#include <avr/io.h>
#include <avr/interrupt.h>

// Constants for button debounce
#define DEBOUNCE_TIME 5 // in milliseconds

volatile int dutyCycle = 0; // Duty cycle of PWM (0-255)
volatile bool updateDisplay = false; // Flag to update 7-segment display

const uint8_t segmentMap[10] = {
  0b00111111, // 0
  0b00000110, // 1
  0b01011011, // 2
  0b01001111, // 3
  0b01100110, // 4
  0b01101101, // 5
  0b01111101, // 6
  0b00000111, // 7
  0b01111111, // 8
  0b01101111  // 9
};

// Initialize PWM on pin D9
void initPWM() {
  pinMode(9, OUTPUT);
  TCCR1A = (1 << WGM10) | (1 << COM1A1);
  TCCR1B = (1 << CS11) | (1 << CS10); // Prescaler 64
  OCR1A = 0; // Initial duty cycle
}

// Initialize interrupts for buttons
void initInterrupts() {
  EICRA = (1 << ISC01) | (1 << ISC00) | (1 << ISC11) | (1 << ISC10); // Rising edge for INT0 and INT1
  EIMSK = (1 << INT0) | (1 << INT1); // Enable INT0 and INT1
  sei(); // Enable global interrupts
}

// Update 7-segment display
void update7SegmentDisplay(int value) {
  PORTD = segmentMap[value % 10]; // Display single digit 0-9
}

// Interrupt Service Routine for INT0
ISR(INT0_vect) {
  static unsigned long lastInterruptTime0 = 0;
  unsigned long interruptTime = millis();
  if (interruptTime - lastInterruptTime0 > DEBOUNCE_TIME) {
    if (dutyCycle < 255) dutyCycle += 28;
    if (dutyCycle > 255) dutyCycle = 255;
    OCR1A = dutyCycle;
    updateDisplay = true;
    lastInterruptTime0 = interruptTime;
  }
}

// Interrupt Service Routine for INT1
ISR(INT1_vect) {
  static unsigned long lastInterruptTime1 = 0;
  unsigned long interruptTime = millis();
  if (interruptTime - lastInterruptTime1 > DEBOUNCE_TIME) {
    if (dutyCycle > 0) dutyCycle -= 28;
    if (dutyCycle < 0) dutyCycle = 0;
    OCR1A = dutyCycle;
    updateDisplay = true;
    lastInterruptTime1 = interruptTime;
  }
}

void setup() {
  // Set up 7-segment display pins
  DDRD = 0xFF; // Set PORTD as output for 7-segment display
  
  initPWM();
  initInterrupts();
}

void loop() {
  if (updateDisplay) {
    update7SegmentDisplay(dutyCycle / 28); // Display the step 0-9
    updateDisplay = false;
  }
}






// #include <avr/io.h>
// #include <util/delay>
// #include <avr/interrupt.h>











// #include <avr/io.h>
// // #include <LiquidCrystal_I2C.h>

// // LiquidCrystal_I2C lcd(0x27, 16, 2);


// ISR(PCINT2_vect) {
//   //inputs are active low
//   uint8_t pd = ~PIND;
//   if (pd & 0x80)//we need to determine which pin generated interrupt
//     PORTB |= 1 << PB1;
//   else if (pd & 0x40)
//     PORTB &= ~(1 << PB1);
// }

// float read_adc() {
//   ADCSRA |= (1 << ADSC);            // Start the Conversion
//   while (ADCSRA & (1 << ADSC));     // Wait for Conversion to Complete
//   uint16_t adcValue = ADC;          // Read the ADC Value
//   int brightness = adcValue / (1023 / 9);
//   return brightness;
// }

// volatile float brightness = 0.0;

// volatile int state=LOW;
// byte bit5;

// void print_brightness() {

// }

// void setup() {
//     // PORTD = 1 << PD2;//interal pull up
//     // brightness = read_adc();
//     // print_brightness();

//     DDRD &= ~((1 << PD7) |  (1 << PD6)) ;//port D as input
//     PORTD = (1 << PD7) | (1 << PD6);//use pull up resistors PORTD6 and 7
//     DDRB= 1 << PB1;//output port bit
//     PORTD = 0x04;//configure to use pull up resistor
//   /* set PORTB BIT IN PIN 13 as output */
//     DDRB |= 0x20;// DDRB5 pin 13 as output
//     // Enable pin change interrupts
//     PCICR = 1 << PCIE2;                       //enable pin change interrupt bank 2
//     PCMSK2 = (1 << PCINT22) | (1 << PCINT23); //enable pin change interrupt on PCINT22 PCINT23
//     sei();// Set global interrupt flag
// }

// int main() {
//     init();
//     setup();
//     // while(true) {
//     //   float new_brightness = read_adc();
//     //   if (new_brightness != brightness) {
//     //     brightness = new_brightness;
//     //     print_brightness();
//     //   }
//     // }

//   // DDRD = 0x40; //PORTD bit 2 as input
  
//   EIMSK |= 0b00000001;//Enable ext interrupt INT0
//   EICRA |= 0b00000010;//Trig. INT0 on falling edge
//   bit5 = 1 << 5;//set bit 5 to 1 shifting 5 times
//   sei();//Enable interrupts
//   while (true) {
//       PORTB = state;//change state
//   }
// }