package com.infendro.hash.sha2

import com.infendro.bytearray.addAll
import com.infendro.bytearray.toByteArray
import com.infendro.bytearray.toULongArray
import com.infendro.hash.HashFunction

@Suppress("UNUSED")
object `SHA-384` : HashFunction() {
    override val bytes: Int
        get() = 48

    private val k = arrayOf(
        0x428a2f98d728ae22UL, 0x7137449123ef65cdUL, 0xb5c0fbcfec4d3b2fUL, 0xe9b5dba58189dbbcUL, 0x3956c25bf348b538UL,
        0x59f111f1b605d019UL, 0x923f82a4af194f9bUL, 0xab1c5ed5da6d8118UL, 0xd807aa98a3030242UL, 0x12835b0145706fbeUL,
        0x243185be4ee4b28cUL, 0x550c7dc3d5ffb4e2UL, 0x72be5d74f27b896fUL, 0x80deb1fe3b1696b1UL, 0x9bdc06a725c71235UL,
        0xc19bf174cf692694UL, 0xe49b69c19ef14ad2UL, 0xefbe4786384f25e3UL, 0x0fc19dc68b8cd5b5UL, 0x240ca1cc77ac9c65UL,
        0x2de92c6f592b0275UL, 0x4a7484aa6ea6e483UL, 0x5cb0a9dcbd41fbd4UL, 0x76f988da831153b5UL, 0x983e5152ee66dfabUL,
        0xa831c66d2db43210UL, 0xb00327c898fb213fUL, 0xbf597fc7beef0ee4UL, 0xc6e00bf33da88fc2UL, 0xd5a79147930aa725UL,
        0x06ca6351e003826fUL, 0x142929670a0e6e70UL, 0x27b70a8546d22ffcUL, 0x2e1b21385c26c926UL, 0x4d2c6dfc5ac42aedUL,
        0x53380d139d95b3dfUL, 0x650a73548baf63deUL, 0x766a0abb3c77b2a8UL, 0x81c2c92e47edaee6UL, 0x92722c851482353bUL,
        0xa2bfe8a14cf10364UL, 0xa81a664bbc423001UL, 0xc24b8b70d0f89791UL, 0xc76c51a30654be30UL, 0xd192e819d6ef5218UL,
        0xd69906245565a910UL, 0xf40e35855771202aUL, 0x106aa07032bbd1b8UL, 0x19a4c116b8d2d0c8UL, 0x1e376c085141ab53UL,
        0x2748774cdf8eeb99UL, 0x34b0bcb5e19b48a8UL, 0x391c0cb3c5c95a63UL, 0x4ed8aa4ae3418acbUL, 0x5b9cca4f7763e373UL,
        0x682e6ff3d6b2b8a3UL, 0x748f82ee5defb2fcUL, 0x78a5636f43172f60UL, 0x84c87814a1f0ab72UL, 0x8cc702081a6439ecUL,
        0x90befffa23631e28UL, 0xa4506cebde82bde9UL, 0xbef9a3f7b2c67915UL, 0xc67178f2e372532bUL, 0xca273eceea26619cUL,
        0xd186b8c721c0c207UL, 0xeada7dd6cde0eb1eUL, 0xf57d4f7fee6ed178UL, 0x06f067aa72176fbaUL, 0x0a637dc5a2c898a6UL,
        0x113f9804bef90daeUL, 0x1b710b35131c471bUL, 0x28db77f523047d84UL, 0x32caab7b40c72493UL, 0x3c9ebe0a15c9bebcUL,
        0x431d67c49c100d4cUL, 0x4cc5d4becb3e42b6UL, 0x597f299cfc657e2aUL, 0x5fcb6fab3ad6faecUL, 0x6c44198c4a475817UL,
    )

    override fun hash(
        value: ByteArray,
    ): ByteArray {
        var h0 = 0xcbbb9d5dc1059ed8UL
        var h1 = 0x629a292a367cd507UL
        var h2 = 0x9159015a3070dd17UL
        var h3 = 0x152fecd8f70e5939UL
        var h4 = 0x67332667ffc00b31UL
        var h5 = 0x8eb44a8768581511UL
        var h6 = 0xdb0c2e0d64f98fa7UL
        var h7 = 0x47b5481dbefa4fa4UL
        val ml = value.size.toULong() * 8UL

        val paddedValue = buildList {
            addAll(value)
            add(0x80.toByte())
            while (size % 128 != 120) {
                add(0x00.toByte())
            }
            addAll(ml.toByteArray())
        }

        val chunks = paddedValue
            .chunked(128)
        for (chunk in chunks) {
            val w = buildList {
                addAll(chunk.toULongArray())
                for (i in 16..<80) {
                    val s0 = get(i - 15).rotateRight(1) xor get(i - 15).rotateRight(8) xor (get(i - 15) shr 7)
                    val s1 = get(i - 2).rotateRight(19) xor get(i - 2).rotateRight(61) xor (get(i - 2) shr 6)
                    add(get(i - 16) + s0 + get(i - 7) + s1)
                }
            }

            var a = h0
            var b = h1
            var c = h2
            var d = h3
            var e = h4
            var f = h5
            var g = h6
            var h = h7

            for (i in 0..<80) {
                val s0 = a.rotateRight(28) xor a.rotateRight(34) xor a.rotateRight(39)
                val s1 = e.rotateRight(14) xor e.rotateRight(18) xor e.rotateRight(41)
                val ch = (e and f) xor (e.inv() and g)
                val temp1 = h + s1 + ch + k[i] + w[i]
                val maj = (a and b) xor (a and c) xor (b and c)
                val temp2 = s0 + maj

                h = g
                g = f
                f = e
                e = d + temp1
                d = c
                c = b
                b = a
                a = temp1 + temp2
            }

            h0 += a
            h1 += b
            h2 += c
            h3 += d
            h4 += e
            h5 += f
            h6 += g
            h7 += h
        }

        return byteArrayOf(
            *h0.toByteArray(),
            *h1.toByteArray(),
            *h2.toByteArray(),
            *h3.toByteArray(),
            *h4.toByteArray(),
            *h5.toByteArray(),
        )
    }
}