#include <test/jtx.h>

#include <xrpld/app/consensus/RCLValidations.h>

#include <xrpl/basics/base_uint.h>
#include <xrpl/beast/unit_test.h>
#include <xrpl/ledger/Ledger.h>

namespace xrpl {
namespace test {

class RCLValidations_test : public beast::unit_test::suite
{
    void
    testChangeTrusted()
    {
        testcase("Change validation trusted status");
        auto keys = randomKeyPair(KeyType::secp256k1);
        auto v = std::make_shared<STValidation>(
            xrpl::NetClock::time_point{},
            keys.first,
            keys.second,
            calcNodeID(keys.first),
            [&](STValidation& v) { v.setFieldU32(sfLedgerSequence, 123456); });

        BEAST_EXPECT(v->isTrusted());
        v->setUntrusted();
        BEAST_EXPECT(!v->isTrusted());

        RCLValidation rcv{v};
        BEAST_EXPECT(!rcv.trusted());
        rcv.setTrusted();
        BEAST_EXPECT(rcv.trusted());
        rcv.setUntrusted();
        BEAST_EXPECT(!rcv.trusted());
    }

    void
    testRCLValidatedLedger()
    {
        testcase("RCLValidatedLedger ancestry");

        using Seq = RCLValidatedLedger::Seq;
        using ID = RCLValidatedLedger::ID;

        // This tests RCLValidatedLedger properly implements the type
        // requirements of a LedgerTrie ledger, with its added behavior that
        // only the 256 prior ledger hashes are available to determine ancestry.
        Seq const maxAncestors = 256;

        //----------------------------------------------------------------------
        // Generate two ledger histories that agree on the first maxAncestors
        // ledgers, then diverge.

        std::vector<std::shared_ptr<Ledger const>> history;

        jtx::Env env(*this);
        Config config;
        auto prev = std::make_shared<Ledger const>(
            create_genesis,
            Rules{config.features},
            config.FEES.toFees(),
            std::vector<uint256>{},
            env.app().getNodeFamily());
        history.push_back(prev);
        for (auto i = 0; i < ((2 * maxAncestors) + 1); ++i)
        {
            auto next = std::make_shared<Ledger>(*prev, env.app().timeKeeper().closeTime());
            next->updateSkipList();
            history.push_back(next);
            prev = next;
        }

        // altHistory agrees with first half of regular history
        Seq const diverge = history.size() / 2;
        std::vector<std::shared_ptr<Ledger const>> altHistory(
            history.begin(), history.begin() + diverge);
        // advance clock to get new ledgers
        using namespace std::chrono_literals;
        env.timeKeeper().set(env.timeKeeper().now() + 1200s);
        prev = altHistory.back();
        bool forceHash = true;
        while (altHistory.size() < history.size())
        {
            auto next = std::make_shared<Ledger>(*prev, env.app().timeKeeper().closeTime());
            // Force a different hash on the first iteration
            next->updateSkipList();
            BEAST_EXPECT(next->read(keylet::fees()));
            if (forceHash)
            {
                next->setImmutable();
                forceHash = false;
            }

            altHistory.push_back(next);
            prev = next;
        }

        //----------------------------------------------------------------------

        // Empty ledger
        {
            RCLValidatedLedger a{RCLValidatedLedger::MakeGenesis{}};
            BEAST_EXPECT(a.seq() == Seq{0});
            BEAST_EXPECT(a[Seq{0}] == ID{0});
            BEAST_EXPECT(a.minSeq() == Seq{0});
        }

        // Full history ledgers
        {
            std::shared_ptr<Ledger const> ledger = history.back();
            RCLValidatedLedger a{ledger, env.journal};
            BEAST_EXPECT(a.seq() == ledger->header().seq);
            BEAST_EXPECT(a.minSeq() == a.seq() - maxAncestors);
            // Ensure the ancestral 256 ledgers have proper ID
            for (Seq s = a.seq(); s > 0; s--)
            {
                if (s >= a.minSeq())
                {
                    BEAST_EXPECT(a[s] == history[s - 1]->header().hash);
                }
                else
                {
                    BEAST_EXPECT(a[s] == ID{0});
                }
            }
        }

        // Mismatch tests

        // Empty with non-empty
        {
            RCLValidatedLedger a{RCLValidatedLedger::MakeGenesis{}};

            for (auto ledger : {history.back(), history[maxAncestors - 1]})
            {
                RCLValidatedLedger b{ledger, env.journal};
                BEAST_EXPECT(mismatch(a, b) == 1);
                BEAST_EXPECT(mismatch(b, a) == 1);
            }
        }
        // Same chains, different seqs
        {
            RCLValidatedLedger a{history.back(), env.journal};
            for (Seq s = a.seq(); s > 0; s--)
            {
                RCLValidatedLedger b{history[s - 1], env.journal};
                if (s >= a.minSeq())
                {
                    BEAST_EXPECT(mismatch(a, b) == b.seq() + 1);
                    BEAST_EXPECT(mismatch(b, a) == b.seq() + 1);
                }
                else
                {
                    BEAST_EXPECT(mismatch(a, b) == Seq{1});
                    BEAST_EXPECT(mismatch(b, a) == Seq{1});
                }
            }
        }
        // Different chains, same seqs
        {
            // Alt history diverged at history.size()/2
            for (Seq s = 1; s < history.size(); ++s)
            {
                RCLValidatedLedger a{history[s - 1], env.journal};
                RCLValidatedLedger b{altHistory[s - 1], env.journal};

                BEAST_EXPECT(a.seq() == b.seq());
                if (s <= diverge)
                {
                    BEAST_EXPECT(a[a.seq()] == b[b.seq()]);
                    BEAST_EXPECT(mismatch(a, b) == a.seq() + 1);
                    BEAST_EXPECT(mismatch(b, a) == a.seq() + 1);
                }
                else
                {
                    BEAST_EXPECT(a[a.seq()] != b[b.seq()]);
                    BEAST_EXPECT(mismatch(a, b) == diverge + 1);
                    BEAST_EXPECT(mismatch(b, a) == diverge + 1);
                }
            }
        }
        // Different chains, different seqs
        {
            // Compare around the divergence point
            RCLValidatedLedger a{history[diverge], env.journal};
            for (Seq offset = diverge / 2; offset < 3 * diverge / 2; ++offset)
            {
                RCLValidatedLedger b{altHistory[offset - 1], env.journal};
                if (offset <= diverge)
                {
                    BEAST_EXPECT(mismatch(a, b) == b.seq() + 1);
                }
                else
                {
                    BEAST_EXPECT(mismatch(a, b) == diverge + 1);
                }
            }
        }
    }

    void
    testLedgerTrieRCLValidatedLedger()
    {
        testcase("RCLValidatedLedger LedgerTrie");

        // This test exposes an issue with the limited 256
        // ancestor hash design of RCLValidatedLedger.
        // There is only a single chain of validated ledgers
        // but the 256 gap causes a "split" in the LedgerTrie
        // due to the lack of ancestry information for a later ledger.
        // This exposes a bug in which we are unable to remove
        // support for a ledger hash which is already in the trie.

        using Seq = RCLValidatedLedger::Seq;

        // Max known ancestors for each ledger
        Seq const maxAncestors = 256;
        std::vector<std::shared_ptr<Ledger const>> history;

        // Generate a chain of 256 + 10 ledgers
        jtx::Env env(*this);
        auto& j = env.journal;
        Config config;
        auto prev = std::make_shared<Ledger const>(
            create_genesis,
            Rules{config.features},
            config.FEES.toFees(),
            std::vector<uint256>{},
            env.app().getNodeFamily());
        history.push_back(prev);
        for (auto i = 0; i < (maxAncestors + 10); ++i)
        {
            auto next = std::make_shared<Ledger>(*prev, env.app().timeKeeper().closeTime());
            next->updateSkipList();
            history.push_back(next);
            prev = next;
        }

        LedgerTrie<RCLValidatedLedger> trie;

        // First, create the single branch trie, with ledgers
        // separated by exactly 256 ledgers
        auto ledg_002 = RCLValidatedLedger{history[1], j};
        auto ledg_258 = RCLValidatedLedger{history[257], j};
        auto ledg_259 = RCLValidatedLedger{history[258], j};

        trie.insert(ledg_002);
        trie.insert(ledg_258, 4);
        // trie.dump(std::cout);
        // 000000[0,1)(T:0,B:5)
        //                     |-AB868A..36C8[1,3)(T:1,B:5)
        //                                                 |-AB868A..37C8[3,259)(T:4,B:4)
        BEAST_EXPECT(trie.tipSupport(ledg_002) == 1);
        BEAST_EXPECT(trie.branchSupport(ledg_002) == 5);
        BEAST_EXPECT(trie.tipSupport(ledg_258) == 4);
        BEAST_EXPECT(trie.branchSupport(ledg_258) == 4);

        // Move three of the s258 ledgers to s259, which splits the trie
        // due to the 256 ancestry limit
        BEAST_EXPECT(trie.remove(ledg_258, 3));
        trie.insert(ledg_259, 3);
        trie.getPreferred(1);
        // trie.dump(std::cout);
        // 000000[0,1)(T:0,B:5)
        //                     |-AB868A..37C9[1,260)(T:3,B:3)
        //                     |-AB868A..36C8[1,3)(T:1,B:2)
        //                                                 |-AB868A..37C8[3,259)(T:1,B:1)
        BEAST_EXPECT(trie.tipSupport(ledg_002) == 1);
        BEAST_EXPECT(trie.branchSupport(ledg_002) == 2);
        BEAST_EXPECT(trie.tipSupport(ledg_258) == 1);
        BEAST_EXPECT(trie.branchSupport(ledg_258) == 1);
        BEAST_EXPECT(trie.tipSupport(ledg_259) == 3);
        BEAST_EXPECT(trie.branchSupport(ledg_259) == 3);

        // The last call to trie.getPreferred cycled the children of the root
        // node to make the new branch the first child (since it has support 3)
        // then verify the remove call works
        // past bug: remove had assumed the first child of a node in the trie
        //      which matches is the *only* child in the trie which matches.
        //      This is **NOT** true with the limited 256 ledger ancestry
        //      quirk of RCLValidation and prevents deleting the old support
        //      for ledger 257

        BEAST_EXPECT(trie.remove(RCLValidatedLedger{history[257], env.journal}, 1));
        trie.insert(RCLValidatedLedger{history[258], env.journal}, 1);
        trie.getPreferred(1);
        // trie.dump(std::cout);
        // 000000[0,1)(T:0,B:5)
        //                      |-AB868A..37C9[1,260)(T:4,B:4)
        //                      |-AB868A..36C8[1,3)(T:1,B:1)
        BEAST_EXPECT(trie.tipSupport(ledg_002) == 1);
        BEAST_EXPECT(trie.branchSupport(ledg_002) == 1);
        BEAST_EXPECT(trie.tipSupport(ledg_258) == 0);
        // 258 no longer lives on a tip in the tree, BUT it is an ancestor
        // of 259 which is a tip and therefore gets it's branchSupport value
        // implicitly
        BEAST_EXPECT(trie.branchSupport(ledg_258) == 4);
        BEAST_EXPECT(trie.tipSupport(ledg_259) == 4);
        BEAST_EXPECT(trie.branchSupport(ledg_259) == 4);
    }

public:
    void
    run() override
    {
        testChangeTrusted();
        testRCLValidatedLedger();
        testLedgerTrieRCLValidatedLedger();
    }
};

BEAST_DEFINE_TESTSUITE(RCLValidations, app, xrpl);

}  // namespace test
}  // namespace xrpl
