#include <Keypad.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Servo.h>


#define ROW_NUM     4 // four rows
#define COLUMN_NUM  4 // four columns

char key = '\0';  //  null key
String input_password = "";
String user_password = "6969";
String door_state = "open";
String prev_door_state = "open";

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
Servo myServo;

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte pin_rows[ROW_NUM]      = {7, 6, 5, 4}; // GIOP19, GIOP18, GIOP5, GIOP17 connect to the row pins
byte pin_column[COLUMN_NUM] = {3, 2, 8, 9}; // GIOP16, GIOP4, GIOP0, GIOP2 connect to the column pins

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );




void setup() {
  Serial.begin(9600);
  myServo.attach(13);
  myServo.write(100);
  delay(3000);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
  Serial.println("SSD1306 allocation failed");
  for (;;);
}
  display_message("Welcome to your personal lock services");
}

void loop() {
 door_check();
 delay(1000);
}

void display_message(String message){
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.clearDisplay();
  display.setCursor(10, 20);
  display.print(message);
  display.display();
}



void check_password() {
  delay(3000);
  display_message("Enter Password. Press # when password entered : ");
  while (true) {
    key = keypad.getKey();
    if (key) {
      if (key == '#') {
        if (input_password == user_password) {  
          if(prev_door_state == "open"){
            door_state = "close";
            display_message("closing");
          }
          else if(prev_door_state == "close"){
            door_state = "open";
            display_message("opening");
          }
          prev_door_state = door_state;
          input_password = "";
          break;
        }
        else {
          display_message("Wrong password try again");
          input_password = "";

        }
      }
      input_password.concat(key);
      display.setTextSize(1);
      display.setTextColor(WHITE);
      display.print("*");
      display.print(" ");
      display.display();
    }
  }
}

void door_check(){
  check_password();
  delay(1000);

  if(door_state == "open"){
    myServo.write(0);
    delay(100);
  }
  else if(door_state == "close"){
    myServo.write(180);
    delay(100);
  }
  delay(1000);
}