// SPDX-License-Identifier: MPL-2.0
#include "sequa/core/sim/rng.hpp"

#include <doctest/doctest.h>

#include <array>
#include <cstdint>

using sequa::core::sim::Pcg32;

TEST_CASE("Pcg32 : sorties de reference de pcg32-demo (graine 42, flux 54)")
{
    Pcg32 rng(42, 54);
    const std::array<std::uint32_t, 6> expected{0xa15c02b7u, 0x7b47f409u, 0xba1d3330u,
                                                0x83d2f293u, 0xbfa4784bu, 0xcbed606eu};
    for (const std::uint32_t value : expected) {
        CHECK(rng.next() == value);
    }
}

// Pas de « ; » dans les noms de tests : CMake les lit comme séparateurs de liste.
TEST_CASE("Pcg32 : meme graine meme suite, graine differente suite differente")
{
    Pcg32 a(7, 1);
    Pcg32 b(7, 1);
    Pcg32 c(8, 1);
    bool any_difference = false;
    for (int i = 0; i < 100; ++i) {
        const std::uint32_t va = a.next();
        CHECK(va == b.next());
        any_difference = any_difference || va != c.next();
    }
    CHECK(any_difference);
}

TEST_CASE("Pcg32 : bounded et range restent dans leurs bornes")
{
    Pcg32 rng(123, 9);
    for (int i = 0; i < 10'000; ++i) {
        CHECK(rng.bounded(10) < 10u);
        const std::int32_t v = rng.range(-5, 5);
        CHECK(v >= -5);
        CHECK(v <= 5);
    }
    CHECK(rng.range(3, 3) == 3);
}