// Can you please check my code, when I press a button on IR remote I dont' get any serial print for the pressed key.
#include <IRremote.h>

int receiverPin = 11;        // Signal Pin of IR receiver to Arduino Digital Pin 11
const byte BUZZER_PIN = 12;  // Active buzzer


int latch = 9;   //74HC595  pin 9 STCP
int clock = 10;  //74HC595  pin 10 SHCP
int data = 8;    //74HC595  pin 8 DS

unsigned char table[] = { 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71, 0x00 };


/*-----( Declare objects )-----*/
// IRrecv receiver(receiverPin);  // create instance of 'irrecv'
//vairable uses to store the last decodedRawData
int last_decodedRawData = 0;

// --- IR Codes (Copied from Elegoo Code) ---
const int IR_1 = 48;   // Code for button 1
const int IR_2 = 24;   // Code for button 2
const int IR_3 = 122;  // Code for button 3
const int IR_4 = 16;   // Code for button 4
const int IR_5 = 56;   // Code for button 5
const int IR_6 = 90;   // Code for button 6
const int IR_7 = 66;   // Code for button 7
const int IR_8 = 74;   // Code for button 8
const int IR_9 = 82;   // Code for button 9
// For start/stop and reset if you want to use any other key then just replace the below code with the key you want to use.
const int IR_POWER = 162;  // Start / Stop
const int IR_RESET = 194;  // Reset

// --- Timer State ---
enum State { IDLE,
             RUNNING,
             FINISHED };
State state = IDLE;
byte timerValue = 0;  // 0 to 9
unsigned long lastSecond = 0;
int lastIRCode = 0;


void handleIR() {  // Function to handl IR input
  // int code = receiver.decodedIRData.command;
  int code = IrReceiver.decodedIRData.command;

  Serial.print("Received Button Code:");
  Serial.println(code);


  // Check if user press a button from 1-9 then set that as delay and set the state as IDLE
  if (code == IR_1) {
    timerValue = 1;
    state = IDLE;
  } else if (code == IR_2) {
    timerValue = 2;
    state = IDLE;
  } else if (code == IR_3) {
    timerValue = 3;
    state = IDLE;
  } else if (code == IR_4) {
    timerValue = 4;
    state = IDLE;
  } else if (code == IR_5) {
    timerValue = 5;
    state = IDLE;
  } else if (code == IR_6) {
    timerValue = 6;
    state = IDLE;
  } else if (code == IR_7) {
    timerValue = 7;
    state = IDLE;
  } else if (code == IR_8) {
    timerValue = 8;
    state = IDLE;
  } else if (code == IR_9) {
    timerValue = 9;
    state = IDLE;
  } else if (code == IR_POWER) {  // Check for Power button to pause/start the couting
    if ((state == IDLE || state == FINISHED) && timerValue > 0) {
      state = RUNNING;
    } else if (state == RUNNING) {
      state = IDLE;
    }
  } else if (code == IR_RESET) {
    timerValue = 0;
    state = IDLE;
    digitalWrite(BUZZER_PIN, LOW);  // ensure off
  }

  // receiver.resume();
}
void Display(unsigned char num) {
  digitalWrite(latch, LOW);
  shiftOut(data, clock, MSBFIRST, table[num]);
  digitalWrite(latch, HIGH);
}
void setup() {
  pinMode(latch, OUTPUT);
  pinMode(clock, OUTPUT);
  pinMode(data, OUTPUT);

  // Buzzer
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);

  Serial.begin(9600);
  Serial.println("IR Receiver Button Decode");
  // receiver.enableIRIn();  // Start the receiver
  IrReceiver.begin(receiverPin, ENABLE_LED_FEEDBACK);  // start receiver

  Display(0);                                          // Show digit 0 in the start
}

void loop() {
  // if (receiver.decode()) {
  //   handleIR();         // Keep checking IR handle function
  //   receiver.resume();  // Receive the next value
  // }
  if (IrReceiver.decode()) {
    handleIR();
    IrReceiver.resume();
  }
  // Update display
  if (state == RUNNING || state == IDLE || state == FINISHED) {
    Display(timerValue);
  }

  // Countdown logic
  if (state == RUNNING) {
    if (millis() - lastSecond >= 1000) {
      lastSecond = millis();
      if (timerValue > 0) {
        timerValue--;
        if (timerValue == 0) {
          state = FINISHED;
          digitalWrite(BUZZER_PIN, HIGH);
          // Buzzer will turn off after 1 second via delay (acceptable here)
          delay(1000);  // short blocking is OK for alert
          digitalWrite(BUZZER_PIN, LOW);
        }
      }
    }
  }
}