function zipWith<T, R>(a1: T[], a2: T[], f: (v1: T, v2: T) => R): R[] {
  const length = Math.min(a1.length, a2.length)
  const result: R[] = []

  for (let i = 0; i < length; i++) result[i] = f(a1[i], a2[i])

  return result
}

function add(a: number, b: number) {
  return a + b
}

function multiply(a: number, b: number) {
  return a * b
}

/**
 * Verify the input is a valid GUI Number (中華民國統一編號)
 *
 * @param { string | number } input GUI Number
 * @param { boolean } extended check input using extended format: https://www.fia.gov.tw/singlehtml/6?cntId=aaa97a9dcf2649d5bdd317f554e24f75
 * @returns { boolean } is `input` a valid GUI number
 */
export function isGuiNumberValid(
  input: string | number,
  extended = false
): boolean {
  if (typeof input !== 'string' && typeof input !== 'number') return false

  /**
   * Example: 12345675
   * Step 1:
   * 1 * 1 = 1
   * 2 * 2 = 4
   * 3 * 1 = 3
   * 4 * 2 = 8
   * 5 * 1 = 5
   * 6 * 2 = 12
   * 7 * 4 = 28
   * 5 * 1 = 5
   *
   * Step 2:
   * 1 -> 1
   * 4 -> 4
   * 3 -> 3
   * 8 -> 8
   * 5 -> 5
   * 12 -> 1 + 2 = 3
   * 28 -> 2 + 8 = 10
   * 5 -> 5
   *
   * Step 3:
   * (1 + 4 + 3 + 8 + 5 + 3 + 10 + 5) % 10 = 9
   */

  const GUI_NUMBER_COEFFICIENTS = [1, 2, 1, 2, 1, 2, 4, 1]

  const n = input.toString()
  const regex = /^\d{8}$/

  if (!regex.test(n)) return false

  /**
   * Step 1: 先把統一編號的每個數字分別乘上對應的係數 (1, 2, 1, 2, 1, 2, 4, 1)
   * Step 2: 再把個別乘積的十位數與個位數相加，得出八個小於 10 的數字
   */

  const intRadix = 10
  const checksum = zipWith(
    GUI_NUMBER_COEFFICIENTS,
    n.split('').map(c => parseInt(c, intRadix)),
    multiply
  )
    .map(n => (n % 10) + Math.floor(n / 10))
    .reduce(add, 0)

  /**
   * Step 3: 檢查把這 8 個數字相加之後計算此和除以 5 or 10 的餘數
   * Step 4:
   *  4-1: 若是餘數為 0，則為正確的統一編號
   *  4-2: 若是餘數為 9，且原統一編號的第七位是 7，則也為正確的統一編號
   */

  const divisor = extended ? 5 : 10

  return (
    checksum % divisor === 0 ||
    (parseInt(n.charAt(6), intRadix) === 7 && (checksum + 1) % divisor === 0)
  )
}

/**
 * Verify the input is a valid National identification number (中華民國身分證字號)
 *
 * @param { string } input National identification number
 * @returns { boolean } is `input` a valid national ID number
 */
export function isNationalIdentificationNumberValid(input: string): boolean {
  if (typeof input !== 'string') return false

  const regex = /^[A-Z][1,2]\d{8}$/

  return regex.test(input) && verifyTaiwanIdIntermediateString(input)
}

/**
 * Verify the input is a valid resident certificate number (臺灣地區無戶籍國民、外國人、大陸地區人民及香港或澳門居民之專屬代號)
 *
 * @param { string } input resident certificate number
 * @returns { boolean } is `input` a valid resident certificate number
 */
export function isResidentCertificateNumberValid(input: string): boolean {
  if (typeof input !== 'string') return false

  return (
    isNewResidentCertificateNumberValid(input) ||
    isOriginalResidentCertificateNumberValid(input)
  )
}

/**
 * Verify the input is a valid new resident certificate number (臺灣地區無戶籍國民、外國人、大陸地區人民及香港或澳門居民之專屬代號)
 *
 * @param { string } input resident certificate number
 * @returns { boolean } is `input` a valid new resident certificate number
 */
export function isNewResidentCertificateNumberValid(input: string): boolean {
  if (typeof input !== 'string') return false

  const regex = /^[A-Z][8,9]\d{8}$/

  return regex.test(input) && verifyTaiwanIdIntermediateString(input)
}

/**
 * Verify the input is a original valid resident certificate number (臺灣地區無戶籍國民、外國人、大陸地區人民及香港或澳門居民之專屬代號)
 *
 * @param { string } input resident certificate number
 * @returns { boolean } is `input` a valid original resident certificate number
 */
export function isOriginalResidentCertificateNumberValid(
  input: string
): boolean {
  if (typeof input !== 'string') return false

  const regex = /^[A-Z]{2}\d{8}$/

  return regex.test(input) && verifyTaiwanIdIntermediateString(input)
}

/**
 * Verify the input is a valid citizen digital certificate number (自然人憑證)
 *
 * @param { string } input citizen digital certificate number
 * @returns { boolean } is `input` a valid citizen digital certificate number
 */
export function isCitizenDigitalCertificateNumberValid(input: string): boolean {
  if (typeof input !== 'string') return false

  const n = input.toString()

  // 驗證規則為兩碼英文 + 14 碼數字
  const regex = /^[A-Z]{2}\d{14}$/

  return regex.test(n)
}

/**
 * Verify the input is a valid E-Invoice cell phone barcode (電子發票手機條碼)
 *
 * @param { string } input E-Invoice cell phone barcode
 * @returns { boolean } is `input` a valid e-invoice cell phone barcode
 */
export function isEInvoiceCellPhoneBarcodeValid(input: string): boolean {
  if (typeof input !== 'string') return false

  const n = input.toString()

  /**
   * 總長度為 8 碼
   * 第 1 碼為 /
   * 第 2-8 碼由 0-9 (數字), A-Z (大寫英文字母), .(period), -(hyphen), +(plus) 組成
   */
  const regex = /^\/[\dA-Z.\-+]{7}$/

  return regex.test(n)
}

/**
 * Verify the input is a valid E-Invoice donate code (電子發票捐贈碼)
 *
 * @param { string | number } input E-Invoice donate code
 * @returns { boolean } is `input` a valid e-invoice donate code
 */
export function isEInvoiceDonateCodeValid(input: string | number): boolean {
  if (typeof input !== 'string' && typeof input !== 'number') return false

  const n = input.toString()

  // 總長度為 3-7 碼 0-9 的數字
  const regex = /^[\d]{3,7}$/

  return regex.test(n)
}

export type CreditCardValidationOptions = {
  /**
   * validate `input` with regex
   * (Warning! Card issuers might introduce new card number patterns. Use this in production might cause unexpected results.)
   */
  checkIssuerRegexes?: boolean
}

/**
 * Verify the input is a valid credit card number (信用卡卡號)
 *
 * @param { string | number } input credit card number
 * @param { CreditCardValidationOptions } creditCardValidationOptions credit card validation options
 * @returns { boolean } is `input` a valid credit card number
 */
export function isCreditCardNumberValid(input: string, options: CreditCardValidationOptions = {}): boolean {
  if (typeof input !== 'string') return false

  const regex = /^[0-9]{12,19}$/

  if (!regex.test(input)) return false

  // ref:
  //   https://stackoverflow.com/questions/9315647/regex-credit-card-number-tests
  //   https://en.wikipedia.org/wiki/Payment_card_number
  const issuerRegexes = [
    /^3[47][0-9]{13}$/, // American Express
    /^(6541|6556)[0-9]{12}$/, // BCGlobal
    /^389[0-9]{11}$/, // Carte Blanche
    /^3(?:0[0-5]|[68][0-9])[0-9]{11}$/, // Diner's Club
    /^65[4-9][0-9]{13}|64[4-9][0-9]{13}|6011[0-9]{12}|(622(?:12[6-9]|1[3-9][0-9]|[2-8][0-9][0-9]|9[01][0-9]|92[0-5])[0-9]{10})$/, // Discover
    /^63[7-9][0-9]{13}$/, // Insta Payment
    /^(?:2131|1800|35\d{3})\d{11}$/, // JCB
    /^9[0-9]{15}$/, // KoreanLocalCard
    /^(6304|6706|6709|6771)[0-9]{12,15}$/, // Laser
    /^(5018|5020|5038|6304|6759|6761|6763)[0-9]{8,15}$/, // Maestro
    /^(5[1-5][0-9]{14}|2(22[1-9][0-9]{12}|2[3-9][0-9]{13}|[3-6][0-9]{14}|7[0-1][0-9]{13}|720[0-9]{12}))$/, // Mastercard
    /^(6334|6767)[0-9]{12}|(6334|6767)[0-9]{14}|(6334|6767)[0-9]{15}$/, // Solo
    /^(4903|4905|4911|4936|6333|6759)[0-9]{12}|(4903|4905|4911|4936|6333|6759)[0-9]{14}|(4903|4905|4911|4936|6333|6759)[0-9]{15}|564182[0-9]{10}|564182[0-9]{12}|564182[0-9]{13}|633110[0-9]{10}|633110[0-9]{12}|633110[0-9]{13}$/, // Switch
    /^(62[0-9]{14,17})$/, // Union Pay
    /^4[0-9]{12}(?:[0-9]{3})?$/, // Visa
    /^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14})$/ // Visa Master
  ]

  const { checkIssuerRegexes = false } = options

  if (checkIssuerRegexes && !issuerRegexes.some(regex => regex.test(input)))
    return false

  // Luhn algorithm
  // ref: https://en.wikipedia.org/wiki/Luhn_algorithm
  const digits = input.split('').map(d => parseInt(d, 10))
  const sum = digits.reverse().reduce((acc, d, i) => {
    if (i % 2 === 0) return acc + d
    return acc + (d * 2 > 9 ? d * 2 - 9 : d * 2)
  }, 0)

  return sum % 10 === 0
}

/**
 * Verify the intermediate string for isNationalIdentificationNumberValid and isResidentCertificateNumberValid
 *
 * @param { string } input String to verify
 * @returns { boolean } is `input` a valid Taiwan ID intermediate string
 */
function verifyTaiwanIdIntermediateString(input: string): boolean {
  const intRadix = 10

  /**
   *  A=10 台北市     J=18 新竹縣     S=26 高雄縣
   *  B=11 台中市     K=19 苗栗縣     T=27 屏東縣
   *  C=12 基隆市     L=20 台中縣     U=28 花蓮縣
   *  D=13 台南市     M=21 南投縣     V=29 台東縣
   *  E=14 高雄市     N=22 彰化縣     W=32 金門縣*
   *  F=15 台北縣     O=35 新竹市*    X=30 澎湖縣
   *  G=16 宜蘭縣     P=23 雲林縣     Y=31 陽明山
   *  H=17 桃園縣     Q=24 嘉義縣     Z=33 連江縣*
   *  I=34 嘉義市*    R=25 台南縣
   *
   *  Step 1: 英文字母按照上表轉換為數字之後，十位數 * 1 + 個位數 * 9 相加
   */
  const TAIWAN_ID_LOCALE_CODE_LIST = [
    1, // A -> 10 -> 1 * 1 + 9 * 0 = 1
    10, // B -> 11 -> 1 * 1 + 9 * 1 = 10
    19, // C -> 12 -> 1 * 1 + 9 * 2 = 19
    28, // D
    37, // E
    46, // F
    55, // G
    64, // H
    39, // I -> 34 -> 1 * 3 + 9 * 4 = 39
    73, // J
    82, // K
    2, // L
    11, // M
    20, // N
    48, // O -> 35 -> 1 * 3 + 9 * 5 = 48
    29, // P
    38, // Q
    47, // R
    56, // S
    65, // T
    74, // U
    83, // V
    21, // W -> 32 -> 1 * 3 + 9 * 2 = 21
    3, // X
    12, // Y
    30 // Z -> 33 -> 1 * 3 + 9 * 3 = 30
  ]

  const RESIDENT_CERTIFICATE_NUMBER_LIST = [
    0, // A
    1, // B
    2, // C
    3, // D
    4, // E
    5, // F
    6, // G
    7, // H
    4, // I
    8, // J
    9, // K
    0, // L
    1, // M
    2, // N
    5, // O
    3, // P
    4, // Q
    5, // R
    6, // S
    7, // T
    8, // U
    9, // V
    2, // W
    0, // X
    1, // Y
    3 // Z
  ]

  const getCharOrder = (s: string, i: number) =>
    s.charCodeAt(i) - 'A'.charCodeAt(0)

  const firstDigit = TAIWAN_ID_LOCALE_CODE_LIST[getCharOrder(input, 0)]

  const secondDigit = isNaN(parseInt(input[1], intRadix)) // if is not a number (舊版居留證編號)
    ? RESIDENT_CERTIFICATE_NUMBER_LIST[getCharOrder(input, 1)]
    : parseInt(input[1], intRadix)

  const rest = input
    .substring(2)
    .split('')
    .map(n => parseInt(n, intRadix))

  const idInDigits = [firstDigit, secondDigit, ...rest]

  // Step 2: 第 1 位數字 (只能為 1 or 2) 至第 8 位數字分別乘上 8, 7, 6, 5, 4, 3, 2, 1 後相加，再加上第 9 位數字

  const ID_COEFFICIENTS = [1, 8, 7, 6, 5, 4, 3, 2, 1, 1]
  const sum = zipWith(idInDigits, ID_COEFFICIENTS, multiply).reduce(add, 0)

  // Step 3: 如果該數字為 10 的倍數，則為正確身分證字號

  return sum % 10 === 0
}

export const isGUI = isGuiNumberValid
export const isNI = isNationalIdentificationNumberValid
export const isRC = isResidentCertificateNumberValid
export const isNewRC = isNewResidentCertificateNumberValid
export const isOriginalRC = isOriginalResidentCertificateNumberValid
export const isCDC = isCitizenDigitalCertificateNumberValid
export const isCellPhoneBarcode = isEInvoiceCellPhoneBarcodeValid
export const isDonateCode = isEInvoiceDonateCodeValid
export const isCreditCard = isCreditCardNumberValid