// Define pin connections
// Potentiometers
const int pot1Pin = A0;  // Controls brightness of LED1
const int pot2Pin = A1;  // Controls brightness of LED2
const int pot3Pin = A2;  // Controls the displayed number (0-99)

// LEDs
const int led1Pin = 3;   // LED1 (Even indicator)
const int led2Pin = 5;   // LED2 (Odd indicator)

// Shift Register 1 (for sevseg1, the tens digit)
const int sr1DataPin = 8;    // DS
const int sr1ClockPin = 9;   // SHCP
const int sr1LatchPin = 10;  // STCP

// Shift Register 2 (for sevseg2, the units digit)
const int sr2DataPin = 11;   // DS
const int sr2ClockPin = 12;  // SHCP
const int sr2LatchPin = 13;  // STCP

// 7-segment display segment patterns for common anode (0 is ON, 1 is OFF)
// Segments: A, B, C, D, E, F, G, DP
const byte segmentPatternsCommonAnode[] = {
  0b00000011,  // Digit 0
  0b10011111,  // Digit 1
  0b00100101,  // Digit 2
  0b00001101,  // Digit 3
  0b10011001,  // Digit 4
  0b01001001,  // Digit 5
  0b01000001,  // Digit 6
  0b00011111,  // Digit 7
  0b00000001,  // Digit 8
  0b00001001   // Digit 9
};

void setup() {
  // Initialize LED pins as outputs
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  
  // Initialize shift register pins as outputs
  pinMode(sr1DataPin, OUTPUT);
  pinMode(sr1ClockPin, OUTPUT);
  pinMode(sr1LatchPin, OUTPUT);
  pinMode(sr2DataPin, OUTPUT);
  pinMode(sr2ClockPin, OUTPUT);
  pinMode(sr2LatchPin, OUTPUT);
  
  // Turn off LEDs initially
  analogWrite(led1Pin, 0);
  analogWrite(led2Pin, 0);
  
  // Display "00" initially
  displayDigit(0, 1);  // Display 0 on the tens digit
  displayDigit(0, 2);  // Display 0 on the units digit
}

void loop() {
  // Read potentiometer values
  int pot1Value = analogRead(pot1Pin);  // Range: 0-1023
  int pot2Value = analogRead(pot2Pin);  // Range: 0-1023
  int pot3Value = analogRead(pot3Pin);  // Range: 0-1023
  
  // Map pot1 and pot2 values to PWM range (0-255) for LED brightness
  int led1Brightness = map(pot1Value, 0, 1023, 0, 255);
  int led2Brightness = map(pot2Value, 0, 1023, 0, 255);
  
  // Map pot3 value to a number range (0-99) for the 7-segment displays
  int displayNumber = map(pot3Value, 0, 1023, 0, 99);
  
  // Determine if the number is even or odd
  bool isEven = (displayNumber % 2 == 0);
  
  // Control LEDs based on whether the number is even or odd
  if (isEven) {
    analogWrite(led1Pin, led1Brightness);  // Turn on LED1 with adjustable brightness
    analogWrite(led2Pin, 0);               // Turn off LED2
  } else {
    analogWrite(led1Pin, 0);               // Turn off LED1
    analogWrite(led2Pin, led2Brightness);  // Turn on LED2 with adjustable brightness
  }
  
  // Extract the tens and units digits from the number
  int tensDigit = displayNumber / 10;
  int unitsDigit = displayNumber % 10;
  
  // Display the tens and units digits on the 7-segment displays
  displayDigit(tensDigit, 1);  // Display tens digit on sevseg1
  displayDigit(unitsDigit, 2);  // Display units digit on sevseg2
  
  // Add a small delay for stability
  delay(10);
}

// Function to display a digit on a specific 7-segment display
void displayDigit(int digit, int display) {
  // Ensure the digit is within the valid range
  if (digit < 0 || digit > 9) {
    digit = 0;  // Default to 0 for invalid digits
  }
  
  // Get the segment pattern for the digit
  byte segmentPattern = segmentPatternsCommonAnode[digit];
  
  // Send the segment pattern to the appropriate shift register
  if (display == 1) {
    // Display on sevseg1 (tens digit)
    digitalWrite(sr1LatchPin, LOW);  // Begin data transmission
    shiftOut(sr1DataPin, sr1ClockPin, MSBFIRST, segmentPattern);
    digitalWrite(sr1LatchPin, HIGH);  // Latch the data
  } else if (display == 2) {
    // Display on sevseg2 (units digit)
    digitalWrite(sr2LatchPin, LOW);  // Begin data transmission
    shiftOut(sr2DataPin, sr2ClockPin, MSBFIRST, segmentPattern);
    digitalWrite(sr2LatchPin, HIGH);  // Latch the data
  }
}