/*
 * Copyright (c) 2022, the SerenityOS developers.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <LibTest/TestCase.h>

#include <AK/Endian.h>
#include <AK/IPv6Address.h>

TEST_CASE(should_default_contructor_with_0s)
{
    constexpr IPv6Address addr {};

    static_assert(addr.is_zero());

    EXPECT(addr.is_zero());
}

TEST_CASE(should_construct_from_c_array)
{
    constexpr auto addr = [] {
        u8 const a[16] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
        return IPv6Address(a);
    }();

    static_assert(!addr.is_zero());

    EXPECT(!addr.is_zero());
}

TEST_CASE(should_get_groups_by_index)
{
    constexpr IPv6Address addr({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 });

    static_assert(0x102 == addr[0]);
    static_assert(0x304 == addr[1]);
    static_assert(0x506 == addr[2]);
    static_assert(0x708 == addr[3]);
    static_assert(0x90a == addr[4]);
    static_assert(0xb0c == addr[5]);
    static_assert(0xd0e == addr[6]);
    static_assert(0xf10 == addr[7]);

    EXPECT_EQ(0x102, addr[0]);
    EXPECT_EQ(0x304, addr[1]);
    EXPECT_EQ(0x506, addr[2]);
    EXPECT_EQ(0x708, addr[3]);
    EXPECT_EQ(0x90a, addr[4]);
    EXPECT_EQ(0xb0c, addr[5]);
    EXPECT_EQ(0xd0e, addr[6]);
    EXPECT_EQ(0xf10, addr[7]);
}

TEST_CASE(should_convert_to_string)
{
    auto to_string = [&](IPv6Address::in6_addr_t const& data) -> String {
        return MUST(IPv6Address(data).to_string());
    };

    EXPECT_EQ("102:304:506:708:90a:b0c:d0e:f10"sv, to_string({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
    EXPECT_EQ("::"sv, MUST(IPv6Address().to_string()));
    EXPECT_EQ("::1"sv, to_string({ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }));
    EXPECT_EQ("1::"sv, to_string({ 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }));
    EXPECT_EQ("102:0:506:708:900::10"sv, to_string({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 16 }));
    EXPECT_EQ("102:0:506:708:900::"sv, to_string({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 0 }));
    EXPECT_EQ("::304:506:708:90a:b0c:d0e:f10"sv, to_string({ 0, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
    EXPECT_EQ("102:304::708:90a:b0c:d0e:f10"sv, to_string({ 1, 2, 3, 4, 0, 0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
}

TEST_CASE(should_make_ipv6_address_from_string)
{
    EXPECT(!IPv6Address::from_string(":::"sv).has_value());
    EXPECT(!IPv6Address::from_string(":::1"sv).has_value());
    EXPECT(!IPv6Address::from_string("1:::"sv).has_value());
    EXPECT_EQ(IPv6Address::from_string("102:304:506:708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
    EXPECT_EQ(IPv6Address::from_string("::"sv).value(), IPv6Address());
    EXPECT_EQ(IPv6Address::from_string("::1"sv).value(), IPv6Address({ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }));
    EXPECT_EQ(IPv6Address::from_string("1::"sv).value(), IPv6Address({ 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }));
    EXPECT_EQ(IPv6Address::from_string("102:0:506:708:900::10"sv).value(), IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 16 }));
    EXPECT_EQ(IPv6Address::from_string("102:0:506:708:900::"sv).value(), IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 0 }));
    EXPECT_EQ(IPv6Address::from_string("::304:506:708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 0, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
    EXPECT_EQ(IPv6Address::from_string("102:304::708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 1, 2, 3, 4, 0, 0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
}

TEST_CASE(ipv4_mapped_ipv6)
{
    auto ipv4_address_to_map = IPv4Address::from_string("192.168.0.1"sv).release_value();
    IPv6Address mapped_address(ipv4_address_to_map);
    EXPECT(mapped_address.is_ipv4_mapped());
    EXPECT_EQ(ipv4_address_to_map, mapped_address.ipv4_mapped_address().value());
    EXPECT_EQ("::ffff:192.168.0.1"sv, MUST(mapped_address.to_string()));
    EXPECT_EQ(IPv4Address(192, 168, 1, 9), IPv6Address::from_string("::FFFF:192.168.1.9"sv).value().ipv4_mapped_address().value());
    EXPECT(!IPv6Address::from_string("::abcd:192.168.1.9"sv).has_value());
}

TEST_CASE(should_make_empty_optional_from_bad_string)
{
    auto const addr = IPv6Address::from_string("bad string"sv);

    EXPECT(!addr.has_value());
}

TEST_CASE(should_make_empty_optional_from_out_of_range_values)
{
    auto const addr = IPv6Address::from_string("::10000"sv);

    EXPECT(!addr.has_value());
}

TEST_CASE(should_only_compare_bytes_from_address)
{
    constexpr IPv6Address addr_a({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 });
    constexpr IPv6Address addr_b({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 });
    constexpr IPv6Address addr_c({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 });

    static_assert(addr_a != addr_b);
    static_assert(addr_a == addr_a);
    static_assert(addr_b == addr_c);

    EXPECT(addr_a != addr_b);
    EXPECT(addr_a == addr_a);
    EXPECT(addr_b == addr_c);
}

TEST_CASE(subnets)
{
    constexpr IPv6Address loopback({ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 });
    constexpr IPv6Address lla({ 0xfe, 0x80, 0, 0, 0, 0, 0, 0, 0xab, 0xcd, 0xef, 0x8b, 0xcd, 0xaf, 0xf2, 0xd0 });
    constexpr IPv6Address ula({ 0xfd, 0x00, 0, 0, 0, 0, 0, 0, 0x65, 0xc9, 0xae, 0x8b, 0xcd, 0xaf, 0xf2, 0xd0 });
    constexpr IPv6Address documentation({ 0x20, 0x01, 0xdb, 0x08, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x42 });
    constexpr IPv6Address broadcast({ 0xff, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 });
    constexpr IPv6Address all_routers({ 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 });

    EXPECT(loopback.is_loopback());
    EXPECT(!all_routers.is_loopback());

    EXPECT(lla.is_link_local());
    EXPECT(ula.is_unique_local());
    EXPECT(!lla.is_unique_local());
    EXPECT(!ula.is_link_local());
    EXPECT(!documentation.is_unique_local());
    EXPECT(!documentation.is_link_local());
    EXPECT(!broadcast.is_unique_local());
    EXPECT(!broadcast.is_link_local());
    EXPECT(!all_routers.is_unique_local());
    EXPECT(!all_routers.is_link_local());

    EXPECT(lla.is_unicast());
    EXPECT(ula.is_unicast());
    EXPECT(loopback.is_unicast());
    EXPECT(documentation.is_unicast());
    EXPECT(broadcast.is_multicast());
    EXPECT(all_routers.is_multicast());

    EXPECT(!loopback.is_in_subnet(lla, 64));
    EXPECT(lla.is_in_subnet(lla.network(64), 64));
    EXPECT(ula.is_in_subnet(ula.network(128), 128));
    EXPECT(loopback.is_in_subnet(loopback, 128));
    EXPECT(documentation.is_in_subnet(documentation, 128));
    EXPECT(broadcast.is_in_subnet(broadcast, 128));
    EXPECT(all_routers.is_in_subnet(all_routers, 128));
    EXPECT(!ula.is_in_subnet(lla, 64));
    // Not sensible networks per IETF!
    EXPECT(lla.is_in_subnet(ula.network(4), 4));
    EXPECT(broadcast.is_in_subnet(all_routers.network(12), 12));
    EXPECT(!documentation.is_in_subnet(lla, 4));
}