#include <Arduino.h>
#include <U8x8lib.h>

// megszakítás
#define PIN_SENSOR_ECHO (2)
#define PIN_SENSOR_TRIGGER (7)
// gombok
#define DOWN_BUTTON (10)
#define UP_BUTTON (11)
#define POWER_BUTTON (12)
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();
// LEDek
#define DO_LED (3)
// Mérés
void isr_us(void);
unsigned long us_start;
unsigned long us_end;
bool measurementReady = false;
bool us_start_state = false;
bool us_end_state = false;
unsigned long timeDelta;
bool TEST_State = false;

// OLED u8x8
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ A5, /* data=*/ A4, /* reset=*/ U8X8_PIN_NONE);
U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/* clock=*/ 22, /* data=*/ 21, /* reset=*/ U8X8_PIN_NONE);

void oled_time_write(float);
void oled_default(void);
char buff[7];

// Serial
void serial_default(void);

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

void setup() {

Serial.begin(9600);
  
  // Init PR Interupt 
  pinMode(PIN_SENSOR_ECHO, INPUT_PULLUP);
  pinMode(PIN_SENSOR_TRIGGER, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(PIN_SENSOR_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

  // Init LED
  pinMode(DO_LED, OUTPUT);

  // Wokwi-photoresistor-sensor ON
  digitalWrite(PIN_SENSOR_TRIGGER, HIGH);  

  // Oled and Serial default
    u8x8.begin();
  
  oled_default();
  serial_default();
  u8x8.refreshDisplay();	
}

//**************************************************************************************************
void loop() {

 // Ha a mérés kész
  if (measurementReady and TEST_State == false){
    noInterrupts();
    measurementReady = false;
    timeDelta =  (us_end - us_start) /100;
    interrupts();
    if (timeDelta != 0) {
    oled_time_write(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
      TEST_State = false;
      measurementReady = false;
      POWER_BUTTON_START = millis();
      int triggerState = !digitalRead(PIN_SENSOR_TRIGGER);
      digitalWrite(PIN_SENSOR_TRIGGER, triggerState);
      oled_default();
      u8x8.setFont(u8x8_font_8x13B_1x2_f);
      u8x8.setCursor(0, 4);
      u8x8.print("READY: ");
      if (triggerState) {
        u8x8.print("ON");
        serial_default();
      }  
      else {
        u8x8.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();
      TEST_State = !TEST_State;
      measurementReady = false;
      oled_default();
      if (TEST_State == false) {
        serial_default();
      }
    }
    if (UP_BUTTON_STATE == LOW) {
      // PRESSED
      UP_BUTTON_START = millis();

    }
  }
  if (TEST_State == true){
      int AO = 1024 - analogRead(7);
      u8x8.setFont(u8x8_font_8x13B_1x2_f);
      u8x8.setCursor(0, 3);
      u8x8.print("LIGHTE : ");
      u8x8.print(AO);
      u8x8.print("  ");
      u8x8.setCursor(0, 5);
      for ( int i = 0; i <= 13; i++){
        if (i <= AO/74) {
          u8x8.print("#");              
        }
        else {
          u8x8.print(" ");              
        }
      }
  }

} //LOOP end


//**************************************************************************************************
void isr_us(void){
  bool ECHO = digitalRead(PIN_SENSOR_ECHO);
  digitalWrite(DO_LED, !ECHO);
  
  if (measurementReady == false) {
    if (ECHO == LOW and us_start_state == false){
      us_start = micros();
      us_start_state = true;
      us_end_state = false;
      digitalWrite(DO_LED, HIGH);
    } else if (ECHO == HIGH and us_end_state == false){
      measurementReady = true;
      us_end = micros();
      us_end_state = true;
      us_start_state = false;
    }
  }
}

//**************************************************************************************************
void oled_time_write(float timeDelta){
    int ezer = 0;
    float time =0.000;
  //Átszámítás
    if (timeDelta > 10000) {
      ezer = (timeDelta / 10000 );
      timeDelta = timeDelta - (ezer * 10000) ;
      time = 1 / float (timeDelta /10000);
    }
    else if (timeDelta > 1000){
      time = 1 / float (timeDelta /10000);
    }
    else if (timeDelta >= 10){
      time = 10000 * (1 / timeDelta);
    }
  float t = (ezer* 10000 + timeDelta) /10;

    // Kiírás oledre
    u8x8.setFont(u8x8_font_8x13B_1x2_f);
    u8x8.setCursor(0, 3);
    u8x8.print("Time:           ");
    u8x8.setCursor(5, 3);
    u8x8.print(t,1);
    u8x8.print(" ms");
    u8x8.setCursor(0, 6);
    u8x8.print("Expo:           ");
    u8x8.setCursor(5, 6);
    if (ezer >0) {
      u8x8.print(ezer);
      u8x8.print("+1/");
    }
    else {
      u8x8.print("1/"); 
    }
    u8x8.print(time, 1);
    u8x8.println(" s");


   //kiírás serila monitorra
    Serial.print("\t");
    Serial.print(t, 1);
    Serial.print("\t");
    Serial.print("\t");
    Serial.print(ezer);
    Serial.print("\t");
    Serial.println(time);
}

//**************************************************************************************************
void oled_default(void){
  u8x8.setFont(u8x8_font_pressstart2p_f);
  u8x8.clear();
  u8x8.drawString(0,0,"Shutter SPEED");
  u8x8.refreshDisplay();	
}
//**************************************************************************************************
void serial_default(){
    Serial.print("Time: ");
    Serial.print("\t");
    Serial.print("ms");
    Serial.print("\t");
    Serial.print("Time: " );
    Serial.print("\t");
    Serial.print("sec" );
    Serial.print("\t");
    Serial.println("+1/sec");
}