package com.infendro.random.prng

import com.infendro.bytes.bytearray.toLong
import com.infendro.hash.sha2.`SHA-256`
import com.infendro.random.PRNG
import kotlin.properties.Delegates.notNull

class LCG : PRNG() {
    private val a: Long = 25214903917L
    private val c: Long = 11L
    private val mask: Long = (1L shl 48) - 1

    private var x: Long by notNull()

    override fun seed(seed: ByteArray) {
        x = `SHA-256`.hash(seed).toLong() and mask
    }

    override fun generate(): Int {
        x = (a * x + c) and mask
        return (x ushr 16).toInt()
    }
}