// update min hand every 15 sec, correct for step calc rounding errors every hour.
#include <Button2.h>
#include <Encoder.h>
#include <RTClib.h>;
RTC_DS3231 rtc;
// SDA to A4, CLK to A5, VCC to 5V

// Motor and clock parameters
const long STEPS_PER_REV = 4096;  //64 STEPS PER MOTOR REV * 64:1 GEAR RATIO
/*
    4096 *1/60 hr to min * 1/60 min to sec = 1.3777 steps/sec
    15 sec * 1.377777 = 17.06666 steps.  Use 17 steps every 15 sec.
    .066666*4*60 = 16 step undershoot per hour.
*/

//#define STEPS_PER_REV 4096 // steps of a single rotation of motor
//#define RATIO 15 // minutes per a rotation

#define BUTTON_PIN 12
Button2 button;

// wait for a single step of stepper
int delaytime = 2;

// ports used to control the stepper motor
// if your motor rotate to the opposite direction,
// 7 to IN1, 6 to IN2, 5 to IN3, 4 to IN5
// change the order as {4, 5, 6, 7};
int port[4] = { 7, 6, 5, 4 };

// sequence of stepper motor control
int seq[8][4] = {
  { LOW, HIGH, HIGH, LOW },
  { LOW, LOW, HIGH, LOW },
  { LOW, LOW, HIGH, HIGH },
  { LOW, LOW, LOW, HIGH },
  { HIGH, LOW, LOW, HIGH },
  { HIGH, LOW, LOW, LOW },
  { HIGH, HIGH, LOW, LOW },
  { LOW, HIGH, LOW, LOW }
};

void rotate(int step) {
  static int phase = 0;
  int i, j;
  int delta = (step > 0) ? 1 : 7;

  step = (step > 0) ? step : -step;
  for (j = 0; j < step; j++) {
    phase = (phase + delta) % 8;
    for (i = 0; i < 4; i++) {
      digitalWrite(port[i], seq[phase][i]);
    }
    delay(delaytime);
  }
  // power cut
  for (i = 0; i < 4; i++) {
    digitalWrite(port[i], LOW);
  }
}

#define ENCODER_CLK 2
#define ENCODER_DT  3
Encoder myEnc(ENCODER_CLK, ENCODER_DT);

void pressed(Button2& btn) {
  while (digitalRead(12) == LOW) {
    delaytime = 2;
    rotate(-68);
  }
  delaytime = 10;
}

int prevMin = 0;
int thisMin = 0;
int thisSec = 0;
int prevSec = 0;
int thisHr = 0;
int prevHr = 0;

DateTime now;

void setup() {
  Serial.begin(9600);

  pinMode(port[0], OUTPUT);
  pinMode(port[1], OUTPUT);
  pinMode(port[2], OUTPUT);
  pinMode(port[3], OUTPUT);
  pinMode(14, OUTPUT);
  digitalWrite(14, LOW);
  pinMode(16, INPUT_PULLUP);


  if (!rtc.begin()) {
    Serial.println(F("Couldn't find RTC"));
    while (1)
      ;
  }

  button.begin(BUTTON_PIN);
  button.setPressedHandler(pressed);

  // following line sets the RTC to the date & time this sketch was compiled
  //rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));  //uncomment to set time, then recomment and reupload
  //rtc.adjust(DateTime(2023, 8, 16, 0, 15, 0)); // YYY, MM, DD, HH, MM, SS

  now = rtc.now();

  Serial.print(now.hour());
  Serial.println(" hr");
  Serial.print(now.minute());
  Serial.println(" min");

  prevSec = now.second();
  thisSec = prevSec;

  prevMin = now.minute();
  thisMin = prevMin;

  prevHr = now.hour();
  thisHr = prevHr;

  int delaytime = 10;
}

int interval = 1000;
unsigned long lastmilli = 0;
long steps = 0;
int incr = 0;
long oldPosition  = -999;  // set encoder initial position
int elapseSec = 0;

void loop() {
  unsigned long thismilli = millis();
  button.loop();

  if (thismilli - lastmilli > interval) {
    lastmilli = thismilli;
    now = rtc.now();
    thisSec = now.second();
    thisMin = now.minute();
    thisHr = now.hour();
    //Serial.print(thisMin); Serial.println(" thisMin");

    // update min hand every 15 sec
    if (thisSec != prevSec) {
      elapseSec++;
      prevSec = thisSec;
      if (elapseSec % 15 == 0) {
        rotate(17);  //assume direct 1:1 gearing between stepper output shaft and min hand
        Serial.print("elapseSec: "); Serial.println(elapseSec);
        if (elapseSec >= 15) elapseSec = 0;
      }
    }

  }

  // catch up step count each hour
  if (thisHr != prevHr) {
    prevHr = thisHr;
    rotate(16); //correct cumulative step error

  }
  
  /*  Add a daylight saving automatic adjuster
   *   https://www.instructables.com/The-Arduino-and-Daylight-Saving-Time-Europe/
   *   The EU has a guideline that determines the daylight saving time to start on the last Sunday of March and to end on the last Sunday of October. 
   *   The USA has daylight saving time from the 2nd Sunday of March till the first Sunday of November.
   *   Daylight Saving Time (DST) in most of the United States starts on the second Sunday in March and ends on the first Sunday in November.
   *   EU
   *   Start      
            if (dow == 7 && mo == 3 && d >= 25 && h ==2 && DST==0)
        
            {
        
            setclockto 3 am;
        
            DST=1; //store this in your NVRAM
        
            }
   *   End
            if (dow == 7 && mo == 10 && d >= 25 && h == 3 && DST==1)
        
            {
        
            setclockto 2 am;
        
            DST=0;//store this in your NVRAM
        
            }

  *   US
  *   
  */


  // if (thisMin != prevMin) {
  //   prevMin = thisMin;
  //   Serial.print(thisMin);
  //   Serial.println(" mins");
  //   // if stepper to min hand is 1:1 then each min = 68.26666... steps (4096/60).
  //   // therefore move 68 steps each time, then on the 15th time, move an extra 4 steps (15*.2666666)
  //   if (thisMin % 15 == 0) {
  //     incr = 72;
  //   } else {
  //     incr = 68;
  //   }
  //   Serial.print(incr);
  //   Serial.println(" incr");

  //   rotate(incr);

  //   steps += incr;
  //   Serial.print(steps);
  //   Serial.println(" steps");

  //   Serial.println();

  //   // if stepper to min hand has a 4:1 ratio (4 stepper motor rotor rotations per 1 min increment) then
  //   // each 1 min tick would require 68.266666 * 4 steps = 273.0666666... steps.  So a correction of 4 steps would
  //   // be needed at each full rotation (1 hr | .06666 * 60 = 4) instead of each 15 min.
  // }

  //read Encoder
  long newPosition = myEnc.read() / 4;
  if (newPosition != oldPosition) {
    if (newPosition > oldPosition) {
      //clockwise
      delaytime = 2;
      rotate(-68);
      delaytime = 10;
    } else {
      //anti-clockwise
      delaytime = 2;
      rotate(68);
      delaytime = 10;
    }
    oldPosition = newPosition;
  }
}