package com.android.trisolarisserver.component

internal fun formatAadhaar(value: String): String {
    if (value.length != 12) return value
    return value.chunked(4).joinToString(" ")
}

internal fun isValidAadhaar(value: String): Boolean {
    if (value.length != 12 || !value.all { it.isDigit() }) return false
    var c = 0
    val reversed = value.reversed()
    for (i in reversed.indices) {
        val digit = reversed[i].digitToInt()
        c = aadhaarMultiplication[c][aadhaarPermutation[i % 8][digit]]
    }
    return c == 0
}

private val aadhaarMultiplication = arrayOf(
    intArrayOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9),
    intArrayOf(1, 2, 3, 4, 0, 6, 7, 8, 9, 5),
    intArrayOf(2, 3, 4, 0, 1, 7, 8, 9, 5, 6),
    intArrayOf(3, 4, 0, 1, 2, 8, 9, 5, 6, 7),
    intArrayOf(4, 0, 1, 2, 3, 9, 5, 6, 7, 8),
    intArrayOf(5, 9, 8, 7, 6, 0, 4, 3, 2, 1),
    intArrayOf(6, 5, 9, 8, 7, 1, 0, 4, 3, 2),
    intArrayOf(7, 6, 5, 9, 8, 2, 1, 0, 4, 3),
    intArrayOf(8, 7, 6, 5, 9, 3, 2, 1, 0, 4),
    intArrayOf(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
)
private val aadhaarPermutation = arrayOf(
    intArrayOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9),
    intArrayOf(1, 5, 7, 6, 2, 8, 3, 0, 9, 4),
    intArrayOf(5, 8, 0, 3, 7, 9, 6, 1, 4, 2),
    intArrayOf(8, 9, 1, 6, 0, 4, 3, 5, 2, 7),
    intArrayOf(9, 4, 5, 3, 1, 2, 6, 8, 7, 0),
    intArrayOf(4, 2, 8, 6, 5, 7, 3, 9, 0, 1),
    intArrayOf(2, 7, 9, 3, 8, 0, 6, 4, 1, 5),
    intArrayOf(7, 0, 4, 6, 9, 1, 3, 2, 5, 8)
)