#include <LiquidCrystal.h>
#include <stdio.h>


// shift register pins initialization
int DATA_PIN = 11; //  Pin connected to DS of 74HC595（Pin14）
int CLK_PIN = 12; // Pin connected to SH_CP of 74HC595（Pin11）
int LATCH_PIN = 13; // Pin connected to ST_CP of 74HC595（Pin12）

// buttons pin initialization
int button1 = 8;
int button2 = 9;
int button3 = 10;

// car parking sensors 
int SENS1 = A0;
int SENS2 = A1;
int SENS3 = A2;
int SENS4 = A3;


// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);


void setup() {

  pinMode(LATCH_PIN, OUTPUT);
  pinMode(CLK_PIN, OUTPUT);
  pinMode(DATA_PIN, OUTPUT);

  pinMode(button1, INPUT);
  pinMode(button2, INPUT);
  pinMode(button3, INPUT);

  lcd.begin(16, 4); // initialize the lcd
  lcd.print("   AVAILABLE");// Print a message to the LCD
  lcd.setCursor(3,1);
  lcd.print("0");
}

void loop() 
{
  /*
  if (digitalRead(P1) == LOW)
  {
    toogleP1 =! toogleP1;
    if(toogleP1 == true) 
    {
      updateLEDsParking(spaceOne, LED_RED);
      counter--;
      delay(100);
    }
    else 
    {
      updateLEDsParking(spaceOne, LED_GREEN);
      counter++;
      delay(100);
    }

    lcd.setCursor(3,1);
    lcd.print("0");
    lcd.print (counter);
    lcd.print(" SPACES");
  }

  if (digitalRead(P2) == LOW)
  {
    toogleP2 =! toogleP2;
    if(toogleP2 == true) 
    {
      updateLEDsParking(spaceTwo, LED_RED);
      counter--;
      delay(100);
    }
    else 
    {
      updateLEDsParking(spaceTwo, LED_GREEN);
      counter++;
      delay(100);
    }
    lcd.setCursor(3,1);
    lcd.print("0");
    lcd.print (counter);
    lcd.print(" SPACES");
  }

  if (digitalRead(P3) == LOW)
  {
    toogleP3 =! toogleP3;
    if(toogleP3 == true) 
    {
      updateLEDsParking(spaceThree, LED_RED);
      counter--;
      delay(100);
    }
    else 
    {
      updateLEDsParking(spaceThree, LED_GREEN);
      counter++;
      delay(100);
    }
    lcd.setCursor(3,1);
    lcd.print("0");
    lcd.print (counter);
    lcd.print(" SPACES");
  }
  if (digitalRead(P4) == LOW)
  {
    toogleP4 =! toogleP4;
    if(toogleP4 == true) 
    {
      updateLEDsParking(spaceFour, LED_RED);
      counter--;
      delay(100);
    }
    else 
    {
      updateLEDsParking(spaceFour, LED_GREEN);
      counter++;
      delay(100);
    }
    lcd.setCursor(3,1);
    lcd.print("0");
    lcd.print (counter);
    lcd.print(" SPACES");
  }

/*
  if (digitalRead(P2) == LOW)
  {
    counter++;
    lcd.setCursor(1,0);
    lcd.print("Counter:       ");
    lcd.setCursor(10,0);
    lcd.print (counter);
    delay(500);
  }
  */
}

/*************************************************************/

/*************************************************************/ /*
void updateShiftRegister()
{
  digitalWrite(latchPin, LOW); // Output low level to latchPin
  shiftOut(dataPin, clockPin, LSBFIRST, LEDs); // Send serial data to 74HC595
  digitalWrite(latchPin, HIGH); // Output high level to latchPin, and 74HC595 will update the data to the parallel output port.
}

/*************************************************************/
/*
void updateLEDsParking(int parkingSpace, int status)
{
  if (parkingSpace == spaceOne)
  {
    if(status) LEDs = ((LEDs&0b10111111)| 0b10000000);
    else LEDs = ((LEDs&0b01111111)|0b01000000);
  }
  if (parkingSpace == spaceTwo)
  {
    if(status) LEDs = ((LEDs&0b11101111)| 0b00100000);
    else LEDs = ((LEDs&0b11011111)|0b00010000);
  }

  if (parkingSpace == spaceThree)
  {
    if(status) LEDs = ((LEDs&0b11111011)| 0b00001000);
    else LEDs = ((LEDs&0b11110111)|0b00000100);
  }

  if (parkingSpace == spaceFour)
  {
    if(status) LEDs = ((LEDs&0b11111110)| 0b00000010);
    else LEDs = ((LEDs&0b11111101)|0b00000001);
  }
  updateShiftRegister();
  delay(200);
}
*/