/**
 * 入职登记表固定字段校验工具。
 *
 * 前端校验用于即时提示，后端仍会执行同样的核心校验，避免绕过页面直接提交非法数据。
 */

const mobilePhonePattern = /^1[3-9]\d{9}$/;
const landlinePhonePattern = /^0\d{2,3}-?\d{7,8}$/;
const emailPattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
const bankCardPattern = /^\d{12,19}$/;

const idCardWeights = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2];
const idCardCheckCodes = ["1", "0", "X", "9", "8", "7", "6", "5", "4", "3", "2"];

export function normalizeIdCardNumber(value: unknown) {
  return String(value ?? "").trim().toUpperCase();
}

export function normalizeBankCardNumber(value: unknown) {
  return String(value ?? "").replace(/[\s-]/g, "");
}

export function isMobilePhone(value: unknown) {
  return mobilePhonePattern.test(String(value ?? "").trim());
}

export function isContactPhone(value: unknown) {
  const phone = String(value ?? "").trim();
  return mobilePhonePattern.test(phone) || landlinePhonePattern.test(phone);
}

export function isEmail(value: unknown) {
  return emailPattern.test(String(value ?? "").trim());
}

export function isBankCardNumber(value: unknown) {
  return bankCardPattern.test(normalizeBankCardNumber(value));
}

/**
 * 校验中国大陆 18 位居民身份证，包括出生日期和校验位。
 * 返回空字符串表示校验通过，否则返回适合直接展示给用户的错误信息。
 */
export function getIdCardValidationMessage(value: unknown) {
  const idCardNumber = normalizeIdCardNumber(value);
  if (!/^\d{17}[0-9X]$/.test(idCardNumber)) {
    return "请输入正确的18位身份证号码";
  }

  const birthday = getIdCardBirthday(idCardNumber);
  if (!birthday || !isValidDateText(birthday) || birthday > getTodayText()) {
    return "身份证号码中的出生日期不正确";
  }

  const total = idCardWeights.reduce(
    (sum, weight, index) => sum + Number(idCardNumber[index]) * weight,
    0
  );
  if (idCardCheckCodes[total % 11] !== idCardNumber[17]) {
    return "身份证号码校验位不正确";
  }

  return "";
}

export function getIdCardBirthday(value: unknown) {
  const idCardNumber = normalizeIdCardNumber(value);
  if (!/^\d{17}[0-9X]$/.test(idCardNumber)) {
    return "";
  }

  const text = idCardNumber.slice(6, 14);
  return `${text.slice(0, 4)}-${text.slice(4, 6)}-${text.slice(6, 8)}`;
}

export function getIdCardGender(value: unknown) {
  const idCardNumber = normalizeIdCardNumber(value);
  if (!/^\d{17}[0-9X]$/.test(idCardNumber)) {
    return "";
  }

  const genderCode = Number(idCardNumber.charAt(16));
  return genderCode % 2 === 1 ? "男" : "女";
}

export function isNumberInRange(value: unknown, min: number, max: number) {
  const text = String(value ?? "").trim();
  if (!/^\d+(\.\d+)?$/.test(text)) {
    return false;
  }

  const number = Number(text);
  return Number.isFinite(number) && number >= min && number <= max;
}

function isValidDateText(value: string) {
  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
  if (!match) {
    return false;
  }

  const year = Number(match[1]);
  const month = Number(match[2]);
  const day = Number(match[3]);
  const date = new Date(year, month - 1, day);
  return date.getFullYear() === year
    && date.getMonth() === month - 1
    && date.getDate() === day;
}

function getTodayText() {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, "0");
  const day = String(now.getDate()).padStart(2, "0");
  return `${year}-${month}-${day}`;
}