#include <ShiftRegister74HC595.h>
#include <RTClib.h> // Include the RTClib library for DS1307 RTC

// Define the pin for the mode button
#define MODE_BUTTON_PIN 10 // Example pin number, replace with your actual pin

// Shift register Pin definitions
#define DS_PIN 4    // DS - Pin 04
#define STCP_PIN 3  // STCP - PIN 03
#define SHCP_PIN 2  // SHCP - PIN 02

// Create instances of ShiftRegister74HC595 for each shift register with size
ShiftRegister74HC595<24> sr(DS_PIN, SHCP_PIN, STCP_PIN);

// Pin Definitions for 4-digit 7-segment display
const int segDataLine1[4] = {14, 15, 16, 17}; // First 4-Digit 7-Segment Display (Display 1). Pins for each digit (D1-D4)
const int segDataLine2[4] = {18, 19, 20, 21}; // Second 4-Digit 7-Segment Display (Display 2). Pins for each digit (D1-D4)

// Digit patterns for common cathode display (with decimal points)
const byte digitPatterns[10] = {
  B00111111, // Digit 0
  B00000110, // Digit 1
  B01011011, // Digit 2
  B01001111, // Digit 3
  B01100110, // Digit 4
  B01101101, // Digit 5
  B01111101, // Digit 6
  B00000111, // Digit 7
  B01111111, // Digit 8
  B01101111  // Digit 9
};

// Define segment mapping for each display
int segMapDisplay1[7] = {0, 1, 2, 3, 4, 5, 6};    // A-G Segment mapping for Display 1
int segMapDisplay2[7] = {7, 8, 9, 10, 11, 12, 13}; // A-G Segment mapping for Display 2
int segDecimalPoints[7] = {22, 23};               // Segment mapping for Decimal Point

RTC_DS1307 rtc; // Real Time Clock using RTC_DS1307 library

void setup() {
  // Initialize shift register pins as outputs
  for (int i = 0; i < 4; i++) {
    pinMode(segDataLine1[i], OUTPUT);
    pinMode(segDataLine2[i], OUTPUT);
  }

  // Initialize the RTC
  rtc.begin();

  // If the RTC isn't running, set the time and date manually
  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(2024, 3, 24, 10, 0, 0)); // Set RTC to 03/24/2024 10:00:00
  }
}

void loop() {
  displayTimeOrDate(); // Display time or date based on mode button
}

void displayTimeOrDate() {
  DateTime now = rtc.now(); // Get current date and time from RTC

  if (digitalRead(MODE_BUTTON_PIN) == HIGH) { // Check if mode button is pressed
    displayTime(now); // Display current time
  } else {
    displayDate(now); // Display current date
  }

  delay(1000); // Delay for 1 second
}

void displayTime(DateTime time) {
  byte hour = time.hour();
  byte minute = time.minute();
  byte second = time.second();

  displayNumber(hour / 10, segDataLine1); // Display hour tens digit on first display
  displayNumber(hour % 10, segDataLine2); // Display hour ones digit on second display
  delay(5); // Delay for multiplexing effect
  displayNumber(minute / 10, segDataLine1); // Display minute tens digit on first display
  displayNumber(minute % 10, segDataLine2); // Display minute ones digit on second display
  delay(5); // Delay for multiplexing effect
  displayNumber(second / 10, segDataLine1); // Display second tens digit on first display
  displayNumber(second % 10, segDataLine2); // Display second ones digit on second display
}

void displayDate(DateTime time) {
  byte month = time.month();
  byte day = time.day();
  int year = time.year();

  displayNumber(month / 10, segDataLine1); // Display month tens digit on first display
  displayNumber(month % 10, segDataLine2); // Display month ones digit on second display
  delay(5); // Delay for multiplexing effect
  displayNumber(day / 10, segDataLine1); // Display day tens digit on first display
  displayNumber(day % 10, segDataLine2); // Display day ones digit on second display
  delay(5); // Delay for multiplexing effect
  displayNumber(year / 1000, segDataLine1); // Display year thousands digit on first display
  displayNumber((year % 1000) / 100, segDataLine2); // Display year hundreds digit on second display
}

void displayNumber(int number, const int* segDataLine) {
  byte pattern = digitPatterns[number];
  sr.setAllLow(); // Set all segments to low initially (turn off)

  // Set the segments according to the pattern
  for (int i = 0; i < 7; i++) {
    sr.set(segMapDisplay1[i], bitRead(pattern, i));
    sr.set(segMapDisplay2[i], bitRead(pattern, i));
  }

  // Output the pattern to the corresponding display's segment lines
  for (int i = 0; i < 4; i++) {
    digitalWrite(segDataLine[i], bitRead(pattern, i));
  }

  sr.updateRegisters(); // Update the shift registers with the new data
}