#include <M5Stack.h>
#define TFT_GREY 0x5AEB
uint32_t targetTime = 0;
static uint8_t conv2d(const char *p);
int  mm = 0, ss = 0;

byte omm = 99, oss = 99;
byte xcolon = 0, xsecs = 0;
bool run = false;
unsigned int colour = 0;

void setup(void)
{
    M5.begin();
    M5.Lcd.fillScreen(TFT_BLACK);
    M5.Lcd.setTextSize(1);
    M5.Lcd.setTextColor(TFT_YELLOW, TFT_BLACK);
    targetTime = millis() + 10;
}

void loop()
{
    if(M5.BtnA.wasPressed() && !run) mm++;
    if(M5.BtnB.wasPressed() && !run) ss++;
    if(M5.BtnC.wasPressed()) run = !run;
    if(M5.BtnC.pressedFor(5000))
    {
      mm = 0;
      ss = 0;
      run = false;
    }
    if(run)
    {
    if (targetTime < millis())
    {
        targetTime = millis() + 1000;
            ss--;
            if (ss == 0)
            {
                ss = 59;
                omm = mm;
                mm--;
                if (mm > 0)
                {
                    mm = 59;

                }
            }
        }
        int xpos = 0;
        int ypos = 85;
        int ysecs = ypos + 24;
        if (omm != mm)
        {
            omm = mm;

            if (mm < 10)
                xpos += M5.Lcd.drawChar('0', xpos, ypos, 7);
            xpos += M5.Lcd.drawNumber(mm, xpos, ypos, 7);
            xsecs = xpos;
        }
        if (oss != ss)
        {
            oss = ss;
            xpos = xsecs;
            if (ss % 2)
            {
                M5.Lcd.setTextColor(0x39C4, TFT_BLACK);
                M5.Lcd.drawChar(':', xcolon, ypos, 7);
                xpos += M5.Lcd.drawChar(':', xsecs, ypos, 7);
                M5.Lcd.setTextColor(TFT_YELLOW, TFT_BLACK);
            }
            else
            {
                M5.Lcd.drawChar(':', xcolon, ypos, 7);
                xpos += M5.Lcd.drawChar(':', xsecs, ypos, 7);
            }
            if (ss < 10)
                xpos += M5.Lcd.drawChar('0', xpos, ypos, 7);
           xpos += M5.Lcd.drawNumber(ss, xpos, ypos, 7);

        }
    }

    else
    {
      int xpos = 0;
      int ypos = 85;
            if (mm < 10)
                xpos += M5.Lcd.drawChar('0', xpos, ypos, 7);
            xpos += M5.Lcd.drawNumber(mm, xpos, ypos, 7);
            xsecs = xpos;
            xpos += M5.Lcd.drawChar(':', xsecs, ypos, 7);
             if (ss < 10)
                xpos += M5.Lcd.drawChar('0', xpos, ypos, 7);
           xpos += M5.Lcd.drawNumber(ss, xpos, ypos, 7);
    }

    M5.update();
}