//
// Created by erki on 29.04.21.
//

#include <catch2/catch.hpp>

#include "utility_rand.hpp"

TEST_CASE("rand32 is deterministic.", "[utility],[rand]")
{
  const std::uint32_t original_state = 34;
  std::uint32_t state = original_state;
  std::vector<std::uint32_t> generated;

  for (int i = 0; i < 10; i++)
  {
    generated.push_back(Utility::rand32(state));
  }

  std::uint32_t new_state = original_state;
  for (int i = 0; i < 10; i++)
  {
    REQUIRE(generated[i] == Utility::rand32(new_state));
  }
}

TEST_CASE("rand64 is deterministic.", "[utility],[rand]")
{
  const std::uint64_t original_state = 10e4;
  std::uint64_t state = original_state;
  std::vector<std::uint64_t> generated;

  for (int i = 0; i < 10; i++)
  {
    generated.push_back(Utility::rand64(state));
  }

  std::uint64_t new_state = original_state;
  for (int i = 0; i < 10; i++)
  {
    REQUIRE(generated[i] == Utility::rand64(new_state));
  }
}

TEST_CASE("rand and srand are deterministic", "[utility],[rand]")
{
  const std::uint32_t original_state = 34;

  Utility::srand(original_state);
  std::vector<std::uint32_t> generated;

  for (int i = 0; i < 10; i++)
  {
    generated.push_back(Utility::rand());
  }

  Utility::srand(original_state);
  for (int i = 0; i < 10; i++)
  {
    REQUIRE(generated[i] == Utility::rand());
  }
}