#include <xrpl/basics/Buffer.h>
#include <xrpl/basics/Slice.h>
#include <xrpl/beast/unit_test/suite.h>

#include <cstddef>
#include <cstdint>
#include <cstring>
#include <type_traits>
#include <utility>

namespace xrpl::test {

struct Buffer_test : beast::unit_test::Suite
{
    static bool
    sane(Buffer const& b)
    {
        if (b.empty())
            return b.data() == nullptr;

        return b.data() != nullptr;
    }

    void
    run() override
    {
        std::uint8_t const data[] = {0xa8, 0xa1, 0x38, 0x45, 0x23, 0xec, 0xe4, 0x23,
                                     0x71, 0x6d, 0x2a, 0x18, 0xb4, 0x70, 0xcb, 0xf5,
                                     0xac, 0x2d, 0x89, 0x4d, 0x19, 0x9c, 0xf0, 0x2c,
                                     0x15, 0xd1, 0xf9, 0x9b, 0x66, 0xd2, 0x30, 0xd3};

        Buffer const b0;
        BEAST_EXPECT(sane(b0));
        BEAST_EXPECT(b0.empty());

        Buffer b1{0};
        BEAST_EXPECT(sane(b1));
        BEAST_EXPECT(b1.empty());
        std::memcpy(b1.alloc(16), data, 16);
        BEAST_EXPECT(sane(b1));
        BEAST_EXPECT(!b1.empty());
        BEAST_EXPECT(b1.size() == 16);

        Buffer b2{b1.size()};
        BEAST_EXPECT(sane(b2));
        BEAST_EXPECT(!b2.empty());
        BEAST_EXPECT(b2.size() == b1.size());
        std::memcpy(b2.data(), data + 16, 16);

        Buffer b3{data, sizeof(data)};
        BEAST_EXPECT(sane(b3));
        BEAST_EXPECT(!b3.empty());
        BEAST_EXPECT(b3.size() == sizeof(data));
        BEAST_EXPECT(std::memcmp(b3.data(), data, b3.size()) == 0);

        // Check equality and inequality comparisons
        BEAST_EXPECT(b0 == b0);
        BEAST_EXPECT(b0 != b1);
        BEAST_EXPECT(b1 == b1);
        BEAST_EXPECT(b1 != b2);
        BEAST_EXPECT(b2 != b3);

        // Check copy constructors and copy assignments:
        {
            testcase("Copy Construction / Assignment");

            Buffer x{b0};
            BEAST_EXPECT(x == b0);
            BEAST_EXPECT(sane(x));
            Buffer y{b1};
            BEAST_EXPECT(y == b1);
            BEAST_EXPECT(sane(y));
            x = b2;
            BEAST_EXPECT(x == b2);
            BEAST_EXPECT(sane(x));
            x = y;
            BEAST_EXPECT(x == y);
            BEAST_EXPECT(sane(x));
            y = b3;
            BEAST_EXPECT(y == b3);
            BEAST_EXPECT(sane(y));
            x = b0;
            BEAST_EXPECT(x == b0);
            BEAST_EXPECT(sane(x));
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wself-assign-overloaded"
#endif

            x = x;
            BEAST_EXPECT(x == b0);
            BEAST_EXPECT(sane(x));
            y = y;
            BEAST_EXPECT(y == b3);
            BEAST_EXPECT(sane(y));

#if defined(__clang__)
#pragma clang diagnostic pop
#endif
        }

        // Check move constructor & move assignments:
        {
            testcase("Move Construction / Assignment");

            static_assert(std::is_nothrow_move_constructible_v<Buffer>);
            static_assert(std::is_nothrow_move_assignable_v<Buffer>);

            {  // Move-construct from empty buf
                Buffer x;
                Buffer const y{std::move(x)};
                BEAST_EXPECT(sane(x));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(x.empty());  // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(sane(y));
                BEAST_EXPECT(y.empty());
                BEAST_EXPECT(x == y);  // NOLINT(bugprone-use-after-move)
            }

            {  // Move-construct from non-empty buf
                Buffer x{b1};
                Buffer const y{std::move(x)};
                BEAST_EXPECT(sane(x));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(x.empty());  // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(sane(y));
                BEAST_EXPECT(y == b1);
            }

            {  // Move assign empty buf to empty buf
                Buffer x;
                Buffer y;

                x = std::move(y);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.empty());
                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
            }

            {  // Move assign non-empty buf to empty buf
                Buffer x;
                Buffer y{b1};

                x = std::move(y);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x == b1);
                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
            }

            {  // Move assign empty buf to non-empty buf
                Buffer x{b1};
                Buffer y;

                x = std::move(y);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.empty());
                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
            }

            {  // Move assign non-empty buf to non-empty buf
                Buffer x{b1};
                Buffer y{b2};
                Buffer z{b3};

                x = std::move(y);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(!x.empty());
                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)

                x = std::move(z);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(!x.empty());
                BEAST_EXPECT(sane(z));    // NOLINT(bugprone-use-after-move)
                BEAST_EXPECT(z.empty());  // NOLINT(bugprone-use-after-move)
            }
        }

        {
            testcase("Slice Conversion / Construction / Assignment");

            Buffer w{static_cast<Slice>(b0)};
            BEAST_EXPECT(sane(w));
            BEAST_EXPECT(w == b0);

            Buffer x{static_cast<Slice>(b1)};
            BEAST_EXPECT(sane(x));
            BEAST_EXPECT(x == b1);

            Buffer y{static_cast<Slice>(b2)};
            BEAST_EXPECT(sane(y));
            BEAST_EXPECT(y == b2);

            Buffer z{static_cast<Slice>(b3)};
            BEAST_EXPECT(sane(z));
            BEAST_EXPECT(z == b3);

            // Assign empty slice to empty buffer
            w = static_cast<Slice>(b0);
            BEAST_EXPECT(sane(w));
            BEAST_EXPECT(w == b0);

            // Assign non-empty slice to empty buffer
            w = static_cast<Slice>(b1);
            BEAST_EXPECT(sane(w));
            BEAST_EXPECT(w == b1);

            // Assign non-empty slice to non-empty buffer
            x = static_cast<Slice>(b2);
            BEAST_EXPECT(sane(x));
            BEAST_EXPECT(x == b2);

            // Assign non-empty slice to non-empty buffer
            y = static_cast<Slice>(z);
            BEAST_EXPECT(sane(y));
            BEAST_EXPECT(y == z);

            // Assign empty slice to non-empty buffer:
            z = static_cast<Slice>(b0);
            BEAST_EXPECT(sane(z));
            BEAST_EXPECT(z == b0);
        }

        {
            testcase("Allocation, Deallocation and Clearing");

            auto test = [this](Buffer const& b, std::size_t i) {
                Buffer x{b};

                // Try to allocate some number of bytes, possibly
                // zero (which means clear) and sanity check
                x(i);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.size() == i);
                BEAST_EXPECT((x.data() == nullptr) == (i == 0));

                // Try to allocate some more data (always non-zero)
                x(i + 1);
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.size() == i + 1);
                BEAST_EXPECT(x.data() != nullptr);

                // Try to clear:
                x.clear();
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.empty());
                BEAST_EXPECT(x.data() == nullptr);

                // Try to clear again:
                x.clear();
                BEAST_EXPECT(sane(x));
                BEAST_EXPECT(x.empty());
                BEAST_EXPECT(x.data() == nullptr);
            };

            for (std::size_t i = 0; i < 16; ++i)
            {
                test(b0, i);
                test(b1, i);
            }
        }
    }
};

BEAST_DEFINE_TESTSUITE(Buffer, basics, xrpl);

}  // namespace xrpl::test