#include <LiquidCrystal_I2C.h>

#define PIN_ULTRASONIC_ECHO (2)
#define PIN_ULTRASONIC_TRIGGER (7)

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

#define DOWN_BUTTON (10)
#define UP_BUTTON (11)
#define POWER_BUTTON (12)

//Gombok
int DOWN_BUTTON_OLDSTATE ;  //MENU DOWN Button 
int UP_BUTTON_OLDSTATE ;   // MENU UP BUtton
int POWER_BUTTON_OLDSTATE ; // PR POWER BUTTON
int DOWN_BUTTON_STATE ;  //MENU DOWN Button 
int UP_BUTTON_STATE ;   // MENU UP BUtton
int POWER_BUTTON_STATE ; // PR POWER BUTTON
unsigned long(POWER_BUTTON_START) = millis();
unsigned long(UP_BUTTON_START) = millis();
unsigned long(DOWN_BUTTON_START) = millis();

// Mérés
void isr_us(void);
unsigned long us_start;
unsigned long us_end;
unsigned long us_time;
bool measurementReady = false;
bool us_start_state = false;
bool us_end_state = false;


// LCD Függvényei
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);
void lcd_clear (void);
void lcd_default (void);
void lcd_time_write(float);

void setup() {
  
  Serial.begin(9600);
  
  // Init LCD
  lcd.init();
  lcd.backlight();
  lcd_default();

  // Init PR Interupt 
  pinMode(PIN_ULTRASONIC_ECHO, INPUT_PULLUP);
  pinMode(PIN_ULTRASONIC_TRIGGER, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(PIN_ULTRASONIC_ECHO), isr_us, CHANGE);

  // Init BUTTONS 
  pinMode(DOWN_BUTTON, INPUT_PULLUP);
  pinMode(UP_BUTTON, INPUT_PULLUP);
  pinMode(POWER_BUTTON, INPUT_PULLUP);
  DOWN_BUTTON_OLDSTATE = digitalRead(DOWN_BUTTON);  //MENU DOWN Button 
  UP_BUTTON_OLDSTATE = digitalRead(UP_BUTTON);    // MENU UP BUtton
  POWER_BUTTON_OLDSTATE = digitalRead(POWER_BUTTON);  // PR POWER BUTTON

  digitalWrite(PIN_ULTRASONIC_TRIGGER, HIGH);
}

void loop() {
  
  // Ha a mérés kész
  if (measurementReady){
    noInterrupts();
    measurementReady = false;
    unsigned long timeDelta =  us_end - us_start;
    interrupts();
    if (timeDelta != 0) {
    lcd_time_write(timeDelta);
    Serial.println(timeDelta);
    }
  }
  // POWER BUTTON RED
  POWER_BUTTON_STATE = digitalRead(POWER_BUTTON); 
  if (POWER_BUTTON_STATE != POWER_BUTTON_OLDSTATE and millis() >= POWER_BUTTON_START + 5)  {
    POWER_BUTTON_OLDSTATE = POWER_BUTTON_STATE;
    if (POWER_BUTTON_STATE == HIGH) {
      // RELEASED
      POWER_BUTTON_START = millis();             
    }
    if (POWER_BUTTON_STATE == LOW) {
      // PRESSED
      POWER_BUTTON_START = millis();
      int triggerState = !digitalRead(PIN_ULTRASONIC_TRIGGER);
      digitalWrite(PIN_ULTRASONIC_TRIGGER, triggerState);
      lcd_clear ();
      lcd.setCursor(0, 0);
      lcd.print("READY: ");
      if (triggerState) {
        lcd.print("ON");
      }  
      else {
        lcd.print("OFF");
      } 
    }
  }
  // UP BUTTON BLUE
  UP_BUTTON_STATE = digitalRead(UP_BUTTON); 
  if (UP_BUTTON_STATE != UP_BUTTON_OLDSTATE and millis() >= UP_BUTTON_START + 5)  {
    UP_BUTTON_OLDSTATE = UP_BUTTON_STATE;
    if (UP_BUTTON_STATE == HIGH) {
      // RELEASED
      UP_BUTTON_START = millis();
      lcd_clear ();
      int AO = 1024 - analogRead(7);
      lcd.setCursor(0, 0);
      lcd.print("LIGHTE : ");
      lcd.print(AO);
      lcd.setCursor(0, 1);
      lcd.print("                ");
      lcd.setCursor(0, 1);
      for ( int i = 0; i <= AO/64; i++){
        lcd.print("#");              
      }
    }
    if (UP_BUTTON_STATE == LOW) {
      // PRESSED
      UP_BUTTON_START = millis();
    }
  } 
  // DOWN BUTTON YELLOW
  DOWN_BUTTON_STATE = digitalRead(DOWN_BUTTON); 
  if (DOWN_BUTTON_STATE != DOWN_BUTTON_OLDSTATE and millis() >= DOWN_BUTTON_START + 5)  {
    DOWN_BUTTON_OLDSTATE = DOWN_BUTTON_STATE;
    if (DOWN_BUTTON_STATE == HIGH) {
      // RELEASED
      DOWN_BUTTON_START = millis();             
    }
    if (DOWN_BUTTON_STATE == LOW) {
      // PRESSED
      DOWN_BUTTON_START = millis();
    }
  }
}  //loop END

void isr_us(void){
  if (measurementReady == false) {
    us_time = millis();
    bool ECHO = digitalRead(PIN_ULTRASONIC_ECHO);
  
    if (ECHO == LOW and us_start_state == false){
      us_start = millis();
      us_start_state = true;
      us_end_state = false;
      //Serial.println("S");
    } else if (ECHO == HIGH and us_end_state == false){
      measurementReady = true;
      us_end = millis();
      us_end_state = true;
      us_start_state = false;
      //Serial.println("E");
    }
  }
}

void lcd_clear (void){
  lcd.setCursor(0, 0);
  lcd.print("                    ");
  lcd.setCursor(0, 1);
  lcd.print("                    ");
}

void lcd_default (void) {
  lcd.setCursor(0, 0);
  lcd.print("SHUTTER SPEED ");
  lcd.setCursor(0, 1);
  lcd.print("     TESTER 2024");
}

void lcd_time_write(float timeDelta){
    int ezer = 0;
    float time =0;
    if (timeDelta > 1000) {
      ezer = (timeDelta / 1000 );
      timeDelta = timeDelta - (ezer * 1000) ;
      time = 1 / float (timeDelta /1000);
      Serial.print("time>1000:"); 
      Serial.println(ezer);
      Serial.println(time);
    }
    else if (timeDelta > 100){
      time = 1 / float (timeDelta /1000);
      Serial.print("time>100:"); 
      Serial.println(time);  
    }
    else {
      time = 1000 * (1 / timeDelta);
      Serial.print("time<100:"); 
      Serial.println(time);
    }

    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(0, 1);
    lcd.print("Time:");
    lcd.print(ezer);
    lcd.setCursor(7, 1);
    lcd.print("+ 1/");
    lcd.print(time);

}