<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Kole UI · BankCardInput</title>
  <link rel="stylesheet" href="../.design_library/kole-ui/colors_and_type.css" />
  <link rel="stylesheet" href="./BankCardInput.css" />
</head>
<body>
  <div class="kole-page">
    <h2 class="kole-h2">BankCardInput 银行卡输入</h2>
    <p class="kole-desc">自动每 4 位空格、识别卡组织、Luhn 校验。</p>

    <div class="kole-demo">
      <div class="kole-demo__title">基础用法</div>
      <div class="kole-card" id="card">
        <div class="kole-card-field" id="field">
          <input class="kole-card-input" id="input" placeholder="请输入银行卡号" inputmode="numeric" maxlength="23" />
          <span class="kole-card-type unknown" id="type">识别中</span>
        </div>
        <div class="kole-card-tip" id="tip">支持 Visa / MasterCard / 银联等</div>
      </div>
    </div>
  </div>

  <script>
    function detectType(v) {
      if (/^4/.test(v)) return 'Visa';
      if (/^5[1-5]/.test(v)) return 'MasterCard';
      if (/^62/.test(v)) return '银联';
      if (/^3[47]/.test(v)) return 'AmEx';
      if (/^35/.test(v)) return 'JCB';
      return '';
    }
    function luhn(v) {
      var sum = 0, alt = false;
      for (var i = v.length - 1; i >= 0; i--) {
        var n = parseInt(v[i], 10);
        if (alt) { n *= 2; if (n > 9) n -= 9; }
        sum += n; alt = !alt;
      }
      return sum % 10 === 0;
    }

    var field = document.getElementById('field');
    var input = document.getElementById('input');
    var typeEl = document.getElementById('type');
    var tip = document.getElementById('tip');

    input.addEventListener('input', function () {
      var digits = input.value.replace(/\D/g, '').slice(0, 19);
      var grouped = digits.replace(/(.{4})/g, '$1 ').trim();
      input.value = grouped;
      var t = detectType(digits);
      typeEl.textContent = t || '未知';
      typeEl.className = 'kole-card-type' + (t ? '' : ' unknown');
      var len = digits.length;
      field.classList.remove('is-valid', 'is-invalid');
      tip.className = 'kole-card-tip';
      if (!len) { tip.textContent = '支持 Visa / MasterCard / 银联等'; }
      else if (len >= 13 && luhn(digits)) { field.classList.add('is-valid'); tip.className = 'kole-card-tip valid'; tip.textContent = '卡号校验通过'; }
      else if (len >= 13) { field.classList.add('is-invalid'); tip.className = 'kole-card-tip invalid'; tip.textContent = '卡号未通过 Luhn 校验'; }
      else { tip.textContent = '继续输入卡号…'; }
    });
    input.addEventListener('focus', function () { field.classList.add('is-focus'); });
    input.addEventListener('blur', function () { field.classList.remove('is-focus'); });
  </script>
</body>
</html>
