import React, { useState, useMemo } from 'react';
import './IDCardInput.css';

const WEIGHTS = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2];
const CHECK = '10X98765432';
function validate(v) {
  if (!/^\d{17}[\dX]$/.test(v)) return null;
  let sum = 0;
  for (let i = 0; i < 17; i++) sum += parseInt(v[i], 10) * WEIGHTS[i];
  if (CHECK[sum % 11] !== v[17]) return null;
  const birth = v.slice(6, 14);
  return { birth: birth.slice(0, 4) + '-' + birth.slice(4, 6) + '-' + birth.slice(6, 8), gender: parseInt(v[16], 10) % 2 === 1 ? '男' : '女' };
}

export default function IDCardInput({ modelValue = '', placeholder = '请输入 18 位身份证号', onChange }) {
  const [focused, setFocused] = useState(false);
  const result = useMemo(() => validate(modelValue.toUpperCase()) || {}, [modelValue]);
  const valid = !!result.birth;
  const invalid = modelValue.length === 18 && !result.birth;
  const tipClass = !modelValue ? '' : valid ? 'valid' : invalid ? 'invalid' : '';
  const tipText = !modelValue
    ? '示例：11010119900307657X'
    : modelValue.length < 18
    ? '已输入 ' + modelValue.length + ' 位，继续…'
    : valid
    ? '校验通过'
    : '身份证号校验失败，请检查';

  const onInput = (e) => {
    const v = e.target.value.replace(/[^0-9Xx]/g, '').toUpperCase().slice(0, 18);
    e.target.value = v;
    if (onChange) onChange(v);
  };

  return (
    <div className="kole-idcard">
      <div
        className={'kole-idcard-field' + (focused ? ' is-focus' : '') + (valid ? ' is-valid' : '') + (invalid ? ' is-invalid' : '')}
      >
        <input
          className="kole-idcard-input"
          value={modelValue}
          maxLength={18}
          placeholder={placeholder}
          onInput={onInput}
          onFocus={() => setFocused(true)}
          onBlur={() => setFocused(false)}
        />
      </div>
      {result.birth && (
        <div className="kole-idcard-info">
          <span>出生日期：<b>{result.birth}</b></span>
          <span>性别：<b>{result.gender}</b></span>
        </div>
      )}
      <div className={'kole-idcard-tip ' + tipClass}>{tipText}</div>
    </div>
  );
}