TcValidator.kt

fun String.isValidTcNo(): Boolean {
    val tcNo = this.trim()
    if (tcNo.length != 11)
        return false
    if (tcNo.startsWith("0"))
        return false
    if (!tcNo.matches("[0-9]+".toRegex()))
        return false
    val tcNoArray = tcNo.map { it.toString().toInt() }
    if (tcNoArray[9] != (((7 * (tcNoArray[0] + tcNoArray[2] + tcNoArray[4] + tcNoArray[6]+ tcNoArray[8])) - (tcNoArray[1] + tcNoArray[3]+ tcNoArray[5] + tcNoArray[7])) % 10))
        return false
    var totalFirst10 = 0
    for (x in 0 until 10) {
        totalFirst10 += tcNoArray[x]
    }
    if (tcNoArray[10] != (totalFirst10 % 10))
        return false
    return true
}