# Constantine
# Copyright (c) 2018-2019    Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

import
  # Standard library
  std/[unittest, times],
  # Internals
  ../constantine/config/[common, curves],
  ../constantine/arithmetic,
  ../constantine/io/io_bigints,
  ../constantine/elliptic/[ec_weierstrass_affine, ec_weierstrass_projective, ec_scalar_mul],
  # Test utilities
  ../helpers/prng_unsafe,
  ./support/ec_reference_scalar_mult,
  ./t_ec_template

const
  Iters = 128
  ItersMul = Iters div 4

run_EC_mul_sanity_tests(
    ec = ECP_SWei_Proj[Fp[BN254_Snarks]],
    ItersMul = ItersMul,
    moduleName = "test_ec_weierstrass_projective_g1_mul_sanity_" & $BN254_Snarks
  )

run_EC_mul_sanity_tests(
    ec = ECP_SWei_Proj[Fp[BLS12_381]],
    ItersMul = ItersMul,
    moduleName = "test_ec_weierstrass_projective_g1_mul_sanity_" & $BLS12_381
  )


test "EC mul [Order]P == Inf":
  var rng: RngState
  let seed = uint32(getTime().toUnix() and (1'i64 shl 32 - 1)) # unixTime mod 2^32
  rng.seed(seed)
  echo "test_ec_weierstrass_projective_g1_mul_sanity_extra_curve_order_mul_sanity xoshiro512** seed: ", seed

  proc test(EC: typedesc, bits: static int, randZ: static bool) =
    for _ in 0 ..< ItersMul:
      when randZ:
        let a = rng.random_unsafe_with_randZ(EC)
      else:
        let a = rng.random_unsafe(EC)

      let exponent = EC.F.C.getCurveOrder()
      var exponentCanonical{.noInit.}: array[(bits+7) div 8, byte]
      exponentCanonical.exportRawUint(exponent, bigEndian)

      var
        impl = a
        reference = a
        scratchSpace{.noInit.}: array[1 shl 4, EC]

      impl.scalarMulGeneric(exponentCanonical, scratchSpace)
      reference.unsafe_ECmul_double_add(exponentCanonical)

      check:
        bool(impl.isInf())
        bool(reference.isInf())

  test(ECP_SWei_Proj[Fp[BN254_Snarks]], bits = BN254_Snarks.getCurveOrderBitwidth(), randZ = false)
  test(ECP_SWei_Proj[Fp[BN254_Snarks]], bits = BN254_Snarks.getCurveOrderBitwidth(), randZ = true)
  # TODO: BLS12 is using a subgroup of order "r" such as r*h = CurveOrder
  #       with h the curve cofactor
  #       instead of the full group
  # test(Fp[BLS12_381], bits = BLS12_381.getCurveOrderBitwidth(), randZ = false)
  # test(Fp[BLS12_381], bits = BLS12_381.getCurveOrderBitwidth(), randZ = true)