/*
 * 4-Digit 7-Segment Clock Display
 * Displays time in HH:MM format using TM1637 display module
 * Features: Clock display, adjustable time, blinking colon
 */

#include <TM1637Display.h>

// Pin definitions for TM1637
#define CLK_PIN 2    // Clock pin
#define DIO_PIN 3    // Data pin

// Button pins for setting time
#define HOUR_BTN 4   // Button to increment hours
#define MIN_BTN 5    // Button to increment minutes
#define SET_BTN 6    // Button to enter/exit set mode

// Create display object
TM1637Display display(CLK_PIN, DIO_PIN);

// Time variables
int hours = 12;
int minutes = 0;
int seconds = 0;

// State variables
bool setMode = false;           // Time setting mode flag
bool colonBlink = true;         // Colon blinking state
unsigned long lastUpdate = 0;   // Last time update timestamp
unsigned long lastBlink = 0;    // Last colon blink timestamp

// Button debouncing
unsigned long lastHourPress = 0;
unsigned long lastMinPress = 0;
unsigned long lastSetPress = 0;
const int debounceDelay = 200;

// Segment data for digits with colon
const uint8_t SEG_COLON = 0b01000000;  // Colon segment

void setup() {
  Serial.begin(9600);
  
  // Initialize button pins
  pinMode(HOUR_BTN, INPUT_PULLUP);
  pinMode(MIN_BTN, INPUT_PULLUP);
  pinMode(SET_BTN, INPUT_PULLUP);
  
  // Initialize display
  display.setBrightness(0x0f);  // Maximum brightness
  
  // Display startup message
  uint8_t data[] = {0x00, 0x00, 0x00, 0x00};
  display.setSegments(data);
  delay(500);
  
  Serial.println("4-Digit 7-Segment Clock Initialized");
  Serial.println("Use buttons to set time:");
  Serial.println("- SET button: Enter/Exit set mode");
  Serial.println("- HOUR button: Increment hours");
  Serial.println("- MIN button: Increment minutes");
}

void loop() {
  unsigned long currentMillis = millis();
  
  // Check button presses
  checkButtons();
  
  // Update seconds and time (only when not in set mode)
  if (!setMode && currentMillis - lastUpdate >= 1000) {
    lastUpdate = currentMillis;
    updateTime();
  }
  
  // Blink colon every 500ms
  if (currentMillis - lastBlink >= 500) {
    lastBlink = currentMillis;
    colonBlink = !colonBlink;
  }
  
  // Display time
  displayTime();
  
  delay(10);  // Small delay for stability
}

void updateTime() {
  seconds++;
  
  if (seconds >= 60) {
    seconds = 0;
    minutes++;
    
    if (minutes >= 60) {
      minutes = 0;
      hours++;
      
      if (hours >= 24) {
        hours = 0;
      }
    }
  }
  
  // Print to Serial Monitor
  Serial.print("Time: ");
  if (hours < 10) Serial.print("0");
  Serial.print(hours);
  Serial.print(":");
  if (minutes < 10) Serial.print("0");
  Serial.print(minutes);
  Serial.print(":");
  if (seconds < 10) Serial.print("0");
  Serial.println(seconds);
}

void displayTime() {
  // Create time display value
  int displayValue = hours * 100 + minutes;
  
  // Show time with or without colon based on blink state
  if (setMode) {
    // In set mode, always show colon
    display.showNumberDecEx(displayValue, 0b01000000, true);
  } else {
    // Normal mode, blink colon
    if (colonBlink) {
      display.showNumberDecEx(displayValue, 0b01000000, true);
    } else {
      display.showNumberDecEx(displayValue, 0b00000000, true);
    }
  }
}

void checkButtons() {
  unsigned long currentMillis = millis();
  
  // SET button - toggle set mode
  if (digitalRead(SET_BTN) == LOW && currentMillis - lastSetPress > debounceDelay) {
    lastSetPress = currentMillis;
    setMode = !setMode;
    
    if (setMode) {
      Serial.println("*** SET MODE ENABLED ***");
      Serial.println("Use HOUR and MIN buttons to adjust time");
    } else {
      Serial.println("*** SET MODE DISABLED ***");
      Serial.println("Time saved. Clock running.");
      seconds = 0;  // Reset seconds when exiting set mode
      lastUpdate = currentMillis;  // Reset update timer
    }
    
    delay(200);  // Additional debounce
  }
  
  // HOUR button - increment hours (only in set mode)
  if (setMode && digitalRead(HOUR_BTN) == LOW && currentMillis - lastHourPress > debounceDelay) {
    lastHourPress = currentMillis;
    hours++;
    if (hours >= 24) {
      hours = 0;
    }
    Serial.print("Hours set to: ");
    Serial.println(hours);
  }
  
  // MIN button - increment minutes (only in set mode)
  if (setMode && digitalRead(MIN_BTN) == LOW && currentMillis - lastMinPress > debounceDelay) {
    lastMinPress = currentMillis;
    minutes++;
    if (minutes >= 60) {
      minutes = 0;
    }
    Serial.print("Minutes set to: ");
    Serial.println(minutes);
  }
}