#include <Wire.h>
#include <RTClib.h>

// ─── MOTOR CONFIG ──────────────────────────────────────────────────────
// Your 20-step motor at 2× microstep → 40 steps/rev:
#define FULL_STEPS       20
#define MS2_STEPS_DIG    2
#define STEPS_REV_DIG    (FULL_STEPS * MS2_STEPS_DIG) // 40

// For digits 0–9: 4 steps per flap
#define STEPS_PER_DIGIT  1 //(STEPS_REV_DIG / 10)        // 4

// A/P and M-letter spools: 2 states → half-rev
#define STEPS_AP_M       1 //(STEPS_REV_DIG / 2)         // 20

// Weekday spool at 4× microstep → 80 steps/rev
#define MS2_STEPS_WD     4
#define STEPS_REV_WD     (FULL_STEPS * MS2_STEPS_WD) // 80
#define STEPS_PER_DAY    ((STEPS_REV_WD + 3) / 7)    // round(80/7)=11

// ─── PIN ASSIGNMENTS ────────────────────────────────────────────────────
// Indices: 0=H10,1=H1,2=M10,3=M1,4=AP,5=Mchar,6=WD
//const uint8_t MS1_PINS[7]  = { 2,  6, 10, 14, 18, 22, 26};
//const uint8_t MS2_PINS[7]  = { 3,  7, 11, 15, 19, 23, 27};
//const uint8_t DIR_PINS[7]  = { 4,  5,  8,  9, 12, 13, 25};
const uint8_t STEP_PINS[7] = {7, 6, 5, 4, 3, 2, 8};

// Track current states:
uint8_t currentState[7] = {0};

// RTC
RTC_DS3231 rtc;

void setup(){
  Serial.begin(115200);
  Wire.begin();
  initRTC();

  // Initialize all steppers
  for(uint8_t i=0; i<7; i++){
    //pinMode(MS1_PINS[i], OUTPUT);
    //pinMode(MS2_PINS[i], OUTPUT);
    //pinMode(DIR_PINS[i], OUTPUT);
    pinMode(STEP_PINS[i], OUTPUT);

    // Set microstep mode:
    if(i < 6){
      // Digit, A/P, Mchar → 2× microstep
      digitalWrite(MS1_PINS[i], HIGH);
      digitalWrite(MS2_PINS[i], LOW);
    } else {
      // Weekday → 4× microstep
      digitalWrite(MS1_PINS[i], LOW);
      digitalWrite(MS2_PINS[i], HIGH);
    }
    // Always forward
    digitalWrite(DIR_PINS[i], HIGH);
    digitalWrite(STEP_PINS[i], LOW);
  }
}

void loop(){
  DateTime now = rtc.now();

  // Convert to 12-hour + AM/PM
  uint8_t h12 = now.twelveHour(); //% 12;   // 0–11
  bool isPM  = now.isPM();
  uint8_t m  = now.minute();             // 0–59
  uint8_t wd = now.dayOfTheWeek();       // 0=Sun..6=Sat

  // Build targets
  uint8_t target[7];
  target[0] = h12 / 10;     // H10 (0 or 1)
  target[1] = h12 % 10;     // H1  (0–9)
  target[2] = m   / 10;     // M10 (0–5)
  target[3] = m   % 10;     // M1  (0–9)
  target[4] = isPM ? 1 : 0; // A/P spool: 0=A, 1=P
  target[5] = isPM ? 1 : 0; // M-letter spool: 0=blank, 1=M
  target[6] = wd;           // Weekday 0–6

  // Step each forward-only to its new position
  for(uint8_t i=0; i<7; i++){
    uint16_t newStep = computeStepCount(i, target[i]);
    stepForward(i, newStep);
    currentState[i] = target[i];
  }

  delay(1000);
}

// ─── RTC INIT ───────────────────────────────────────────────────────────
void initRTC(){
  if(!rtc.begin()){
    Serial.println("RTC init failed"); while(1);
  }
  if(!rtc.isrunning()){
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

// ─── COMPUTE ABSOLUTE STEP POSITION ─────────────────────────────────────
uint16_t computeStepCount(uint8_t idx, uint8_t state){
  if(idx < 4){
    // Digit spools
    return state * STEPS_PER_DIGIT;
  }
  else if(idx < 6){
    // A/P and Mchar spools
    return state * STEPS_AP_M;
  }
  // Weekday spool
  return state * STEPS_PER_DAY;
}

// ─── FORWARD-ONLY STEPPING (WITH WRAP) ───────────────────────────────────
void stepForward(uint8_t idx, uint16_t targetStep){
  uint16_t oldStep = computeStepCount(idx, currentState[idx]);
  uint16_t rev     = (idx<6 ? STEPS_REV_DIG : STEPS_REV_WD);
  uint16_t delta   = (targetStep >= oldStep)
                    ? (targetStep - oldStep)
                    : (rev - (oldStep - targetStep));

  // Pulse STEP pin delta times
  for(uint16_t s=0; s<delta; s++){
    digitalWrite(STEP_PINS[idx], HIGH);
    delayMicroseconds(600);
    digitalWrite(STEP_PINS[idx], LOW);
    delayMicroseconds(600);
  }
}