#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <DHT.h>
#include <SPI.h>
#include <Wire.h>
#include "Font7Seg.h"

#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define CLK_PIN    13
#define DATA_PIN   11
#define CS_PIN     10
#define SPEED_TIME 100   
#define PAUSE_TIME 3000  
#define MAX_MESG   20

#define DS1307_ADDRESS 0x68
#define DHTPIN 2
#define DHTTYPE DHT22
#define TIMEDHT 2000 

uint8_t hours, minutes, seconds;
char szTime[9];    
char szMesg[MAX_MESG + 1] = "";
float celsius;
uint32_t timerDHT = 0;
uint32_t timerSerial = 0;

DHT dht(DHTPIN, DHTTYPE);

MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

void beginDS1307()
{
  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(0x00);
  Wire.endTransmission();
  Wire.requestFrom(DS1307_ADDRESS, 7);

  seconds = bcdToDec(Wire.read());
  minutes = bcdToDec(Wire.read());
  hours = bcdToDec(Wire.read() & 0x3f);
}

uint8_t decToBcd(uint8_t value)
{
  return ((value / 10 * 16) + (value % 10));
}

uint8_t bcdToDec(uint8_t value)
{
  return ((value / 16 * 10) + (value % 16));
}

void getTime(char *psz)
{
  sprintf(psz, "%02d:%02d", hours, minutes);
}

void getTemperature()
{
  if ((millis() - timerDHT) > TIMEDHT) {
    timerDHT = millis();
    celsius = dht.readTemperature();
  }
}

uint16_t calculateChecksum(const char* str)
{
  uint16_t checksum = 0;
  while (*str)
  {
    checksum += *str++;
  }
  return checksum;
}

void setup(void)
{
  Wire.begin();
  Serial.begin(9600);  
  P.begin();
  P.setInvert(false);

  P.setZone(0,  MAX_DEVICES - 4, MAX_DEVICES - 1);
  P.setZone(1, MAX_DEVICES - 4, MAX_DEVICES - 1);

  P.displayZoneText(1, szTime, PA_CENTER, SPEED_TIME, PAUSE_TIME, PA_PRINT, PA_NO_EFFECT);
  P.displayZoneText(0, szMesg, PA_CENTER, SPEED_TIME, PAUSE_TIME, PA_PRINT , PA_NO_EFFECT);

  dht.begin();
}

void loop(void)
{
  static uint32_t lastTime = 0;
  static uint8_t  display = 0;

  beginDS1307();
  getTemperature();

  P.displayAnimate();

  if (P.getZoneStatus(0))
  {
    switch (display)
    {
      case 0: 
        P.setPause(0, PAUSE_TIME);
        P.setTextEffect(0, PA_SCROLL_UP, PA_SCROLL_UP); 
        display++;
        dtostrf(celsius, 4, 1, szMesg); 
        strcat(szMesg, "C");
        break;

      case 1: 
        P.setFont(0, numeric7Seg);
        P.setTextEffect(0, PA_SCROLL_UP, PA_SCROLL_UP); 
        P.setPause(0, PAUSE_TIME);

        if ((millis() - lastTime) >= 1000) {
          lastTime = millis();
          getTime(szMesg);
        }
        display = 0; 
        break;
    }

    P.displayReset(0);
  }

  if (millis() - timerSerial >= 1000) 
  {
    timerSerial = millis();
    char serialMsg[20];
    sprintf(serialMsg, ">%02d:%02d+%.1fC<", hours, minutes, celsius);
    uint16_t checksum = calculateChecksum(serialMsg);
    Serial.print(serialMsg);
    Serial.print(" Checksum: ");
    Serial.println(checksum);
  }
}