffer), "R1:%s R2:%s R3:%s  ", 
           (r1_status ? "ON " : "OFF"), 
           (r2_status ? "ON " : "OFF"), 
           (r3_status ? "ON " : "OFF"));
  lcd.print(lineBuffer);
}