import datkt.sodium.* // entire libsodium API
import kotlinx.cinterop.* // exposes types needed for interop

fun main(args: Array<String>) {
  if (0 != sodium_init()) {
    throw Error("Failed to initialize libsodium")
  }
}

import kotlinx.cinterop.*
import datkt.sodium.sodium_init
import datkt.sodium.randombytes_buf
import datkt.sodium.randombytes_random
import datkt.sodium.randombytes_uniform

fun main(args: Array<String>) {
  val rc = sodium_init()

  if (0 != rc) {
    throw Error("sodium_init() != 0")
  }

  println("${randombytes_random()} = randombytes_random()")
  println("${randombytes_uniform(37)} = randombytes_uniform(37)")

  var buffer = ByteArray(16)

  buffer.usePinned { pinned ->
    randombytes_buf(pinned.addressOf(0), buffer.size.convert())
  }

  println("${toHexString(buffer)} = randombytes_buf(ByteArray(16), 16)")
}

val table = "0123456789abcdef".toCharArray()

fun toHexString(bytes: ByteArray): String {
  var output = CharArray(2 * bytes.size)
  for (i in bytes.indices) {
    val j = (bytes[i].toInt() and 0xff).toInt()
    output[2 * i] = table[j ushr 4]
    output[1 + 2 * i] = table[j and 0x0f]
  }
  return String(output)
}

fun crypto_generichash(out: CValuesRef<UByteVar>?,
                       outlen: size_t,
                       `in`: CValuesRef<UByteVar>?,
                       inlen: ULong,
                       key: CValuesRef<UByteVar>?,
                       keylen: size_t): Int;

val buffer = ByteArray(crypto_generichash_BYTES.toInt())
val message = "hello"

buffer.usePinned { pinned ->
  crypto_generichash(
    pinned.addressOf(0) as CValuesRef<UByteVar>,
    buffer.size.convert(),
    message.cstr as CValuesRef<UByteVar>,
    message.length.convert(),
    null, // key
    0 // key size
  )
}