#include <TM1637Display.h>

/* ===== 핀/설정 ===== */

#define TM_CLK   2

#define TM_DIO   3

#define BTN_MODE 4

#define BTN_START 5

#define BTN_UP   6

#define BTN_DOWN 7

#define BUZZER_PIN 9

const uint8_t  DISPLAY_BRIGHTNESS = 7;      // 0~7

const bool     USE_PASSIVE_BUZZER = false;  // Passive면 true

const uint16_t DEBOUNCE_MS = 35;

const uint16_t LONG_PRESS_MS = 1200;

const uint16_t RESET_PRESS_MS = 2000;

const uint16_t DEFAULT_TIMER_MIN = 1;

const uint16_t MAX_MINUTES = 99;

/* ===== 전역 ===== */

TM1637Display display(TM_CLK, TM_DIO);

bool running = false;

bool colon_state = true;

uint32_t lastTick = 0;

uint32_t lastBlink = 0;

bool blinkOn = true;

int32_t timer_seconds = DEFAULT_TIMER_MIN * 60;

// 설정 모드 상태

bool inSetting = false;

uint8_t setIdx = 0;

int32_t editing_seconds = 0;

/* ===== 버튼 구조/생성자 ===== */

struct Btn {

  uint8_t  pin;

  bool     last;

  uint32_t tChange;

  bool     longFired;

  Btn(uint8_t p) : pin(p), last(true), tChange(0), longFired(false) {}

  Btn() : pin(0), last(true), tChange(0), longFired(false) {}

};

Btn bMode(BTN_MODE), bStart(BTN_START), bUp(BTN_UP), bDown(BTN_DOWN);

/* ===== 표시 ===== */

void showMMSS_raw(uint16_t mm, uint16_t ss, bool colonOn, int8_t blinkPos = -1, bool blinkState = true){

  uint8_t segs[4];

  segs[0] = display.encodeDigit((mm/10)%10);

  segs[1] = display.encodeDigit(mm%10);

  segs[2] = display.encodeDigit((ss/10)%10);

  segs[3] = display.encodeDigit(ss%10);

  if(colonOn) segs[1] |= 0x80;         // 가운데 콜론

  if(blinkPos>=0 && !blinkState) segs[blinkPos] = 0x00;

  display.setBrightness(DISPLAY_BRIGHTNESS, true);

  display.setSegments(segs);

}

void showSeconds(int32_t s, bool colonOn){

  if(s<0) s=0;

  if(s>(int32_t)(MAX_MINUTES*60+59)) s=MAX_MINUTES*60+59;

  uint16_t mm = s/60, ss=s%60;

  showMMSS_raw(mm, ss, colonOn);

}

/* ===== 논블로킹 부저 ===== */

enum BeepMode { BEEP_OFF, BEEP_END };

BeepMode beepMode = BEEP_OFF;

uint32_t beepUntil = 0;

uint32_t nextToggle = 0;

bool buzOn = false;

void buzzerOn(){

  if (USE_PASSIVE_BUZZER) tone(BUZZER_PIN, 2000);

  else digitalWrite(BUZZER_PIN, HIGH);

  buzOn = true;

}

void buzzerOff(){

  if (USE_PASSIVE_BUZZER) noTone(BUZZER_PIN);

  else digitalWrite(BUZZER_PIN, LOW);

  buzOn = false;

}

// 종료 패턴(3초: 120ms ON / 80ms OFF 반복)

const uint16_t END_ON_MS  = 120;

const uint16_t END_OFF_MS = 80;

void startEndBeep(uint16_t total_ms = 3000){

  beepMode  = BEEP_END;

  uint32_t now = millis();

  beepUntil = now + total_ms;

  buzzerOn();

  nextToggle = now + END_ON_MS;

}

void updateBeep(){

  uint32_t now = millis();

  if(beepMode == BEEP_END){

    if(now >= beepUntil){

      buzzerOff();

      beepMode = BEEP_OFF;

    }else if(now >= nextToggle){

      if(buzOn){

        buzzerOff();

        nextToggle = now + END_OFF_MS;

      }else{

        buzzerOn();

        nextToggle = now + END_ON_MS;

      }

    }

  }

}

/* ===== 설정모드 유틸 ===== */

int clamp01(int v){ if(v<0) return 0; if(v>9) return 9; return v; }

void applyDigitChange(int8_t idx, int8_t delta, int32_t &sec){

  int mm = sec/60, ss = sec%60;

  int d0 = (mm/10)%10, d1 = mm%10, d2 = (ss/10)%10, d3 = ss%10;

  if(idx==0) d0 = clamp01(d0 + delta);

  else if(idx==1) d1 = clamp01(d1 + delta);

  else if(idx==2){ d2 = clamp01(d2 + delta); if(d2>5) d2=5; }

  else if(idx==3) d3 = clamp01(d3 + delta);

  mm = d0*10 + d1; if(mm>MAX_MINUTES) mm = MAX_MINUTES;

  ss = d2*10 + d3; if(ss>59) ss=59;

  sec = mm*60 + ss;

}

/* ===== 버튼 스캐너 ===== */

void scanBtn(Btn &b, void (*onShort)(), void (*onLong)(), uint32_t longMs){

  bool now = digitalRead(b.pin);

  uint32_t t = millis();

  if (now != b.last && (t - b.tChange) > DEBOUNCE_MS) {

    b.tChange = t;

    bool was = b.last;

    b.last = now;

    if (now == LOW) {

      b.longFired = false;

    } else {

      if (!b.longFired && onShort) onShort();

    }

  }

  if (b.last == LOW && !b.longFired && (millis() - b.tChange) > longMs) {

    b.longFired = true;

    if (onLong) onLong();

  }

}

/* ===== 버튼 콜백 ===== */

void onModeShort(){

  if(running) return;

  if(inSetting){

    setIdx++;

    if(setIdx>3){ timer_seconds = editing_seconds; inSetting=false; }

  }

}

void onModeLong(){

  if(running) return;

  inSetting = !inSetting;

  editing_seconds = timer_seconds;

  setIdx = 0;

}

void onStartShort(){

  if(inSetting){ 

    timer_seconds = editing_seconds; 

    inSetting=false; 

    return; 

  }

  running = !running;

  if (running) {

    // 시작 시점 기준으로 lastTick 리셋

    lastTick = millis();

  }

}

void onStartLong(){

  running = false;

  timer_seconds = DEFAULT_TIMER_MIN * 60;

  if(inSetting) editing_seconds = timer_seconds;

}

void onUpShort(){

  if(inSetting) applyDigitChange(setIdx, +1, editing_seconds);

  else if(!running){ int mm = timer_seconds/60; if(mm<MAX_MINUTES) mm++; timer_seconds = mm*60; }

}

void onUpLong(){

  if(inSetting){ for(int i=0;i<5;i++) applyDigitChange(setIdx, +1, editing_seconds); }

  else if(!running){ int mm = timer_seconds/60; mm = (mm+10>MAX_MINUTES)?MAX_MINUTES:mm+10; timer_seconds = mm*60; }

}

void onDownShort(){

  if(inSetting) applyDigitChange(setIdx, -1, editing_seconds);

  else if(!running){ int mm = timer_seconds/60; if(mm>0) mm--; timer_seconds = mm*60; }

}

void onDownLong(){

  if(inSetting){ for(int i=0;i<5;i++) applyDigitChange(setIdx, -1, editing_seconds); }

  else if(!running){ int mm = timer_seconds/60; mm = (mm-10<0)?0:mm-10; timer_seconds = mm*60; }

}

/* ===== setup/loop ===== */

void setup(){

  pinMode(BTN_MODE, INPUT_PULLUP);

  pinMode(BTN_START, INPUT_PULLUP);

  pinMode(BTN_UP, INPUT_PULLUP);

  pinMode(BTN_DOWN, INPUT_PULLUP);

  pinMode(BUZZER_PIN, OUTPUT);

  digitalWrite(BUZZER_PIN, LOW);

  display.setBrightness(DISPLAY_BRIGHTNESS, true);

  display.clear();

  lastTick = millis();

  lastBlink = millis();

}

void loop(){

  // 버튼 스캔

  scanBtn(bMode,  onModeShort,  onModeLong,  LONG_PRESS_MS);

  scanBtn(bStart, onStartShort, onStartLong, RESET_PRESS_MS);

  scanBtn(bUp,    onUpShort,    onUpLong,    LONG_PRESS_MS);

  scanBtn(bDown,  onDownShort,  onDownLong,  LONG_PRESS_MS);

  uint32_t now = millis();

  // 1초마다 카운트

  if(now - lastTick >= 1000){

    lastTick += 1000;

    if(running && !inSetting){

      if(timer_seconds > 0){

        timer_seconds--;

        if (timer_seconds == 0){

          running = false;

          startEndBeep(3000);

        }

      }

    }

    colon_state = !colon_state;

  }

  // 설정자리 깜빡임

  if(now - lastBlink >= 300){

    lastBlink += 300;

    blinkOn = !blinkOn;

  }

  // 표시

  if(inSetting){

    int32_t s = editing_seconds;

    if(s<0) s=0;

    if(s>(int32_t)(MAX_MINUTES*60+59)) s=MAX_MINUTES*60+59;

    uint16_t mm = s/60, ss = s%60;

    showMMSS_raw(mm, ss, true, setIdx, blinkOn);

  }else{

    showSeconds(timer_seconds, running ? colon_state : true);

  }

  // 부저 상태 갱신

  updateBeep();

}