#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <Servo.h>
#include <SPI.h>
#include <MFRC522.h>

#define SERVO_PIN    9
#define BUZZ_OK      4
#define BUZZ_ERR     5
#define LED_GREEN    6
#define LED_RED      7
#define DHT_PIN     A1
#define MQ2_AOUT    A0
#define VIBR_PIN     2
#define RFID_SS     53
#define RFID_RST    49

const String SECRET  = "1234";
const int    GAS_LIM = 400;
const float  HUM_LIM = 80.0;
const int    MAX_FAIL= 3;
const long   CLOSE_T = 10000;
const long   LOCK_T  = 30000;

const byte CARDS[][4] = {
  {0xDE,0xAD,0xBE,0xEF},
  {0x01,0x02,0x03,0x04}
};
const int NCARD = 2;

const byte ROWS=4, COLS=4;
char keys[ROWS][COLS]={
  {'1','2','3','A'},{'4','5','6','B'},
  {'7','8','9','C'},{'*','0','#','D'}
};
byte rPins[ROWS]={32,33,34,35};
byte cPins[COLS]={36,37,38,39};
Keypad pad=Keypad(makeKeymap(keys),rPins,cPins,ROWS,COLS);

LiquidCrystal_I2C lcd(0x27,16,2);
DHT     dht(DHT_PIN,DHT22);
Servo   srv;
MFRC522 rfid(RFID_SS,RFID_RST);

String        pin="";
int           fails=0;
bool          isOpen=false,locked=false,alarm=false;
unsigned long openAt=0,lockAt=0,sensorAt=0,lcdAt=0;
volatile bool quake=false;

void quakeISR(){ quake=true; }

void setup(){
  Serial.begin(9600);
  pinMode(BUZZ_OK,  OUTPUT); digitalWrite(BUZZ_OK,  LOW);
  pinMode(BUZZ_ERR, OUTPUT); digitalWrite(BUZZ_ERR, LOW);
  pinMode(LED_GREEN,OUTPUT); digitalWrite(LED_GREEN,LOW);
  pinMode(LED_RED,  OUTPUT); digitalWrite(LED_RED,  LOW);
  pinMode(VIBR_PIN, INPUT);

  srv.attach(SERVO_PIN);
  srv.write(0);  delay(800);
  srv.write(90); delay(800);
  srv.write(0);  delay(800);

  attachInterrupt(digitalPinToInterrupt(VIBR_PIN),quakeISR,RISING);
  dht.begin();
  SPI.begin();
  rfid.PCD_Init();
  delay(50);

  lcd.init(); lcd.backlight(); lcd.clear();
  lcd.setCursor(0,0); lcd.print("SMART DOOR  v9.0");
  lcd.setCursor(0,1); lcd.print("Starting...     ");
  beepBoot();
  delay(1000);
  prompt();
  Serial.println(F("Ready. PIN=1234"));
}

void loop(){
  doQuake(); doSensors(); doRFID();
  doKeypad(); doAutoClose(); doLockout();
}

void openDoor(){
  isOpen=true; openAt=millis();
  srv.write(90);
  digitalWrite(LED_GREEN,HIGH);
  Serial.println(F("[DOOR] OPEN"));
}

void closeDoor(){
  if(alarm) return;
  isOpen=false;
  srv.write(0);
  digitalWrite(LED_GREEN,LOW);
  Serial.println(F("[DOOR] CLOSED"));
  prompt();
}

void doAutoClose(){
  if(!isOpen||alarm) return;
  if(millis()-openAt>(unsigned long)CLOSE_T) closeDoor();
}

void doQuake(){
  if(!quake) return;
  quake=false; alarm=true;
  digitalWrite(LED_RED,HIGH);
  lcd.clear();
  lcd.setCursor(0,0); lcd.print("!! EARTHQUAKE !!");
  lcd.setCursor(0,1); lcd.print("DOOR OPENING!   ");
  openDoor();
  for(int i=0;i<8;i++){
    digitalWrite(BUZZ_ERR,HIGH); delay(150);
    digitalWrite(BUZZ_ERR,LOW);  delay(150);
  }
  alarm=false; digitalWrite(LED_RED,LOW);
  prompt();
}

void doSensors(){
  if(millis()-sensorAt<2000) return;
  sensorAt=millis();
  int   gas=analogRead(MQ2_AOUT);
  float hum=dht.readHumidity();
  float tmp=dht.readTemperature();
  Serial.print(F("Gas:")); Serial.print(gas);
  Serial.print(F(" H:")); Serial.print(isnan(hum)?0:hum);
  Serial.print(F(" T:")); Serial.println(isnan(tmp)?0:tmp);

  if(gas>GAS_LIM){
    alarm=true; digitalWrite(LED_RED,HIGH);
    lcd.clear();
    lcd.setCursor(0,0); lcd.print("** GAS ALERT!! **");
    lcd.setCursor(0,1); lcd.print("EVACUATE! OPEN! ");
    openDoor();
    for(int i=0;i<10;i++){
      digitalWrite(BUZZ_ERR,HIGH); delay(100);
      digitalWrite(BUZZ_ERR,LOW);  delay(150);
    }
    alarm=false; digitalWrite(LED_RED,LOW);
    prompt(); return;
  }

  if(!isnan(hum)&&hum>HUM_LIM){
    lcd.clear();
    lcd.setCursor(0,0); lcd.print("HIGH HUMIDITY!  ");
    lcd.setCursor(0,1); lcd.print("DOOR OPENING!   ");
    openDoor();
    digitalWrite(BUZZ_ERR,HIGH); delay(600);
    digitalWrite(BUZZ_ERR,LOW);
    return;
  }

  if(!alarm&&!locked&&!isOpen&&millis()-lcdAt>4000){
    lcdAt=millis();
    if(!isnan(hum)&&!isnan(tmp)){
      lcd.setCursor(0,1);
      lcd.print("H:"); lcd.print((int)hum);
      lcd.print("% T:"); lcd.print((int)tmp);
      lcd.print((char)223); lcd.print("C   ");
    }
  }
}

void doRFID(){
  if(locked||alarm) return;
  if(!rfid.PICC_IsNewCardPresent()) return;
  if(!rfid.PICC_ReadCardSerial())   return;
  Serial.print(F("[RFID] UID:"));
  for(byte i=0;i<rfid.uid.size;i++){
    Serial.print(rfid.uid.uidByte[i]<0x10?" 0":" ");
    Serial.print(rfid.uid.uidByte[i],HEX);
  }
  Serial.println();
  if(cardOK()){
    fails=0; lcd.clear();
    lcd.setCursor(0,0); lcd.print("** RFID OK !!  **");
    lcd.setCursor(0,1); lcd.print("Welcome!        ");
    beepOK(); openDoor(); delay(1000); prompt();
  }else{
    fails++; lcd.clear();
    lcd.setCursor(0,0); lcd.print("RFID DENIED!    ");
    lcd.setCursor(0,1); lcd.print("Unknown card    ");
    beepFail();
    if(fails>=MAX_FAIL) startLock();
    else{ delay(1000); prompt(); }
  }
  rfid.PICC_HaltA(); rfid.PCD_StopCrypto1();
}

bool cardOK(){
  for(int c=0;c<NCARD;c++){
    bool ok=true;
    for(byte b=0;b<4;b++)
      if(rfid.uid.uidByte[b]!=CARDS[c][b]){ok=false;break;}
    if(ok) return true;
  }
  return false;
}

void doKeypad(){
  if(locked||alarm) return;
  char k=pad.getKey(); if(!k) return;
  Serial.print(F("Key:")); Serial.println(k);
  if(k=='#'){ checkPIN(); }
  else if(k=='*'){ pin=""; if(isOpen) closeDoor(); else prompt(); }
  else{
    if(pin.length()<8){
      pin+=k;
      lcd.setCursor(0,1); lcd.print("PIN: ");
      for(unsigned int i=0;i<pin.length();i++) lcd.print('*');
      for(unsigned int i=pin.length();i<11;i++) lcd.print(' ');
    }
  }
}

void checkPIN(){
  if(pin==SECRET){
    fails=0; alarm=false; digitalWrite(LED_RED,LOW);
    lcd.clear();
    lcd.setCursor(0,0); lcd.print("** ACCESS OK!! **");
    lcd.setCursor(0,1); lcd.print("Welcome!        ");
    beepOK(); openDoor(); delay(1000); prompt();
  }else{
    fails++;
    lcd.clear();
    lcd.setCursor(0,0); lcd.print("WRONG PIN!      ");
    lcd.setCursor(0,1); lcd.print("Left:"); lcd.print(MAX_FAIL-fails);
    beepFail();
    if(fails>=MAX_FAIL) startLock();
    else{ delay(1000); prompt(); }
  }
  pin="";
}

void startLock(){
  locked=true; alarm=true; lockAt=millis();
  digitalWrite(LED_RED,HIGH);
  lcd.clear();
  lcd.setCursor(0,0); lcd.print("** LOCKED OUT **");
  lcd.setCursor(0,1); lcd.print("Wait 30s...     ");
  for(int i=0;i<6;i++){
    digitalWrite(BUZZ_ERR,HIGH); delay(100);
    digitalWrite(BUZZ_ERR,LOW);  delay(150);
  }
}

void doLockout(){
  if(!locked) return;
  unsigned long el=millis()-lockAt;
  if(millis()-lcdAt>1000){
    lcdAt=millis();
    long r=((long)LOCK_T-(long)el)/1000; if(r<0)r=0;
    lcd.setCursor(0,1); lcd.print("Wait: ");
    if(r<10) lcd.print(' '); lcd.print(r); lcd.print("s       ");
  }
  if(el>=(unsigned long)LOCK_T){
    locked=false; alarm=false; fails=0;
    digitalWrite(BUZZ_ERR,LOW); digitalWrite(LED_RED,LOW);
    prompt();
  }
}

void beepBoot(){
  for(int i=0;i<3;i++){
    digitalWrite(BUZZ_OK,HIGH); delay(80);
    digitalWrite(BUZZ_OK,LOW);  delay(80);
  }
}
void beepOK(){
  digitalWrite(BUZZ_OK,HIGH); delay(200);
  digitalWrite(BUZZ_OK,LOW);  delay(80);
  digitalWrite(BUZZ_OK,HIGH); delay(400);
  digitalWrite(BUZZ_OK,LOW);
}
void beepFail(){
  for(int i=0;i<3;i++){
    digitalWrite(BUZZ_ERR,HIGH); delay(100);
    digitalWrite(BUZZ_ERR,LOW);  delay(150);
  }
}

void prompt(){
  lcd.clear();
  lcd.setCursor(0,0); lcd.print(isOpen?"DOOR: OPEN      ":"DOOR: LOCKED    ");
  lcd.setCursor(0,1); lcd.print("PIN/RFID: # OK  ");
}