#include <Wire.h>
#include <LiquidCrystal.h>

// LCD pins
const int lcdRS = PB0;
const int lcdEN = PB1;
const int lcdD4 = PB10;
const int lcdD5 = PB11;
const int lcdD6 = PA8;
const int lcdD7 = PA9;
LiquidCrystal lcd(lcdRS, lcdEN, lcdD4, lcdD5, lcdD6, lcdD7);

// MAX7219 pins
#define DIN_PIN PA7
#define CLK_PIN PA6
#define CS_PIN  PA5

// Pushbutton and LEDs pins
#define BTN1_PIN PB0
#define BTN2_PIN PB1
#define LED1_PIN PB10
#define LED2_PIN PB11

unsigned long previousMillis = 0;
const unsigned long interval = 1000; // 1 second

int seconds = 0;
int minutes = 49;
int hours = 21;
int dayOfMonth = 9;
int month = 8;
int year = 2025;
int weekdays = 6; // Saturday

unsigned long patternStartMillis = 0;
bool patternActive = false;

const unsigned long patternDuration = 5000; // total pattern active duration (5 sec)

// 8x8 font for digits 0-9 (simple) - not used here but kept if needed later
const byte digits[10][8] = {
  {0x3C,0x66,0x6E,0x7E,0x76,0x66,0x3C,0x00}, //0
  {0x18,0x38,0x18,0x18,0x18,0x18,0x7E,0x00}, //1
  {0x3C,0x66,0x06,0x1C,0x30,0x66,0x7E,0x00}, //2
  {0x3C,0x66,0x06,0x1C,0x06,0x66,0x3C,0x00}, //3
  {0x0C,0x1C,0x3C,0x6C,0x7E,0x0C,0x1E,0x00}, //4
  {0x7E,0x60,0x7C,0x06,0x06,0x66,0x3C,0x00}, //5
  {0x1C,0x30,0x60,0x7C,0x66,0x66,0x3C,0x00}, //6
  {0x7E,0x06,0x0C,0x18,0x18,0x18,0x18,0x00}, //7
  {0x3C,0x66,0x3C,0x66,0x66,0x66,0x3C,0x00}, //8
  {0x3C,0x66,0x66,0x3E,0x06,0x0C,0x38,0x00}  //9
};

void spiTransfer(byte data) {
  for (int i = 7; i >= 0; i--) {
    digitalWrite(CLK_PIN, LOW);
    digitalWrite(DIN_PIN, (data & (1 << i)) ? HIGH : LOW);
    digitalWrite(CLK_PIN, HIGH);
  }
}

void max7219Write(byte address, byte data) {
  digitalWrite(CS_PIN, LOW);
  for (int i = 0; i < 4; i++) {
    spiTransfer(address);
    spiTransfer(data);
  }
  digitalWrite(CS_PIN, HIGH);
}

void max7219Init() {
  pinMode(DIN_PIN, OUTPUT);
  pinMode(CLK_PIN, OUTPUT);
  pinMode(CS_PIN, OUTPUT);

  max7219Write(0x0C, 0x01); // Shutdown: Normal operation
  max7219Write(0x09, 0x00); // Decode mode: none (raw data)
  max7219Write(0x0B, 0x07); // Scan limit: all digits
  max7219Write(0x0A, 0x08); // Intensity: medium
  max7219Write(0x0F, 0x00); // Display test: off

  clearMatrix();
}

void clearMatrix() {
  for (byte i = 1; i <= 8; i++) {
    max7219Write(i, 0);
  }
}

void showPattern() {
  for (byte i = 1; i <= 8; i++) {
    max7219Write(i, 0xFF);
  }
}

void setup() {
  Serial.begin(115200);
  Wire.begin(PB7, PB6);

  pinMode(BTN1_PIN, INPUT_PULLUP);
  pinMode(BTN2_PIN, INPUT_PULLUP);
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);

  lcd.begin(16, 2);
  lcd.print("Starting...");

  max7219Init();

  delay(2000);
  lcd.clear();
}

void loop() {
  unsigned long currentMillis = millis();

  // Update time every second
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    seconds++;
    if (seconds >= 60) {
      seconds = 0;
      minutes++;
    }
    if (minutes >= 60) {
      minutes = 0;
      hours++;
    }
    if (hours >= 24) {
      hours = 0;
      dayOfMonth++;
      weekdays++;
      if (weekdays > 7) weekdays = 1;
      // skipping month/year update for simplicity
    }
  }

  bool btn1Pressed = (digitalRead(BTN1_PIN) == LOW);
  bool btn2Pressed = (digitalRead(BTN2_PIN) == LOW);

  // If BTN1 pressed: show pattern
  if (btn1Pressed && !patternActive) {
    patternActive = true;
    patternStartMillis = currentMillis;
    digitalWrite(LED1_PIN, HIGH);
    digitalWrite(LED2_PIN, LOW);
    lcd.clear(); // clear LCD when pattern starts
  }

  // If BTN2 pressed: clear pattern immediately
  if (btn2Pressed && patternActive) {
    patternActive = false;
    clearMatrix();
    digitalWrite(LED1_PIN, LOW);
    digitalWrite(LED2_PIN, HIGH);
    delay(200); // brief LED indication
    digitalWrite(LED2_PIN, LOW);
  }

  if (patternActive) {
    if (currentMillis - patternStartMillis < patternDuration) {
      showPattern();   // Keep showing the pattern continuously
    } else {
      // pattern time ended, clear pattern & deactivate
      patternActive = false;
      clearMatrix();
      digitalWrite(LED1_PIN, LOW);
      digitalWrite(LED2_PIN, LOW);
    }
  } else {
    clearMatrix(); // keep matrix blank if no pattern
  }

  // Show time/date on LCD only if pattern not active
  if (!patternActive) {
    lcd.setCursor(0, 0);
    lcd.print("Time: ");
    if (hours < 10) lcd.print('0');
    lcd.print(hours);
    lcd.print(':');
    if (minutes < 10) lcd.print('0');
    lcd.print(minutes);
    lcd.print(':');
    if (seconds < 10) lcd.print('0');
    lcd.print(seconds);

    lcd.setCursor(0, 1);
    lcd.print("Date: ");
    if (dayOfMonth < 10) lcd.print('0');
    lcd.print(dayOfMonth);
    lcd.print('/');
    if (month < 10) lcd.print('0');
    lcd.print(month);
    lcd.print('/');
    lcd.print(year);
  }

  delay(50);
}