document.addEventListener('DOMContentLoaded', () => {

  const smsBtn   = document.getElementById('sms_button');
  const phoneInp = document.getElementById('login_phone');

  if (!smsBtn || !phoneInp) return;

  const form    = smsBtn.closest('form');
  const infoBox = form.querySelector('.info-box');
  const timerEl = form.querySelector('.timer');

  let pollTimer  = null;
  let timerIntv  = null;
  let remain     = 180; // 3분

  function startTimer() {
    clearInterval(timerIntv);
    remain = 180;

    timerEl.classList.remove('d-none');
    updateTimer();

    timerIntv = setInterval(() => {
      remain--;
      updateTimer();

      if (remain <= 0) {
        clearInterval(timerIntv);
        smsBtn.disabled = false;
        timerEl.textContent = '00:00';
      }
    }, 1000);
  }

  function updateTimer() {
    const m = String(Math.floor(remain / 60)).padStart(2, '0');
    const s = String(remain % 60).padStart(2, '0');
    timerEl.textContent = `${m}:${s}`;
  }

  smsBtn.addEventListener('click', async (e) => {
    e.preventDefault();

    const phone = phoneInp.value.trim();
    if (!phone) {
      alert('휴대폰 번호를 입력하세요.');
      phoneInp.focus();
      return;
    }

    smsBtn.disabled = true;

    try {
      const res = await fetch('/kngil/bbs/login_sms.php', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          mode: 'request',
          phone
        })
      });

      const json = await res.json();

      if (json.status !== 'success') {
        alert(json.message || '인증 링크 요청 실패');
        smsBtn.disabled = false;
        return;
      }

      // UI 처리
      infoBox.classList.remove('d-none');
      startTimer();
      startPolling();

    } catch (err) {
      console.error(err);
      alert('인증 요청 중 오류');
      smsBtn.disabled = false;
    }
  });

  function startPolling() {
    clearInterval(pollTimer);

    pollTimer = setInterval(async () => {
      try {
        const res = await fetch('/kngil/bbs/login_sms.php?mode=status');
        const json = await res.json();

        if (json.status === 'success') {
          clearInterval(pollTimer);
          clearInterval(timerIntv);
          location.reload();
        }
      } catch (e) {
        console.error(e);
      }
    }, 3000);
  }

});