/*

Wiring :
LCD           Arduino
SDA     ---->    A4
SCL     ---->    A5
VCC     ---->    5V
GND     ---->    GND
LED     ---->    13
Servo   ---->    7
Keypad:
R1      ---->   3
R2      ---->   2
R3      ---->   1
R4      ---->   0
C1      ---->   A3
C2      ---->   A2
C3      ---->   A1
C4      ---->   A0

    *** O-Tech ***
A Place You Can Trust
https://wa.me/201207738604
https://www.facebook.com/profile.php?id=61555112881938
https://www.youtube.com/@OTECHegypt
*/


#define buzzer 4

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#include <Servo.h>
Servo servo1;
#include <Keypad.h>

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
//define the cymbols on the buttons of the keypads
char hexaKeys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {3, 2, 1, 0}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {A3, A2, A1, A0}; //connect to the column pinouts of the keypad

//initialize an instance of class NewKeypad
Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 
String u_pass = "1234", cur_pass = "", new_pass = "";
byte chg_pass = 0; // 0 : don't change, 1 : enter new pass, 2 : confirm new pass
byte failed_attempt = 0;
int lockout_dur = 5;  // lock the keypad for 5 seconds after 3 failed attempts.
unsigned long int unlocked = 0;
bool reset = false;

void setup(){
  Serial.begin(9600);
  Serial.println("Starting");
  pinMode(13, OUTPUT);
  pinMode(buzzer, OUTPUT);
  servo1.attach(7);
  lcd.init();
  lcd.backlight();
  lcd.print("Enter Password:");
  lcd.setCursor(0, 1);
  delay(1000);
}
  
void loop(){
  char key = customKeypad.getKey();
  if(reset && millis() - unlocked >= 5000){
    lcd.clear();
    lcd.print("Enter Password: ");
    lcd.setCursor(0, 1);
    reset = false;
    unlocked = 0;
    servo1.write(90); // close door
  }
  if (key){
    tone(buzzer, 1000, 25);
    //Serial.println(key);
    if(key == '#'){ // compare passwords here
      // chg_pass 0
      if(chg_pass == 0){
        if(cur_pass == u_pass){
          Serial.println("Password is correct");
          lcd.clear();
          lcd.print("    Unlocked    ");
          servo1.write(0); // open door
          unlocked = millis();
          tone(buzzer, 1000, 150);
          reset = true;
          failed_attempt = 0;
        }
        else{
          failed_attempt++;
          Serial.println("Wrong password");
          lcd.clear();
          lcd.print("wrong pass");
          for(int i = 0; i <= 5; i++){
            tone(buzzer, 5000, 50);
            delay(200);
          }
          lcd.clear();
          lcd.print("failed attempts");
          lcd.setCursor(0, 1);
          lcd.print(failed_attempt);
          delay(1000);
          reset = true;
          if(failed_attempt >= 3){ start_alarm(); } 
        }
      }
      else if(chg_pass == 1){
        // Ask for the old password and verify it first.
        if(cur_pass == u_pass){
          chg_pass = 2;
          Serial.println("Password is correct");
          Serial.println("Enter New Pass"); // numbers only
          lcd.setCursor(0, 0);
          lcd.print("Enter new pass: ");
          clear_line(1);
          lcd.setCursor(0, 1);
        }
        else{
          Serial.print("cur_pass is "); Serial.println(cur_pass);
          chg_pass = 0;
          Serial.println("Wrong Pass"); Serial.println("Press \"*\" to try again");
          lcd.setCursor(0, 0);
          lcd.print("Wrong pass!     ");
          delay(500);
          lcd.print("Press \"*\" to retry");
        }
      }
      else if(chg_pass == 2){ // old pass was entered correctly, now reading new pass for 1st time
        Serial.println("confirm pass");
        lcd.clear();
        lcd.print("Confirm pass:   ");
        lcd.setCursor(0, 1);
        new_pass = cur_pass;
        chg_pass = 3;
      }
      else if(chg_pass == 3){ //now confirming new pass
        if(cur_pass == new_pass){
          Serial.println("Password changed");
          lcd.clear();
          lcd.print("Password changed");
          u_pass = new_pass;
          new_pass = "";
          delay(1000);
          lcd.clear();
          lcd.print("Enter password : ");
          lcd.setCursor(0, 1);
        }
        else{
          Serial.println("pass1 & pass2 don't match");
          Serial.println("press \"*\" to start over");
          lcd.clear();
          lcd.print("pass1 != pass2  ");
          delay(1000);
          lcd.setCursor(0, 1);
          lcd.print("Press * to retry");
          delay(1000);
          new_pass = "";
          reset = true;
        }
        chg_pass = 0;
      }
      cur_pass = "";
    }
    else if(key - '0' >= 0 && key - '0' <= 9){ // use numbers only for the password (no letters or symbols)
      lcd.print("*");
      cur_pass += key;
      //Serial.println(cur_pass);
    }
    if(key == '*'){
      chg_pass = 1;
      Serial.println("Enter old pass");
      lcd.clear();
      lcd.print("Change password ");
      delay(1000);
      lcd.clear();
      lcd.print("Enter old pass :");
      lcd.setCursor(0, 1);
      // move to 2nd line on lcd
      //Serial.println("New Password : "); // confirm current pass before showing this.
    }
  }
}

void start_alarm(){
  lcd.clear();
  lcd.print("Keypad LOCKED!");
  unsigned long int lockout_start = millis();
  int i;
  while(millis() - lockout_start <= lockout_dur * 1000){
    // turn on buzzer/siren/light
    digitalWrite(13, HIGH);
    // flash LCD
    lcd.noBacklight();
    for(i=700;i<800;i+=2){
      tone(buzzer,i);
      delay(1);
    }
    for(i=800;i>700;i--){
      tone(buzzer,i);
      delay(1);
    }//    delay(500);
    digitalWrite(13, LOW);
    lcd.backlight();
    for(i=700;i<800;i+=2){
      tone(buzzer,i);
      delay(1);
    }
    for(i=800;i>700;i--){
      tone(buzzer,i);
      delay(1);
    }
    noTone(buzzer);
  }
  Serial.println("You can try again now");
  lcd.clear();
  lcd.print("Enter password:");
  lcd.setCursor(0, 1);
  failed_attempt = 0;
}


void clear_line(int ln) {
  lcd.setCursor(0, ln);
  lcd.print("                ");
}