#include <avr/io.h>
#include <util/delay.h>

// Define macros for pin control
#define CLK_HIGH()  PORTB |= (1 << PB2)
#define CLK_LOW()   PORTB &= ~(1 << PB2)
#define CS_HIGH()   PORTB |= (1 << PB1)
#define CS_LOW()    PORTB &= ~(1 << PB1)
#define DATA_HIGH() PORTB |= (1 << PB0)
#define DATA_LOW()  PORTB &= ~(1 << PB0)
#define INIT_PORT() DDRB |= (1 << PB0) | (1 << PB1) | (1 << PB2)

// Flipped heart pattern
const uint8_t heart_frames[2][8] = 
{ 
    {
        0b00000000, 0b01100110, 0b10011001, 0b10000001,
        0b10000001, 0b01000010, 0b00100100, 0b00011000
    },
    {
        0b00000000, 0b00000000, 0b00100100, 0b01011010,
        0b01000010, 0b00100100, 0b00011000, 0b00000000
    }
};

uint8_t letter_V[8] = 
{
  0b11000011, 0b11000011, 0b11000011, 0b11000011,
  0b11100111, 0b01100110, 0b00111100, 0b00011000
};

uint8_t letter_A[8]=
{
    0b00011000, 0b01111110, 0b11100111, 0b11000011,
    0b11111111, 0b11111111, 0b11000011, 0b11000011
};

uint8_t letter_T[8]=
{
    0b11111111, 0b11111111, 0b00011000, 0b00011000,
    0b00011000, 0b00011000, 0b00011000, 0b00011000
};

uint8_t letter_L[8]=
{
    0b00000011, 0b00000011, 0b00000011, 0b00000011,
    0b00000011, 0b00000011, 0b11111111, 0b11111111
};

uint8_t letter_i[8]=
{
    0b00011000, 0b00011000, 0b00011000, 0b00011000,
    0b00011000, 0b00011000, 0b00011000, 0b00011000
};

uint8_t letter_I[8]=
{
  0b11111111, 0b11111111, 0b00011000, 0b00011000,
  0b00011000, 0b00011000, 0b11111111, 0b11111111
};

uint8_t letter_U[8]=
{
  0b11000011, 0b11000011, 0b11000011, 0b11000011,
  0b11000011, 0b11000011, 0b11111111, 0b11111111
};

uint8_t letter_S[8]=
{
  0b11111111, 0b11111111, 0b00000011, 0b11111111,
  0b11111111, 0b11000000, 0b11111111, 0b11111111
};

uint8_t letter_M[8]=
{
  0b11000011, 0b11100111, 0b11111111, 0b11011011,
  0b11011011, 0b11011011, 0b11011011, 0b11011011
};

uint8_t letter_E[8]=
{
    0b11111111, 0b11111111, 0b00000011, 0b11111111,
    0b11111111, 0b00000011, 0b11111111, 0b11111111
};

uint8_t letter_N[8]=
{
    0b11000011, 0b11000111, 0b11001111, 0b11011011,
    0b11110011, 0b11100011, 0b11100011, 0b11000011
};

uint8_t numeral_2[8] = 
{
  0b00111100, 0b01000010, 0b00100000, 0b00010000,
  0b00001000, 0b00000100, 0b00000010, 0b01111110
};

uint8_t numeral_0[8] = 
{
  0b00111100, 0b01000010, 0b01000010, 0b01000010,
  0b01000010, 0b01000010, 0b01000010, 0b00111100
};

uint8_t numeral_5[8] = 
{
  0b01111110, 0b00000010, 0b00000010, 0b00111110,
  0b01000000, 0b01000000, 0b01000000, 0b00111110
};

// Display buffer
uint8_t display[8];

// Function to send 8 bits of data via SPI
void spi_send(uint8_t data) {
  for (uint8_t i = 0; i < 8; i++, data <<= 1) {
    CLK_LOW();
    if (data & 0x80) {
      DATA_HIGH();
    } else {
      DATA_LOW();
    }
    CLK_HIGH();
  }
}

// Function to write to a specific MAX7219 register
void max7219_writec(uint8_t reg, uint8_t data) {
  CS_LOW();
  spi_send(reg);
  spi_send(data);
  CS_HIGH();
}

// Function to clear the MAX7219 display
void max7219_clear() {
  for (uint8_t i = 0; i < 8; i++) {
    max7219_writec(i + 1, 0);
  }
}

// Function to initialize the MAX7219
void max7219_init() {
  INIT_PORT();                // Set pins PB0, PB1, PB2 as output
  max7219_writec(0x09, 0x00); // Decode mode: none
  max7219_writec(0x0A, 0x03); // Intensity: low (0x00 to 0x0F)
  max7219_writec(0x0B, 0x07); // Scan limit: all rows
  max7219_writec(0x0C, 0x01); // Shutdown mode: off
  max7219_writec(0x0F, 0x00); // Display test: off
  max7219_clear();
}

void display_frame(const uint8_t* frame)
{
  for (uint8_t i=0;i<8;i++)
  {
    display[i]=frame[i];
    max7219_writec(i+1, display[i]);
  }
}

void bouncing_heart()
{
  for (uint8_t frame =0;frame <2; frame++)
  {
    display_frame(heart_frames[frame]);
    _delay_ms(500);
  }
  max7219_clear();
  // _delay_ms(500);// this line make the boucing animation have a blank
}
// Function to copy a pattern into the display buffer
void set_pixels(const uint8_t* pattern) {
  for (uint8_t i = 0; i < 8; i++) {
    display[i] = pattern[i];
  }
}

// Function to update the display with the buffer contents
void update_display() {
  for (uint8_t i = 0; i < 8; i++) {
    max7219_writec(i + 1, display[i]);
  }
}

// Function to display a single character
void display_character(const uint8_t* pattern) {
  set_pixels(pattern);  // Copy the character pattern into the display buffer
  update_display();     // Update the display
}

// Function to display the sequence "Valentine 2025"
void display_valentine() {
  // Define the sequence of characters for "Valentine 2025"
  const uint8_t* valentine[] = {
    letter_V, letter_A, letter_L, letter_E, letter_N,
    letter_T, letter_i, letter_N, letter_E,
    numeral_2, numeral_0, numeral_2, numeral_5
  };

  // Iterate over each character in the message
  for (uint8_t i = 0; i < sizeof(valentine) / sizeof(valentine[0]); i++) {
    display_character(valentine[i]);  // Display the character
    _delay_ms(500);                 // Wait 500ms before showing the next character
    max7219_clear();                // Clear the display for a clean transition             // Small delay before the next character
  }
}

void display_iusumi()
{
    const uint8_t* iusumi[] = 
    {
        letter_I, letter_U, letter_S, letter_U, letter_M, letter_I
    };

  // Iterate over each character in the message
  for (uint8_t i = 0; i < sizeof(iusumi) / sizeof(iusumi[0]); i++) 
  {
    display_character(iusumi[i]);  // Display the character
    _delay_ms(400);                 // Wait 500ms before showing the next character
    max7219_clear();                // Clear the display for a clean transition
  }
}

int main() {
  max7219_init();       // Initialize the MAX7219

  while (1) { 
    display_iusumi(); // Display "IU SUMI"
    _delay_ms(1000);
    display_valentine();  // Display "Valentine 2025"

    //Display heart bouncing in loop
    for (int i=0;i<50;i++)
    {
      bouncing_heart();
    }
    _delay_ms(1000);// Pause before repeating the message
  }

  return 0;
}