#include <FastLED.h>
#include <avr/pgmspace.h>

// ================= MATRIX CONFIG =================
#define LED_PIN 12
#define CHIPSET WS2812
#define COLOR_ORDER GRB
#define BRIGHTNESS 200

const uint8_t matrixWidth  = 32;
const uint8_t matrixHeight = 16;
#define NUM_LEDS (matrixWidth * matrixHeight)

CRGB leds[NUM_LEDS];

#define SERPENTINE true

// ================= CURRENT COLOR =================
CRGB currentColor = CRGB::Red;
bool rainbowMode = false;

// ================= SERIAL VARIABLES =================
String serialBuffer = "";

int countdownValue = 0;
bool countdownActive = false;
bool countdownPaused = false;

unsigned long lastUpdate = 0;

// ================= 5x7 FONT =================
const uint8_t font5x7[][5] PROGMEM = {
{62,81,73,69,62}, //0
{0,66,127,64,0},  //1
{98,81,73,73,70}, //2
{34,65,73,73,54}, //3
{24,20,18,127,16},//4
{39,69,69,69,57}, //5
{60,74,73,73,48}, //6
{1,113,9,5,3},    //7
{54,73,73,73,54}, //8
{6,73,73,41,30}   //9
};

// ================= XY FUNCTION =================
uint16_t XY(uint8_t x, uint8_t y)
{
  if (SERPENTINE && (y & 1))
    return (y * matrixWidth) + (matrixWidth - 1 - x);
  else
    return (y * matrixWidth) + x;
}

// ================= DRAW PIXEL =================
void drawPixel(int x,int y,CRGB color)
{
  if(x<0||y<0||x>=matrixWidth||y>=matrixHeight) return;
  leds[XY(x,y)] = color;
}

// ================= DRAW CHAR =================
void drawChar(int x,char c)
{
  if(c<'0'||c>'9') return;

  for(int col=0; col<5; col++)
  {
    uint8_t line = pgm_read_byte(&(font5x7[c-'0'][col]));

    for(int row=0; row<7; row++)
    {
      if(line & (1<<row))
        drawPixel(x+col,row+4,currentColor);
    }
  }
}

// ================= DISPLAY NUMBER =================
void displayNumber(int num)
{
  FastLED.clear();

  String s = String(num);
  int startX = (matrixWidth - s.length()*6)/2;

  for(int i=0;i<s.length();i++)
  drawChar(startX + i*6 , s[i]);

  FastLED.show();
}

// ================= DISPLAY TEXT =================
void displayText(String txt)
{
  FastLED.clear();

  int startX = (matrixWidth - txt.length()*6)/2;

  for(int i=0;i<txt.length();i++)
  drawChar(startX + i*6 , txt[i]);

  FastLED.show();
}

// ================= SCROLL TEXT =================
void scrollText(String txt)
{
  int width = txt.length()*6;

  for(int offset=matrixWidth; offset>-width; offset--)
  {
    FastLED.clear();

    for(int i=0;i<txt.length();i++)
    drawChar(offset + i*6 , txt[i]);

    FastLED.show();
    delay(80);
  }
}

// ================= RAINBOW EFFECT =================
void rainbowEffect()
{
  static uint8_t hue=0;

  for(int i=0;i<NUM_LEDS;i++)
  leds[i]=CHSV(hue+i*2,255,255);

  FastLED.show();
  hue++;
}

// ================= PROCESS COMMAND =================
void processCommand(String cmd)
{
  cmd.trim();
  cmd.toUpperCase();

  if(cmd=="HELP")
  {
    Serial.println("Commands:");
    Serial.println("MSG TEXT");
    Serial.println("SCROLL TEXT");
    Serial.println("NUMBER (example 60)");
    Serial.println("PAUSE");
    Serial.println("RESUME");
    Serial.println("STOP");
    Serial.println("COLOR R,G,B");
    Serial.println("RED GREEN BLUE YELLOW CYAN WHITE");
    Serial.println("RAINBOW");
  }

  else if(cmd.startsWith("MSG "))
  {
    String msg = cmd.substring(4);
    displayText(msg);
  }

  else if(cmd.startsWith("SCROLL "))
  {
    String msg = cmd.substring(7);
    scrollText(msg);
  }

  else if(cmd.startsWith("COLOR "))
  {
    int r,g,b;

    sscanf(cmd.c_str(),"COLOR %d,%d,%d",&r,&g,&b);

    currentColor = CRGB(r,g,b);
    rainbowMode=false;

    Serial.println("Color Updated");
  }

  else if(cmd=="RED"){currentColor=CRGB::Red;rainbowMode=false;}
  else if(cmd=="GREEN"){currentColor=CRGB::Green;rainbowMode=false;}
  else if(cmd=="BLUE"){currentColor=CRGB::Blue;rainbowMode=false;}
  else if(cmd=="YELLOW"){currentColor=CRGB::Yellow;rainbowMode=false;}
  else if(cmd=="CYAN"){currentColor=CRGB::Cyan;rainbowMode=false;}
  else if(cmd=="WHITE"){currentColor=CRGB::White;rainbowMode=false;}

  else if(cmd=="RAINBOW")
  {
    rainbowMode=true;
  }

  else if(cmd=="PAUSE")
  {
    countdownPaused=true;
  }

  else if(cmd=="RESUME")
  {
    countdownPaused=false;
  }

  else if(cmd=="STOP")
  {
    countdownActive=false;
    FastLED.clear();
    FastLED.show();
  }

  else
  {
    bool isNumber=true;

    for(int i=0;i<cmd.length();i++)
      if(!isDigit(cmd[i])) isNumber=false;

    if(isNumber)
    {
      countdownValue = cmd.toInt();
      countdownActive=true;
      countdownPaused=false;
      lastUpdate=millis();
      displayNumber(countdownValue);
    }
  }
}

// ================= SETUP =================
void setup()
{
  Serial.begin(9600);

  FastLED.addLeds<CHIPSET,LED_PIN,COLOR_ORDER>(leds,NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);

  FastLED.clear();
  FastLED.show();

  Serial.println("16x32 MATRIX READY");
  Serial.println("TYPE HELP");
}

// ================= LOOP =================
void loop()
{
  while(Serial.available())
  {
    char c = Serial.read();

    if(c=='\n'||c=='\r')
    {
      if(serialBuffer.length())
      {
        processCommand(serialBuffer);
        serialBuffer="";
      }
    }
    else
      serialBuffer+=c;
  }

  if(rainbowMode)
    rainbowEffect();

  if(countdownActive && !countdownPaused)
  {
    if(millis()-lastUpdate>=1000)
    {
      lastUpdate=millis();

      countdownValue--;

      if(countdownValue<=0)
      {
        countdownActive=false;
        displayText("DONE");
      }
      else
        displayNumber(countdownValue);
    }
  }
}