import
  std/[times, random],
  bearssl/rand,
  libp2p/crypto/crypto
import
  ../../../waku/v2/utils/time


# Time

proc now*(): Timestamp =
  getNanosecondTime(getTime().toUnixFloat())

proc ts*(offset=0, origin=now()): Timestamp =
  origin + getNanosecondTime(offset)


## Randomization

proc randomize*() =
  ## Initializes the default random number generator with the given seed.
  ## From: https://nim-lang.org/docs/random.html#randomize,int64
  let now = getTime()
  randomize(now.toUnix() * 1_000_000_000 + now.nanosecond)


## RNG
# Copied from here: https://github.com/status-im/nim-libp2p/blob/d522537b19a532bc4af94fcd146f779c1f23bad0/tests/helpers.nim#L28

type Rng = object
    rng: ref HmacDrbgContext

# Typically having a module variable is considered bad design. This case should
# be considered as an exception and it should be used only in the tests.
var rngVar: Rng

proc getRng(): ref HmacDrbgContext =
  # TODO: if `rngVar` is a threadvar like it should be, there are random and
  #      spurious compile failures on mac - this is not gcsafe but for the
  #      purpose of the tests, it's ok as long as we only use a single thread
  {.gcsafe.}:
    if rngVar.rng.isNil():
      rngVar.rng = crypto.newRng()

    rngVar.rng


template rng*(): ref HmacDrbgContext = getRng()