#include <Arduino.h>
#include <Servo.h>  // included as allowed even though not used in this project

// Define Arduino pins for sr1 (controls sevseg1)
const int sr1DS   = 2;   // data
const int sr1SHCP = 3;   // shift clock
const int sr1STCP = 4;   // storage clock (latch)

// Define Arduino pins for sr2 (controls sevseg2)
const int sr2DS   = 5;   // data
const int sr2SHCP = 6;   // shift clock
const int sr2STCP = 7;   // storage clock (latch)

// Define LED PWM pins
const int led1Pin = 10;
const int led2Pin = 11;

// Define potentiometer analog input pins
const int pot1Pin = A0;  // controls brightness for led1 (when active)
const int pot2Pin = A1;  // controls brightness for led2 (when active)
const int pot3Pin = A2;  // controls the number to be displayed (0-99)

// Segment patterns for digits 0-9 for common-anode 7-seg 
// (Bit order: DP, G, F, E, D, C, B, A; but we will send in order A, B, C, D, E, F, G, DP)
// In common-anode: a LOW (0) turns ON the segment.
const byte digitPatterns[10] = {
  0b11000000, // 0: A,B,C,D,E,F on, G off, DP off
  0b11111001, // 1: B,C on
  0b10100100, // 2
  0b10110000, // 3
  0b10011001, // 4
  0b10010010, // 5
  0b10000010, // 6
  0b11111000, // 7
  0b10000000, // 8
  0b10010000  // 9
};

void setup() {
  // Initialize shift register pins for sr1
  pinMode(sr1DS, OUTPUT);
  pinMode(sr1SHCP, OUTPUT);
  pinMode(sr1STCP, OUTPUT);
  
  // Initialize shift register pins for sr2
  pinMode(sr2DS, OUTPUT);
  pinMode(sr2SHCP, OUTPUT);
  pinMode(sr2STCP, OUTPUT);
  
  // Initialize LED pins
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  
  // Initialize potentiometer pins (handled by analogRead, no pinMode needed)

  // Initialize both 7-segment displays to show "00"
  // tens digit = 0 sent via sr1; units digit = 0 via sr2.
  updateShiftRegister(sr1DS, sr1SHCP, sr1STCP, digitPatterns[0]);
  updateShiftRegister(sr2DS, sr2SHCP, sr2STCP, digitPatterns[0]);
  
  // Turn off both LEDs initially
  analogWrite(led1Pin, 0);
  analogWrite(led2Pin, 0);
}

void loop() {
  // Read potentiometer values.
  int pot1Value = analogRead(pot1Pin);   // 0...1023 for LED1 brightness
  int pot2Value = analogRead(pot2Pin);   // 0...1023 for LED2 brightness
  int pot3Value = analogRead(pot3Pin);   // 0...1023 for display number
  
  // Map pot1 and pot2 values to PWM range (0-255)
  int brightness1 = map(pot1Value, 0, 1023, 0, 255);
  int brightness2 = map(pot2Value, 0, 1023, 0, 255);
  
  // Map pot3 value to a number from 0 to 99
  int number = map(pot3Value, 0, 1023, 0, 99);
  int tens = number / 10;
  int units = number % 10;
  
  // Even/Odd LED control:
  // If even, led1 is active (set to brightness1) and led2 off.
  // If odd, led1 off and led2 active (set to brightness2).
  if (number % 2 == 0) {
    analogWrite(led1Pin, brightness1);
    analogWrite(led2Pin, 0);
  } else {
    analogWrite(led1Pin, 0);
    analogWrite(led2Pin, brightness2);
  }
  
  // Update the 7-segment displays via the shift registers.
  // For sevseg1, send the tens digit pattern using sr1.
  updateShiftRegister(sr1DS, sr1SHCP, sr1STCP, digitPatterns[tens]);  
  // For sevseg2, send the units digit pattern using sr2.
  updateShiftRegister(sr2DS, sr2SHCP, sr2STCP, digitPatterns[units]);
  
  delay(50); // small delay to stabilize the readings and updates.
}

// A helper function to update a shift register.
// dataPin: DS pin; clockPin: SHCP; latchPin: STCP; data: byte to shift out.
void updateShiftRegister(int dataPin, int clockPin, int latchPin, byte data) {
  // Begin the latch so that outputs do not change until we finish shifting out data.
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, data);
  // Latch the data to the output pins.
  digitalWrite(latchPin, HIGH);
}