/**
 * Utility Functions
 * 유틸리티 함수 모음
 */

/**
 * 가격 포맷팅 (한국 원화)
 */
export function formatPrice(price) {
  return '₩' + price.toLocaleString('ko-KR');
}

/**
 * 탭 전환 (n8n/Terraform)
 */
export function switchTab(tab) {
  const btnN8n = document.getElementById('btn-n8n');
  const btnTf = document.getElementById('btn-tf');
  const panelN8n = document.getElementById('panel-n8n');
  const panelTf = document.getElementById('panel-tf');

  // Null checks for DOM elements
  if (!btnN8n || !btnTf || !panelN8n || !panelTf) return;

  if (tab === 'n8n') {
    // Update ARIA states for n8n tab
    btnN8n.setAttribute('aria-selected', 'true');
    btnN8n.setAttribute('tabindex', '0');
    btnTf.setAttribute('aria-selected', 'false');
    btnTf.setAttribute('tabindex', '-1');

    // Update classes
    btnN8n.className = 'px-4 py-2 rounded-lg bg-purple-600 text-white text-sm font-bold transition shadow-lg shadow-purple-500/20';
    btnTf.className = 'px-4 py-2 rounded-lg bg-slate-800 text-slate-400 text-sm font-bold border border-slate-700 hover:text-white transition';
    panelN8n.classList.remove('hidden');
    panelTf.classList.add('hidden');
  } else {
    // Update ARIA states for Terraform tab
    btnTf.setAttribute('aria-selected', 'true');
    btnTf.setAttribute('tabindex', '0');
    btnN8n.setAttribute('aria-selected', 'false');
    btnN8n.setAttribute('tabindex', '-1');

    // Update classes
    btnN8n.className = 'px-4 py-2 rounded-lg bg-slate-800 text-slate-400 text-sm font-bold border border-slate-700 hover:text-white transition';
    btnTf.className = 'px-4 py-2 rounded-lg bg-blue-600 text-white text-sm font-bold transition shadow-lg shadow-blue-500/20';
    panelN8n.classList.add('hidden');
    panelTf.classList.remove('hidden');
  }
}

/**
 * 실시간 Ping 시뮬레이션
 */
export function updatePing() {
  const regions = [
    { id: 'ping-kr', base: 2, variance: 2 },
    { id: 'ping-jp', base: 35, variance: 5 },
    { id: 'ping-hk', base: 45, variance: 8 },
    { id: 'ping-sg', base: 65, variance: 10 }
  ];

  regions.forEach(region => {
    const el = document.getElementById(region.id);
    if (el) {
      const jitter = Math.floor(Math.random() * region.variance) - (region.variance / 2);
      let val = Math.max(1, Math.floor(region.base + jitter));
      el.innerText = val;
    }
  });
}

// Ping 업데이트 시작 (visibility-aware)
let pingInterval;

export function startPingUpdates() {
  if (!pingInterval) {
    pingInterval = setInterval(updatePing, 2000);
  }
}

export function stopPingUpdates() {
  if (pingInterval) {
    clearInterval(pingInterval);
    pingInterval = null;
  }
}

// Visibility change handler
document.addEventListener('visibilitychange', () => {
  if (document.hidden) {
    stopPingUpdates();
  } else {
    startPingUpdates();
  }
});

// Initial start
startPingUpdates();

// Tab switching with event listeners and keyboard navigation
document.addEventListener('DOMContentLoaded', () => {
  const btnN8n = document.getElementById('btn-n8n');
  const btnTf = document.getElementById('btn-tf');

  if (btnN8n && btnTf) {
    // Click event listeners
    btnN8n.addEventListener('click', () => switchTab('n8n'));
    btnTf.addEventListener('click', () => switchTab('tf'));

    // Keyboard navigation (Arrow keys)
    [btnN8n, btnTf].forEach(btn => {
      btn.addEventListener('keydown', (e) => {
        const currentTab = btn.getAttribute('data-tab');

        if (e.key === 'ArrowRight') {
          e.preventDefault();
          if (currentTab === 'n8n') {
            btnTf.focus();
            switchTab('tf');
          }
        } else if (e.key === 'ArrowLeft') {
          e.preventDefault();
          if (currentTab === 'tf') {
            btnN8n.focus();
            switchTab('n8n');
          }
        }
      });
    });
  }
});