#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 4; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {7, 6, 5, 4}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {3, 2, 1, 0}; //connect to the column pinouts of the keypad
#define BUZZER 12
#define GREEN_LED 9
#define BLUE_LED 10
#define RED_LED 11
#define RELAY 8
#define BUTTON 13
#define LONG_BUZZ 2
#define SHORT_BUZZ 1
#define LONG_THRESH 100
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
LiquidCrystal_I2C lcd(0x27, 16, 2);
char password[4]={'1','7','0','1'};
char user[4];

int buzz_password[4] = {LONG_BUZZ, SHORT_BUZZ, LONG_BUZZ, LONG_BUZZ};
int buzz_user[4];

int pass_index=0;
bool user_done=false;
int lastState = HIGH;
int buzz_index=0;
int start_time, stop_time, pressed_time;
bool buzz_user_done=false;



void setup(){
  init_buzzer();
  init_RGB();
  init_relay();
  init_LCD();
  init_button();
}
void loop(){
  //test_all();
  main_logic();
}
void main_logic()
{
 get_keypad();
 get_buzz();
 if(user_done || buzz_user_done)
 {
  if (check_password() || check_buzz_password())
  {
   open_door();
  }
  else
  {
    lcd.print("Error");
  }
  user_done=false;
  buzz_user_done=false;
 }
}
//init
void init_buzzer()
{
  pinMode(BUZZER, OUTPUT);
}
void init_button()
{
  pinMode(BUTTON, INPUT_PULLUP);
}
void init_RGB()
{
  pinMode(GREEN_LED, OUTPUT);
  pinMode(BLUE_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
}
void init_relay()
{
  pinMode(RELAY, OUTPUT);
}
void init_LCD()
{
  lcd.init();
  lcd.clear();
  lcd.backlight();
  lcd.home();
}

//buzzer
void play_buzzer(int time)
{
  tone(BUZZER, 2000);
  delay(time);
}
void stop_buzzer()
{
  noTone(BUZZER);
}
//rgb led
void rgb_led(int red,int green,int blue)
{
  analogWrite(RED_LED,red);
  analogWrite(BLUE_LED,blue);
  analogWrite(GREEN_LED,green);
}
void led_off()
{
  rgb_led(0,0,0);
}
//relay
void open_lock(int time)
{
  digitalWrite(RELAY, HIGH);
  delay(time);
}
void close_lock()
{
  digitalWrite(RELAY, LOW);
}
//test
void test_all()
{
  //test_buzzer();
  //test_led();
 // test_relay();
 // test_LCD();
  //test_keypad();
  //test_button();
  get_buzz();
}
void test_buzzer()
{
  play_buzzer(1000);
  stop_buzzer();
  delay(1000);
}
void test_button()
{
  int value = digitalRead((BUTTON));
  lcd.setCursor(0,0);
  if (lastState != value) {
    lastState = value;
    if (value == HIGH) {
      lcd.print(" released");
    }
    if (value == LOW) {
      lcd.println(" pressed");
    }
  }
  delay(50);
}
void test_led()
{
  rgb_led(255,0,0);
  delay(1000);
  rgb_led(0,255,0);
  delay(1000);
  led_off();
  delay(1000);
}
void test_relay()
{
 open_lock(2000);
 close_lock();
 delay(1000);
}
void test_LCD()
{
  lcd.setCursor(3,0);
   lcd.print("Hello world");
   delay(1000);
   lcd.setCursor(5,1);
   lcd.print("Goodbye");
   delay(1000);
   lcd.clear();
  delay(1000);
}
void test_keypad()
{
  char key = keypad.getKey();
  
  if (key){
    lcd.print(key);
  }
}
//mainlogic
void get_keypad()
{
  char key = keypad.getKey();
  if (key){
    lcd.print(key);
    user[pass_index]=key;
    if(pass_index==3)
    {
      user_done=true;
      pass_index=0;
    }
    else
    {
      user_done=false;
      pass_index++;
    }
  }
}
bool check_password()
{
  for(int j=0;j<4;j++)
  {
    if(user[j] != password[j])
    return false;
  }
  return true;
}
void open_door()
{
  lcd.clear();
  lcd.print("OK");
  open_lock(5000);
  user_done = false;
  close_lock();
}
bool door_bell()
{
  int value = digitalRead((BUTTON));
  //lcd.setCursor(0,0);
  if (lastState != value) {
    lastState = value;
    if (value == HIGH) {
      //lcd.print(" released");
      stop_buzzer();
      stop_time = millis();
      /*
      lcd.setCursor(0,1);
      lcd.print("stop = ");
      lcd.println(stop_time);
      */
      pressed_time = stop_time - start_time;
      delay(1000);
      return true;
    }
    if (value == LOW) {
      //lcd.println(" pressed");
      tone(BUZZER, 700);
      start_time = millis();
      lcd.clear();
      /*
      lcd.setCursor(0,0);
      lcd.print("start = ");
      lcd.print(start_time);
      */
      return false;
    }
   
  }
   return false;
}
void get_buzz()
{
  int buzz;
  if (door_bell())
  {
      /*
      lcd.setCursor(0,0);
      lcd.print("pressed ");
      lcd.setCursor(12,0);
      lcd.print(pressed_time);
      */
      if (pressed_time > LONG_THRESH)
        buzz = LONG_BUZZ;
      else
        buzz = SHORT_BUZZ;
      buzz_user[buzz_index] = buzz;
      //lcd.setCursor(0,1);
      lcd.print(buzz);
      if(buzz_index==3)
      {
        buzz_user_done=true;
        buzz_index=0;
      }
      else
      {
        buzz_user_done=false;
        buzz_index++;
      }
  }
}
bool check_buzz_password()
{
  lcd.print("checking");
  for(int j=0;j<4;j++)
  {
    if(buzz_user[j] != buzz_password[j])
        return false;
        
  }
  return true;
}