#include <xrpld/app/misc/setup_HashRouter.h>
#include <xrpld/core/Config.h>

#include <xrpl/basics/chrono.h>
#include <xrpl/beast/unit_test/suite.h>
#include <xrpl/core/HashRouter.h>

#include <chrono>
#include <cstdint>
#include <exception>
#include <optional>
#include <set>
#include <type_traits>

namespace xrpl::test {

class HashRouter_test : public beast::unit_test::Suite
{
    static HashRouter::Setup
    getSetup(std::chrono::seconds hold, std::chrono::seconds relay)
    {
        HashRouter::Setup setup;
        setup.holdTime = hold;
        setup.relayTime = relay;
        return setup;
    }

    void
    testNonExpiration()
    {
        testcase("Non-expiration");
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(2s, 1s), stopwatch);

        HashRouterFlags const key1(HashRouterFlags::PRIVATE1);
        HashRouterFlags const key2(HashRouterFlags::PRIVATE2);
        HashRouterFlags const key3(HashRouterFlags::PRIVATE3);

        auto const ukey1 = uint256{static_cast<std::uint64_t>(key1)};
        auto const ukey2 = uint256{static_cast<std::uint64_t>(key2)};
        auto const ukey3 = uint256{static_cast<std::uint64_t>(key3)};

        // t=0
        router.setFlags(ukey1, HashRouterFlags::PRIVATE1);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::PRIVATE1);
        router.setFlags(ukey2, HashRouterFlags::PRIVATE2);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::PRIVATE2);
        // key1 : 0
        // key2 : 0
        // key3: null

        ++stopwatch;

        // Because we are accessing key1 here, it
        // will NOT be expired for another two ticks
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::PRIVATE1);
        // key1 : 1
        // key2 : 0
        // key3 null

        ++stopwatch;

        // t=3
        router.setFlags(ukey3, HashRouterFlags::PRIVATE3);  // force expiration
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::PRIVATE1);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::UNDEFINED);
    }

    void
    testExpiration()
    {
        testcase("Expiration");
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(2s, 1s), stopwatch);

        HashRouterFlags const key1(HashRouterFlags::PRIVATE1);
        HashRouterFlags const key2(HashRouterFlags::PRIVATE2);
        HashRouterFlags const key3(HashRouterFlags::PRIVATE3);
        HashRouterFlags const key4(HashRouterFlags::PRIVATE4);

        auto const ukey1 = uint256{static_cast<std::uint64_t>(key1)};
        auto const ukey2 = uint256{static_cast<std::uint64_t>(key2)};
        auto const ukey3 = uint256{static_cast<std::uint64_t>(key3)};
        auto const ukey4 = uint256{static_cast<std::uint64_t>(key4)};

        BEAST_EXPECT(key1 != key2 && key2 != key3 && key3 != key4);

        // t=0
        router.setFlags(ukey1, HashRouterFlags::BAD);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::BAD);
        // key1 : 0
        // key2 : null
        // key3 : null

        ++stopwatch;

        // Expiration is triggered by insertion,
        // and timestamps are updated on access,
        // so key1 will be expired after the second
        // call to setFlags.
        // t=1

        router.setFlags(ukey2, HashRouterFlags::PRIVATE5);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::BAD);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::PRIVATE5);
        // key1 : 1
        // key2 : 1
        // key3 : null

        ++stopwatch;
        // t=2
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::PRIVATE5);
        // key1 : 1
        // key2 : 2
        // key3 : null

        ++stopwatch;
        // t=3
        router.setFlags(ukey3, HashRouterFlags::BAD);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::UNDEFINED);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::PRIVATE5);
        BEAST_EXPECT(router.getFlags(ukey3) == HashRouterFlags::BAD);
        // key1 : 3
        // key2 : 3
        // key3 : 3

        ++stopwatch;
        // t=4
        // No insertion, no expiration
        router.setFlags(ukey1, HashRouterFlags::SAVED);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::SAVED);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::PRIVATE5);
        BEAST_EXPECT(router.getFlags(ukey3) == HashRouterFlags::BAD);
        // key1 : 4
        // key2 : 4
        // key3 : 4

        ++stopwatch;
        ++stopwatch;

        // t=6
        router.setFlags(ukey4, HashRouterFlags::TRUSTED);
        BEAST_EXPECT(router.getFlags(ukey1) == HashRouterFlags::UNDEFINED);
        BEAST_EXPECT(router.getFlags(ukey2) == HashRouterFlags::UNDEFINED);
        BEAST_EXPECT(router.getFlags(ukey3) == HashRouterFlags::UNDEFINED);
        BEAST_EXPECT(router.getFlags(ukey4) == HashRouterFlags::TRUSTED);
        // key1 : 6
        // key2 : 6
        // key3 : 6
        // key4 : 6
    }

    void
    testSuppression()
    {
        testcase("Suppression");
        // Normal HashRouter
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(2s, 1s), stopwatch);

        uint256 const key1(1);
        uint256 const key2(2);
        uint256 const key3(3);
        uint256 const key4(4);
        BEAST_EXPECT(key1 != key2 && key2 != key3 && key3 != key4);

        HashRouterFlags flags(HashRouterFlags::BAD);  // This value is ignored
        router.addSuppression(key1);
        BEAST_EXPECT(router.addSuppressionPeer(key2, 15));
        BEAST_EXPECT(router.addSuppressionPeer(key3, 20, flags));
        BEAST_EXPECT(flags == HashRouterFlags::UNDEFINED);

        ++stopwatch;

        BEAST_EXPECT(!router.addSuppressionPeer(key1, 2));
        BEAST_EXPECT(!router.addSuppressionPeer(key2, 3));
        BEAST_EXPECT(!router.addSuppressionPeer(key3, 4, flags));
        BEAST_EXPECT(flags == HashRouterFlags::UNDEFINED);
        BEAST_EXPECT(router.addSuppressionPeer(key4, 5));
    }

    void
    testSetFlags()
    {
        testcase("Set Flags");
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(2s, 1s), stopwatch);

        uint256 const key1(1);
        BEAST_EXPECT(router.setFlags(key1, HashRouterFlags::PRIVATE1));
        BEAST_EXPECT(!router.setFlags(key1, HashRouterFlags::PRIVATE1));
        BEAST_EXPECT(router.setFlags(key1, HashRouterFlags::PRIVATE2));
    }

    void
    testRelay()
    {
        testcase("Relay");
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(50s, 1s), stopwatch);

        uint256 const key1(1);

        std::optional<std::set<HashRouter::PeerShortID>> peers;

        peers = router.shouldRelay(key1);
        BEAST_EXPECT(peers && peers->empty());
        router.addSuppressionPeer(key1, 1);
        router.addSuppressionPeer(key1, 3);
        router.addSuppressionPeer(key1, 5);
        // No action, because relayed
        BEAST_EXPECT(!router.shouldRelay(key1));
        // Expire, but since the next search will
        // be for this entry, it will get refreshed
        // instead. However, the relay won't.
        ++stopwatch;
        // Get those peers we added earlier
        peers = router.shouldRelay(key1);
        BEAST_EXPECT(peers && peers->size() == 3);
        router.addSuppressionPeer(key1, 2);
        router.addSuppressionPeer(key1, 4);
        // No action, because relayed
        BEAST_EXPECT(!router.shouldRelay(key1));
        // Expire, but since the next search will
        // be for this entry, it will get refreshed
        // instead. However, the relay won't.
        ++stopwatch;
        // Relay again
        peers = router.shouldRelay(key1);
        BEAST_EXPECT(peers && peers->size() == 2);
        // Expire again
        ++stopwatch;
        // Confirm that peers list is empty.
        peers = router.shouldRelay(key1);
        BEAST_EXPECT(peers && peers->empty());
    }

    void
    testProcess()
    {
        testcase("Process");
        using namespace std::chrono_literals;
        TestStopwatch stopwatch;
        HashRouter router(getSetup(5s, 1s), stopwatch);
        uint256 const key(1);
        HashRouter::PeerShortID const peer = 1;
        HashRouterFlags flags = HashRouterFlags::UNDEFINED;

        BEAST_EXPECT(router.shouldProcess(key, peer, flags, 1s));
        BEAST_EXPECT(!router.shouldProcess(key, peer, flags, 1s));
        ++stopwatch;
        ++stopwatch;
        BEAST_EXPECT(router.shouldProcess(key, peer, flags, 1s));
    }

    void
    testSetup()
    {
        testcase("setup_HashRouter");

        using namespace std::chrono_literals;
        {
            Config const cfg;
            // default
            auto const setup = setupHashRouter(cfg);
            BEAST_EXPECT(setup.holdTime == 300s);
            BEAST_EXPECT(setup.relayTime == 30s);
        }
        {
            Config cfg;
            // non-default
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "600");
            h.set("relay_time", "15");
            auto const setup = setupHashRouter(cfg);
            BEAST_EXPECT(setup.holdTime == 600s);
            BEAST_EXPECT(setup.relayTime == 15s);
        }
        {
            Config cfg;
            // equal
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "400");
            h.set("relay_time", "400");
            auto const setup = setupHashRouter(cfg);
            BEAST_EXPECT(setup.holdTime == 400s);
            BEAST_EXPECT(setup.relayTime == 400s);
        }
        {
            Config cfg;
            // wrong order
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "60");
            h.set("relay_time", "120");
            try
            {
                setupHashRouter(cfg);
                fail();
            }
            catch (std::exception const& e)
            {
                std::string const expected =
                    "HashRouter relay time must be less than or equal to hold "
                    "time";
                BEAST_EXPECT(e.what() == expected);
            }
        }
        {
            Config cfg;
            // too small hold
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "10");
            h.set("relay_time", "120");
            try
            {
                setupHashRouter(cfg);
                fail();
            }
            catch (std::exception const& e)
            {
                std::string const expected =
                    "HashRouter hold time must be at least 12 seconds (the "
                    "approximate validation time for three "
                    "ledgers).";
                BEAST_EXPECT(e.what() == expected);
            }
        }
        {
            Config cfg;
            // too small relay
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "500");
            h.set("relay_time", "6");
            try
            {
                setupHashRouter(cfg);
                fail();
            }
            catch (std::exception const& e)
            {
                std::string const expected =
                    "HashRouter relay time must be at least 8 seconds (the "
                    "approximate validation time for two ledgers).";
                BEAST_EXPECT(e.what() == expected);
            }
        }
        {
            Config cfg;
            // garbage
            auto& h = cfg.section("hashrouter");
            h.set("hold_time", "alice");
            h.set("relay_time", "bob");
            auto const setup = setupHashRouter(cfg);
            // The set function ignores values that don't convert, so the
            // defaults are left unchanged
            BEAST_EXPECT(setup.holdTime == 300s);
            BEAST_EXPECT(setup.relayTime == 30s);
        }
    }

    void
    testFlagsOps()
    {
        testcase("Bitwise Operations");

        using HF = HashRouterFlags;
        using UHF = std::underlying_type_t<HF>;

        HF const f1 = HF::BAD;
        HF const f2 = HF::SAVED;
        HF const combined = f1 | f2;

        BEAST_EXPECT(static_cast<UHF>(combined) == (static_cast<UHF>(f1) | static_cast<UHF>(f2)));

        HF temp = f1;
        temp |= f2;
        BEAST_EXPECT(temp == combined);

        HF const intersect = combined & f1;
        BEAST_EXPECT(intersect == f1);

        HF temp2 = combined;
        temp2 &= f1;
        BEAST_EXPECT(temp2 == f1);

        BEAST_EXPECT(any(f1));
        BEAST_EXPECT(any(f2));
        BEAST_EXPECT(any(combined));
        BEAST_EXPECT(!any(HF::UNDEFINED));
    }

public:
    void
    run() override
    {
        testNonExpiration();
        testExpiration();
        testSuppression();
        testSetFlags();
        testRelay();
        testProcess();
        testSetup();
        testFlagsOps();
    }
};

BEAST_DEFINE_TESTSUITE(HashRouter, app, xrpl);

}  // namespace xrpl::test