#include "LiquidCrystal_I2C.h"
#include <Wire.h>

#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int count = 0;
int MAX = 8;

int lastState0 = 1;
int lastState1 = 1;

void setup() {
  Serial.begin(115200);

  Wire.begin();
  lcd.init();
  lcd.backlight();

  pinMode(PA0, INPUT_PULLUP); // entrée
  pinMode(PA1, INPUT_PULLUP); // sortie

  pinMode(PA2, OUTPUT); // 🔴 rouge
  pinMode(PA3, OUTPUT); // 🟢 verte

  lcd.setCursor(0,0);
  lcd.print("Parking System");
  lcd.setCursor(0,1);
  lcd.print("Ready...");
  delay(1500);
}

void loop() {

  int state0 = digitalRead(PA0);
  int state1 = digitalRead(PA1);

  // -------- Entrée --------
  if(state0 == LOW && lastState0 == HIGH)
  {
    if(count < MAX) count++;
  }

  // -------- Sortie --------
  if(state1 == LOW && lastState1 == HIGH)
  {
    if(count > 0) count--;
  }

  lastState0 = state0;
  lastState1 = state1;

  // -------- LCD --------
  lcd.setCursor(0,0);
  lcd.print("Voitures: ");
  lcd.print(count);
  lcd.print("   ");

  lcd.setCursor(0,1);
  lcd.print("Places: ");
  lcd.print(MAX - count);
  lcd.print("   ");

  // -------- LEDs --------
  if(count == MAX)
  {
    lcd.setCursor(0,2);
    lcd.print("PARKING FULL     ");

    digitalWrite(PA2, HIGH); // 🔴 rouge ON
    digitalWrite(PA3, LOW);  // 🟢 verte OFF
  }
  else
  {
    lcd.setCursor(0,2);
    lcd.print("                ");

    digitalWrite(PA2, LOW);  // 🔴 rouge OFF
    digitalWrite(PA3, HIGH); // 🟢 verte ON
  }

  delay(20); // ⚡ très rapide (réponse instantanée)
}