#include <gtest/gtest.h>

#include "dpf.hpp"

#include "helpers/eval_common_data.hpp"

#include <type_traits>

namespace
{

template <typename A, typename B>
auto recon(const A & a, const B & b)
{
    if constexpr (dpf::is_secret_share_v<std::decay_t<A>>
        && dpf::is_secret_share_v<std::decay_t<B>>)
        return dpf::reconstruct(a, b);
    else
        return a - b;
}

}  // namespace

template <typename T>
struct EvalPointTest : public testing::Test
{
  public:
    using input_type = typename std::tuple_element_t<0, T>;
    using output_type = typename std::tuple_element_t<1, T>;
    using integral_type = dpf::utils::integral_type_from_bitlength_t<dpf::utils::bitlength_of_v<input_type>>;
    using dpf_type = dpf::utils::dpf_type_t<dpf::prg::aes128, dpf::prg::aes128, input_type, output_type>;

  protected:
    EvalPointTest()
      : params{std::get<std::vector<T>>(allParams)},
        range{(std::size_t(1) << std::min(dpf::utils::bitlength_of_v<input_type>, std::size_t(10))-1)-1},
        zero_output{from_integral_type_output(0)}
    { }

    void SetUp() override
    { }

    void TearDown() override
    { }

    input_type get_start(const input_type & x)
    {
        integral_type x_int = to_integral_type(x),
                      min_int = to_integral_type(std::numeric_limits<input_type>::min()),
                      max_int = to_integral_type(std::numeric_limits<input_type>::max()),
                      start_int;
        // set start_int so that the tested range is centered around x_int if possible
        //   use start_int = min_int if x_int smaller than min_int+range
        //   or start_int = max_int-2*range if x_int larger than max_int-range
        // range is selected to be at most 1 less than half the maximum range for input_type
        //   this ensures there are no overflow issues
        // for signed integral types, since the MSB is internally flipped,
        //   needed additional check that x_int was in the correct range for the given
        //   conditionals (note that these added checks are always try for unsigned types)
        if (x_int < min_int + range && x_int >= min_int)
        {
            start_int = min_int;
        }
        else if (x_int > max_int - range && x_int <= max_int)
        {
            start_int = max_int - (range << 1);
        }
        else
        {
            start_int = x_int - range;
        }
        return from_integral_type(start_int);
    }

    template <typename UnaryFunction0, typename UnaryFunction1>
    void assert_wrapper(const input_type & x, const output_type & y,
        UnaryFunction0 f0, UnaryFunction1 f1)
    {
        input_type cur = get_start(x);
        for (std::size_t i = 0; i <= range<<1; ++i, cur = next_domain_point(cur))
        {
            auto y0 = *f0(cur);
            auto y1 = *f1(cur);
            const output_type got = recon(y0, y1);
            if (cur == x)
            {
                ASSERT_EQ(got, y);
            }
            else
            {
                ASSERT_EQ(got, zero_output);
            }
        }
    }

    static constexpr auto to_integral_type = dpf::utils::to_integral_type<input_type>{};
    static constexpr auto from_integral_type = dpf::utils::make_from_integral_value<input_type>{};
    static constexpr auto from_integral_type_output = dpf::utils::make_from_integral_value<output_type>{};

    std::vector<T> params;
    std::size_t range;
    output_type zero_output;
};

TYPED_TEST_SUITE_P(EvalPointTest);

TYPED_TEST_P(EvalPointTest, Basic)
{
    using input_type = typename TestFixture::input_type;

    for (auto [x, y] : this->params)
    {
        auto [dpf0, dpf1] = dpf::make_dpf(x, y);

        this->assert_wrapper(x, y,
            [&dpf0](input_type cur)
            {
                return dpf::eval_point(dpf0, cur);
            },
            [&dpf1](input_type cur)
            {
                return dpf::eval_point(dpf1, cur);
            }
        );
    }
}

TYPED_TEST_P(EvalPointTest, BasicPathMemoizer)
{
    using input_type = typename TestFixture::input_type;

    for (auto [x, y] : this->params)
    {
        auto [dpf0, dpf1] = dpf::make_dpf(x, y);
        using key0_t = std::decay_t<decltype(dpf0)>;
        using key1_t = std::decay_t<decltype(dpf1)>;
        auto memo0 = dpf::make_basic_path_memoizer<key0_t>(),
             memo1 = dpf::make_basic_path_memoizer<key1_t>();

        this->assert_wrapper(x, y,
            [&dpf0, &memo0](input_type cur)
            {
                return dpf::eval_point(dpf0, cur, memo0);
            },
            [&dpf1, &memo1](input_type cur)
            {
                return dpf::eval_point(dpf1, cur, memo1);
            }
        );
    }
}

TYPED_TEST_P(EvalPointTest, NonmemoizingPathMemoizer)
{
    using input_type = typename TestFixture::input_type;

    for (auto [x, y] : this->params)
    {
        auto [dpf0, dpf1] = dpf::make_dpf(x, y);
        using key0_t = std::decay_t<decltype(dpf0)>;
        using key1_t = std::decay_t<decltype(dpf1)>;
        auto memo0 = dpf::make_nonmemoizing_path_memoizer<key0_t>(),
             memo1 = dpf::make_nonmemoizing_path_memoizer<key1_t>();

        this->assert_wrapper(x, y,
            [&dpf0, &memo0](input_type cur)
            {
                return dpf::eval_point(dpf0, cur, memo0);
            },
            [&dpf1, &memo1](input_type cur)
            {
                return dpf::eval_point(dpf1, cur, memo1);
            }
        );
    }
}

REGISTER_TYPED_TEST_SUITE_P(EvalPointTest,
    Basic,
    BasicPathMemoizer,
    NonmemoizingPathMemoizer);
using Types = testing::Types
<
    // base test
    test_type<uint16_t, uint64_t>,

    // test input types
    test_type<int16_t, uint64_t>,
    test_type<uint8_t, uint64_t>,
    test_type<uint64_t, uint64_t>,
    test_type<simde_int128, uint64_t>,
    test_type<simde_uint128, uint64_t>,
    test_type<dpf::bitstring<10>, uint64_t>,
    test_type<dpf::keyword<3, dpf::alphabets::hex>, uint64_t>,
    test_type<dpf::modint<10>, uint64_t>,
    test_type<dpf::xor_wrapper<int16_t>, uint64_t>,
    test_type<dpf::xor_wrapper<uint16_t>, uint64_t>,

    // test output types
    test_type<uint16_t, int64_t>,
    test_type<uint16_t, uint8_t>,
    test_type<uint16_t, simde_int128>,
    test_type<uint16_t, simde_uint128>,
    test_type<uint16_t, dpf::bit>,
    test_type<uint16_t, dpf::bitstring<20, uint8_t>>,
    test_type<uint16_t, dpf::bitstring<150>>,
    test_type<uint16_t, dpf::xor_wrapper<int64_t>>,
    test_type<uint16_t, dpf::xor_wrapper<uint64_t>>,

    // custom types
    test_type<custom_input_type, uint64_t>,
    test_type<uint16_t, custom_output_type_small>,
    test_type<uint16_t, custom_output_type_large_plus_minus>,
    test_type<uint16_t, custom_output_type_large_xor>
>;
INSTANTIATE_TYPED_TEST_SUITE_P(EvalPointTestInstantiation, EvalPointTest, Types);