refactor: Convert ChainstateRole enum to struct

diff --git a/src/bench/wallet_create_tx.cpp b/src/bench/wallet_create_tx.cpp
index 7fb535f4..73ad0e7e 100644
--- a/src/bench/wallet_create_tx.cpp
+++ b/src/bench/wallet_create_tx.cpp
@@ -11,6 +11,7 @@
 #include <consensus/merkle.h>
 #include <interfaces/chain.h>
 #include <kernel/chain.h>
+#include <kernel/types.h>
 #include <node/blockstorage.h>
 #include <outputtype.h>
 #include <policy/feerate.h>
@@ -39,6 +40,7 @@
 #include <utility>
 #include <vector>
 
+using kernel::ChainstateRole;
 using wallet::CWallet;
 using wallet::CreateMockableWalletDatabase;
 using wallet::WALLET_FLAG_DESCRIPTORS;
@@ -101,7 +103,7 @@ void generateFakeBlock(const CChainParams& params,
 
     // notify wallet
     const auto& pindex = WITH_LOCK(::cs_main, return context.chainman->ActiveChain().Tip());
-    wallet.blockConnected(ChainstateRole::NORMAL, kernel::MakeBlockInfo(pindex, &block));
+    wallet.blockConnected(ChainstateRole{}, kernel::MakeBlockInfo(pindex, &block));
 }
 
 struct PreSelectInputs {
diff --git a/src/bench/wallet_migration.cpp b/src/bench/wallet_migration.cpp
index 0ce23a49..9d61b984 100644
--- a/src/bench/wallet_migration.cpp
+++ b/src/bench/wallet_migration.cpp
@@ -6,6 +6,7 @@
 #include <interfaces/chain.h>
 #include <interfaces/wallet.h>
 #include <kernel/chain.h>
+#include <kernel/types.h>
 #include <node/context.h>
 #include <test/util/mining.h>
 #include <test/util/setup_common.h>
diff --git a/src/index/base.cpp b/src/index/base.cpp
index a94b4ca7..425f9f7e 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -10,6 +10,7 @@
 #include <interfaces/chain.h>
 #include <interfaces/types.h>
 #include <kernel/chain.h>
+#include <kernel/types.h>
 #include <logging.h>
 #include <node/abort.h>
 #include <node/blockstorage.h>
@@ -42,6 +43,8 @@
 #include <utility>
 #include <vector>
 
+using kernel::ChainstateRole;
+
 constexpr uint8_t DB_BEST_BLOCK{'B'};
 
 constexpr auto SYNC_LOG_INTERVAL{30s};
@@ -323,15 +326,13 @@ bool BaseIndex::Rewind(const CBlockIndex* current_tip, const CBlockIndex* new_ti
     return true;
 }
 
-void BaseIndex::BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex)
+void BaseIndex::BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex)
 {
-    // Ignore events from the assumed-valid chain; we will process its blocks
-    // (sequentially) after it is fully verified by the background chainstate. This
-    // is to avoid any out-of-order indexing.
+    // Ignore events from not fully validated chains to avoid out-of-order indexing.
     //
     // TODO at some point we could parameterize whether a particular index can be
     // built out of order, but for now just do the conservative simple thing.
-    if (role == ChainstateRole::ASSUMEDVALID) {
+    if (!role.validated) {
         return;
     }
 
@@ -377,11 +378,10 @@ void BaseIndex::BlockConnected(ChainstateRole role, const std::shared_ptr<const
     }
 }
 
-void BaseIndex::ChainStateFlushed(ChainstateRole role, const CBlockLocator& locator)
+void BaseIndex::ChainStateFlushed(const ChainstateRole& role, const CBlockLocator& locator)
 {
-    // Ignore events from the assumed-valid chain; we will process its blocks
-    // (sequentially) after it is fully verified by the background chainstate.
-    if (role == ChainstateRole::ASSUMEDVALID) {
+    // Ignore events from not fully validated chains to avoid out-of-order indexing.
+    if (!role.validated) {
         return;
     }
 
diff --git a/src/index/base.h b/src/index/base.h
index cbd0211a..8cb8ad8e 100644
--- a/src/index/base.h
+++ b/src/index/base.h
@@ -118,9 +118,9 @@ protected:
     Chainstate* m_chainstate{nullptr};
     const std::string m_name;
 
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override;
+    void BlockConnected(const kernel::ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override;
 
-    void ChainStateFlushed(ChainstateRole role, const CBlockLocator& locator) override;
+    void ChainStateFlushed(const kernel::ChainstateRole& role, const CBlockLocator& locator) override;
 
     /// Return custom notification options for index.
     [[nodiscard]] virtual interfaces::Chain::NotifyOptions CustomOptions() { return {}; }
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 40291d20..17417218 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -30,10 +30,12 @@ class Coin;
 class uint256;
 enum class MemPoolRemovalReason;
 enum class RBFTransactionState;
-enum class ChainstateRole;
 struct bilingual_str;
 struct CBlockLocator;
 struct FeeCalculation;
+namespace kernel {
+struct ChainstateRole;
+} // namespace kernel
 namespace node {
 struct NodeContext;
 } // namespace node
@@ -321,10 +323,10 @@ public:
         virtual ~Notifications() = default;
         virtual void transactionAddedToMempool(const CTransactionRef& tx) {}
         virtual void transactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRemovalReason reason) {}
-        virtual void blockConnected(ChainstateRole role, const BlockInfo& block) {}
+        virtual void blockConnected(const kernel::ChainstateRole& role, const BlockInfo& block) {}
         virtual void blockDisconnected(const BlockInfo& block) {}
         virtual void updatedBlockTip() {}
-        virtual void chainStateFlushed(ChainstateRole role, const CBlockLocator& locator) {}
+        virtual void chainStateFlushed(const kernel::ChainstateRole& role, const CBlockLocator& locator) {}
     };
 
     //! Options specifying which chain notifications are required.
diff --git a/src/kernel/bitcoinkernel.cpp b/src/kernel/bitcoinkernel.cpp
index be7c22de..3a36e2c8 100644
--- a/src/kernel/bitcoinkernel.cpp
+++ b/src/kernel/bitcoinkernel.cpp
@@ -51,6 +51,7 @@
 #include <utility>
 #include <vector>
 
+using kernel::ChainstateRole;
 using util::ImmediateTaskRunner;
 
 // Define G_TRANSLATION_FUN symbol in libbitcoinkernel library so users of the
@@ -359,7 +360,7 @@ protected:
         }
     }
 
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
+    void BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
     {
         if (m_cbs.block_connected) {
             m_cbs.block_connected(m_cbs.user_data,
diff --git a/src/kernel/chain.cpp b/src/kernel/chain.cpp
index 318c956b..52da2e3c 100644
--- a/src/kernel/chain.cpp
+++ b/src/kernel/chain.cpp
@@ -5,11 +5,14 @@
 #include <chain.h>
 #include <interfaces/chain.h>
 #include <kernel/chain.h>
+#include <kernel/types.h>
 #include <sync.h>
 #include <uint256.h>
 
 class CBlock;
 
+using kernel::ChainstateRole;
+
 namespace kernel {
 interfaces::BlockInfo MakeBlockInfo(const CBlockIndex* index, const CBlock* data)
 {
@@ -25,14 +28,15 @@ interfaces::BlockInfo MakeBlockInfo(const CBlockIndex* index, const CBlock* data
     info.data = data;
     return info;
 }
-} // namespace kernel
 
 std::ostream& operator<<(std::ostream& os, const ChainstateRole& role) {
-    switch(role) {
-        case ChainstateRole::NORMAL: os << "normal"; break;
-        case ChainstateRole::ASSUMEDVALID: os << "assumedvalid"; break;
-        case ChainstateRole::BACKGROUND: os << "background"; break;
-        default: os.setstate(std::ios_base::failbit);
+    if (!role.validated) {
+        os << "assumedvalid";
+    } else if (role.historical) {
+        os << "background";
+    } else {
+        os << "normal";
     }
     return os;
 }
+} // namespace kernel
diff --git a/src/kernel/chain.h b/src/kernel/chain.h
index feba24a5..7dbd0eb6 100644
--- a/src/kernel/chain.h
+++ b/src/kernel/chain.h
@@ -14,26 +14,10 @@ struct BlockInfo;
 } // namespace interfaces
 
 namespace kernel {
+struct ChainstateRole;
 //! Return data from block index.
 interfaces::BlockInfo MakeBlockInfo(const CBlockIndex* block_index, const CBlock* data = nullptr);
-
-} // namespace kernel
-
-//! This enum describes the various roles a specific Chainstate instance can take.
-//! Other parts of the system sometimes need to vary in behavior depending on the
-//! existence of a background validation chainstate, e.g. when building indexes.
-enum class ChainstateRole {
-    // Single chainstate in use, "normal" IBD mode.
-    NORMAL,
-
-    // Doing IBD-style validation in the background. Implies use of an assumed-valid
-    // chainstate.
-    BACKGROUND,
-
-    // Active assumed-valid chainstate. Implies use of a background IBD chainstate.
-    ASSUMEDVALID,
-};
-
 std::ostream& operator<<(std::ostream& os, const ChainstateRole& role);
+} // namespace kernel
 
 #endif // BITCOIN_KERNEL_CHAIN_H
diff --git a/src/kernel/types.h b/src/kernel/types.h
new file mode 100644
index 00000000..164d4cfd
--- /dev/null
+++ b/src/kernel/types.h
@@ -0,0 +1,30 @@
+// Copyright (c) The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+//! @file kernel/types.h is a home for simple enum and struct type definitions
+//! that can be used internally by functions in the libbitcoin_kernel library,
+//! but also used externally by node, wallet, and GUI code.
+//!
+//! This file is intended to define only simple types that do not have external
+//! dependencies. More complicated types should be defined in dedicated header
+//! files.
+
+#ifndef BITCOIN_KERNEL_TYPES_H
+#define BITCOIN_KERNEL_TYPES_H
+
+namespace kernel {
+//! Information about chainstate that notifications are sent from.
+struct ChainstateRole {
+    //! Whether this is a notification from a chainstate that's been fully
+    //! validated starting from the genesis block. False if it is from an
+    //! assumeutxo snapshot chainstate that has not been validated yet.
+    bool validated{true};
+
+    //! Whether this is a historical chainstate downloading old blocks to
+    //! validate an assumeutxo snapshot, not syncing to the network tip.
+    bool historical{false};
+};
+} // namespace kernel
+
+#endif // BITCOIN_KERNEL_TYPES_H
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 09b2f221..d7fd2879 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -22,7 +22,7 @@
 #include <flatfile.h>
 #include <headerssync.h>
 #include <index/blockfilterindex.h>
-#include <kernel/chain.h>
+#include <kernel/types.h>
 #include <logging.h>
 #include <merkleblock.h>
 #include <net.h>
@@ -85,6 +85,7 @@
 #include <typeinfo>
 #include <utility>
 
+using kernel::ChainstateRole;
 using namespace util::hex_literals;
 
 TRACEPOINT_SEMAPHORE(net, inbound_message);
@@ -507,7 +508,7 @@ public:
     /** Overridden from CValidationInterface. */
     void ActiveTipChange(const CBlockIndex& new_tip, bool) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override
+    void BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
     void BlockDisconnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex* pindex) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_tx_download_mutex);
@@ -1946,7 +1947,7 @@ void PeerManagerImpl::ActiveTipChange(const CBlockIndex& new_tip, bool is_ibd)
  * possibly reduce dynamic block stalling timeout.
  */
 void PeerManagerImpl::BlockConnected(
-    ChainstateRole role,
+    const ChainstateRole& role,
     const std::shared_ptr<const CBlock>& pblock,
     const CBlockIndex* pindex)
 {
@@ -1965,8 +1966,8 @@ void PeerManagerImpl::BlockConnected(
     }
 
     // The following task can be skipped since we don't maintain a mempool for
-    // the ibd/background chainstate.
-    if (role == ChainstateRole::BACKGROUND) {
+    // the historical chainstate.
+    if (role.historical) {
         return;
     }
     LOCK(m_tx_download_mutex);
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index a5984df6..c5d26e5c 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -12,9 +12,11 @@
 #include <flatfile.h>
 #include <hash.h>
 #include <kernel/blockmanager_opts.h>
+#include <kernel/chain.h>
 #include <kernel/chainparams.h>
 #include <kernel/messagestartchars.h>
 #include <kernel/notifications_interface.h>
+#include <kernel/types.h>
 #include <logging.h>
 #include <pow.h>
 #include <primitives/block.h>
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index ac817e01..dfcf6629 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -81,6 +81,7 @@ using interfaces::MakeSignalHandler;
 using interfaces::Mining;
 using interfaces::Node;
 using interfaces::WalletLoader;
+using kernel::ChainstateRole;
 using node::BlockAssembler;
 using node::BlockWaitOptions;
 using util::Join;
@@ -461,7 +462,7 @@ public:
     {
         m_notifications->transactionRemovedFromMempool(tx, reason);
     }
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* index) override
+    void BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* index) override
     {
         m_notifications->blockConnected(role, kernel::MakeBlockInfo(index, block.get()));
     }
@@ -473,7 +474,8 @@ public:
     {
         m_notifications->updatedBlockTip();
     }
-    void ChainStateFlushed(ChainstateRole role, const CBlockLocator& locator) override {
+    void ChainStateFlushed(const ChainstateRole& role, const CBlockLocator& locator) override
+    {
         m_notifications->chainStateFlushed(role, locator);
     }
     std::shared_ptr<Chain::Notifications> m_notifications;
diff --git a/src/test/chainstate_write_tests.cpp b/src/test/chainstate_write_tests.cpp
index e1b82ebc..5c459227 100644
--- a/src/test/chainstate_write_tests.cpp
+++ b/src/test/chainstate_write_tests.cpp
@@ -8,6 +8,8 @@
 
 #include <boost/test/unit_test.hpp>
 
+using kernel::ChainstateRole;
+
 // Taken from validation.cpp
 static constexpr auto DATABASE_WRITE_INTERVAL_MIN{50min};
 static constexpr auto DATABASE_WRITE_INTERVAL_MAX{70min};
@@ -18,7 +20,7 @@ BOOST_FIXTURE_TEST_CASE(chainstate_write_interval, TestingSetup)
 {
     struct TestSubscriber final : CValidationInterface {
         bool m_did_flush{false};
-        void ChainStateFlushed(ChainstateRole, const CBlockLocator&) override
+        void ChainStateFlushed(const ChainstateRole&, const CBlockLocator&) override
         {
             m_did_flush = true;
         }
@@ -55,7 +57,7 @@ BOOST_FIXTURE_TEST_CASE(write_during_multiblock_activation, TestChain100Setup)
     {
         const CBlockIndex* m_tip{nullptr};
         const CBlockIndex* m_flushed_at_block{nullptr};
-        void ChainStateFlushed(ChainstateRole, const CBlockLocator&) override
+        void ChainStateFlushed(const ChainstateRole&, const CBlockLocator&) override
         {
             m_flushed_at_block = m_tip;
         }
diff --git a/src/test/coinstatsindex_tests.cpp b/src/test/coinstatsindex_tests.cpp
index 7d54f0fd..d55fb1b0 100644
--- a/src/test/coinstatsindex_tests.cpp
+++ b/src/test/coinstatsindex_tests.cpp
@@ -6,12 +6,15 @@
 #include <index/coinstatsindex.h>
 #include <interfaces/chain.h>
 #include <kernel/coinstats.h>
+#include <kernel/types.h>
 #include <test/util/setup_common.h>
 #include <test/util/validation.h>
 #include <validation.h>
 
 #include <boost/test/unit_test.hpp>
 
+using kernel::ChainstateRole;
+
 BOOST_AUTO_TEST_SUITE(coinstatsindex_tests)
 
 BOOST_FIXTURE_TEST_CASE(coinstatsindex_initial_sync, TestChain100Setup)
@@ -101,7 +104,7 @@ BOOST_FIXTURE_TEST_CASE(coinstatsindex_unclean_shutdown, TestChain100Setup)
         // Send block connected notification, then stop the index without
         // sending a chainstate flushed notification. Prior to #24138, this
         // would cause the index to be corrupted and fail to reload.
-        ValidationInterfaceTest::BlockConnected(ChainstateRole::NORMAL, index, new_block, new_block_index);
+        ValidationInterfaceTest::BlockConnected(ChainstateRole{}, index, new_block, new_block_index);
         index.Stop();
     }
 
diff --git a/src/test/util/validation.cpp b/src/test/util/validation.cpp
index ce558078..ae8642f9 100644
--- a/src/test/util/validation.cpp
+++ b/src/test/util/validation.cpp
@@ -9,6 +9,8 @@
 #include <validation.h>
 #include <validationinterface.h>
 
+using kernel::ChainstateRole;
+
 void TestChainstateManager::DisableNextWrite()
 {
     struct TestChainstate : public Chainstate {
@@ -18,6 +20,7 @@ void TestChainstateManager::DisableNextWrite()
         static_cast<TestChainstate*>(cs)->ResetNextWrite();
     }
 }
+
 void TestChainstateManager::ResetIbd()
 {
     m_cached_finished_ibd = false;
@@ -32,10 +35,10 @@ void TestChainstateManager::JumpOutOfIbd()
 }
 
 void ValidationInterfaceTest::BlockConnected(
-        ChainstateRole role,
-        CValidationInterface& obj,
-        const std::shared_ptr<const CBlock>& block,
-        const CBlockIndex* pindex)
+    const ChainstateRole& role,
+    CValidationInterface& obj,
+    const std::shared_ptr<const CBlock>& block,
+    const CBlockIndex* pindex)
 {
     obj.BlockConnected(role, block, pindex);
 }
diff --git a/src/test/util/validation.h b/src/test/util/validation.h
index f9c6a8ac..4a24c97e 100644
--- a/src/test/util/validation.h
+++ b/src/test/util/validation.h
@@ -22,7 +22,7 @@ class ValidationInterfaceTest
 {
 public:
     static void BlockConnected(
-        ChainstateRole role,
+        const kernel::ChainstateRole& role,
         CValidationInterface& obj,
         const std::shared_ptr<const CBlock>& block,
         const CBlockIndex* pindex);
diff --git a/src/test/validation_block_tests.cpp b/src/test/validation_block_tests.cpp
index a0b23f5d..9f574be8 100644
--- a/src/test/validation_block_tests.cpp
+++ b/src/test/validation_block_tests.cpp
@@ -19,6 +19,7 @@
 
 #include <thread>
 
+using kernel::ChainstateRole;
 using node::BlockAssembler;
 
 namespace validation_block_tests {
@@ -43,7 +44,7 @@ struct TestSubscriber final : public CValidationInterface {
         BOOST_CHECK_EQUAL(m_expected_tip, pindexNew->GetBlockHash());
     }
 
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
+    void BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) override
     {
         BOOST_CHECK_EQUAL(m_expected_tip, block->hashPrevBlock);
         BOOST_CHECK_EQUAL(m_expected_tip, pindex->pprev->GetBlockHash());
diff --git a/src/test/validationinterface_tests.cpp b/src/test/validationinterface_tests.cpp
index 8a24b282..0b0bae80 100644
--- a/src/test/validationinterface_tests.cpp
+++ b/src/test/validationinterface_tests.cpp
@@ -8,7 +8,6 @@
 #include <scheduler.h>
 #include <test/util/setup_common.h>
 #include <util/check.h>
-#include <kernel/chain.h>
 #include <validationinterface.h>
 
 #include <atomic>
diff --git a/src/validation.cpp b/src/validation.cpp
index da60efbc..c229851e 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -20,13 +20,13 @@
 #include <cuckoocache.h>
 #include <flatfile.h>
 #include <hash.h>
-#include <kernel/chain.h>
 #include <kernel/chainparams.h>
 #include <kernel/coinstats.h>
 #include <kernel/disconnected_transactions.h>
 #include <kernel/mempool_entry.h>
 #include <kernel/messagestartchars.h>
 #include <kernel/notifications_interface.h>
+#include <kernel/types.h>
 #include <kernel/warning.h>
 #include <logging.h>
 #include <logging/timer.h>
@@ -77,6 +77,7 @@
 #include <utility>
 
 using kernel::CCoinsStats;
+using kernel::ChainstateRole;
 using kernel::CoinStatsHashType;
 using kernel::ComputeUTXOStats;
 using kernel::Notifications;
@@ -1986,7 +1987,7 @@ void Chainstate::CheckForkWarningConditions()
 {
     AssertLockHeld(cs_main);
 
-    if (this->GetRole() == ChainstateRole::BACKGROUND) {
+    if (this->GetRole().historical) {
         return;
     }
 
@@ -2532,7 +2533,8 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
              Ticks<MillisecondsDouble>(m_chainman.time_forks) / m_chainman.num_blocks_total);
 
     const bool fScriptChecks{!!script_check_reason};
-    if (script_check_reason != m_last_script_check_reason_logged && GetRole() == ChainstateRole::NORMAL) {
+    const kernel::ChainstateRole role{GetRole()};
+    if (script_check_reason != m_last_script_check_reason_logged && role.validated && !role.historical) {
         if (fScriptChecks) {
             LogInfo("Enabling script verification at block #%d (%s): %s.",
                     pindex->nHeight, block_hash.ToString(), script_check_reason);
@@ -4656,7 +4658,7 @@ bool Chainstate::LoadChainTip()
               m_chainman.GuessVerificationProgress(tip));
 
     // Ensure KernelNotifications m_tip_block is set even if no new block arrives.
-    if (this->GetRole() != ChainstateRole::BACKGROUND) {
+    if (!this->GetRole().historical) {
         // Ignoring return value for now.
         (void)m_chainman.GetNotifications().blockTip(
             /*state=*/GetSynchronizationState(/*init=*/true, m_chainman.m_blockman.m_blockfiles_indexed),
@@ -6354,7 +6356,7 @@ bool ChainstateManager::DeleteSnapshotChainstate()
 
 ChainstateRole Chainstate::GetRole() const
 {
-    return m_target_blockhash ? ChainstateRole::BACKGROUND : m_assumeutxo == Assumeutxo::UNVALIDATED ? ChainstateRole::ASSUMEDVALID : ChainstateRole::NORMAL;
+    return ChainstateRole{.validated = m_assumeutxo == Assumeutxo::VALIDATED, .historical = bool{m_target_blockhash}};
 }
 
 void ChainstateManager::RecalculateBestHeader()
diff --git a/src/validation.h b/src/validation.h
index 464dcbd0..0f7fa2cb 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -58,6 +58,9 @@ class DisconnectedBlockTransactions;
 struct PrecomputedTransactionData;
 struct LockPoints;
 struct AssumeutxoData;
+namespace kernel {
+struct ChainstateRole;
+} // namespace kernel
 namespace node {
 class SnapshotMetadata;
 } // namespace node
@@ -586,7 +589,7 @@ public:
     //! documentation for a description of the different types of chainstates.
     //!
     //! @sa ChainstateRole
-    ChainstateRole GetRole() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
+    kernel::ChainstateRole GetRole() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * Initialize the CoinsViews UTXO set database management data structures. The in-memory
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index 313f730e..c4cd1010 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -7,9 +7,9 @@
 
 #include <chain.h>
 #include <consensus/validation.h>
-#include <kernel/chain.h>
 #include <kernel/mempool_entry.h>
 #include <kernel/mempool_removal_reason.h>
+#include <kernel/types.h>
 #include <logging.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
@@ -21,6 +21,8 @@
 #include <unordered_map>
 #include <utility>
 
+using kernel::ChainstateRole;
+
 /**
  * ValidationSignalsImpl manages a list of shared_ptr<CValidationInterface> callbacks.
  *
@@ -209,7 +211,8 @@ void ValidationSignals::TransactionRemovedFromMempool(const CTransactionRef& tx,
                           RemovalReasonToString(reason));
 }
 
-void ValidationSignals::BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex) {
+void ValidationSignals::BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
+{
     auto event = [role, pblock, pindex, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.BlockConnected(role, pblock, pindex); });
     };
@@ -238,7 +241,8 @@ void ValidationSignals::BlockDisconnected(const std::shared_ptr<const CBlock>& p
                           pindex->nHeight);
 }
 
-void ValidationSignals::ChainStateFlushed(ChainstateRole role, const CBlockLocator &locator) {
+void ValidationSignals::ChainStateFlushed(const ChainstateRole& role, const CBlockLocator& locator)
+{
     auto event = [role, locator, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.ChainStateFlushed(role, locator); });
     };
diff --git a/src/validationinterface.h b/src/validationinterface.h
index e0a88ad0..4777e8dc 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -6,7 +6,6 @@
 #ifndef BITCOIN_VALIDATIONINTERFACE_H
 #define BITCOIN_VALIDATIONINTERFACE_H
 
-#include <kernel/chain.h>
 #include <kernel/cs_main.h>
 #include <primitives/transaction.h>
 #include <sync.h>
@@ -17,6 +16,9 @@
 #include <memory>
 #include <vector>
 
+namespace kernel {
+struct ChainstateRole;
+} // namespace kernel
 namespace util {
 class TaskRunnerInterface;
 } // namespace util
@@ -118,7 +120,7 @@ protected:
      *
      * Called on a background thread.
      */
-    virtual void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock> &block, const CBlockIndex *pindex) {}
+    virtual void BlockConnected(const kernel::ChainstateRole& role, const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex) {}
     /**
      * Notifies listeners of a block being disconnected
      * Provides the block that was disconnected.
@@ -143,7 +145,7 @@ protected:
      *
      * Called on a background thread.
      */
-    virtual void ChainStateFlushed(ChainstateRole role, const CBlockLocator &locator) {}
+    virtual void ChainStateFlushed(const kernel::ChainstateRole& role, const CBlockLocator& locator) {}
     /**
      * Notifies listeners of a block validation result.
      * If the provided BlockValidationState IsValid, the provided block
@@ -221,9 +223,9 @@ public:
     void TransactionAddedToMempool(const NewMempoolTransactionInfo&, uint64_t mempool_sequence);
     void TransactionRemovedFromMempool(const CTransactionRef&, MemPoolRemovalReason, uint64_t mempool_sequence);
     void MempoolTransactionsRemovedForBlock(const std::vector<RemovedMempoolTransactionInfo>&, unsigned int nBlockHeight);
-    void BlockConnected(ChainstateRole, const std::shared_ptr<const CBlock> &, const CBlockIndex *pindex);
+    void BlockConnected(const kernel::ChainstateRole&, const std::shared_ptr<const CBlock>&, const CBlockIndex* pindex);
     void BlockDisconnected(const std::shared_ptr<const CBlock> &, const CBlockIndex* pindex);
-    void ChainStateFlushed(ChainstateRole, const CBlockLocator &);
+    void ChainStateFlushed(const kernel::ChainstateRole&, const CBlockLocator&);
     void BlockChecked(const std::shared_ptr<const CBlock>&, const BlockValidationState&);
     void NewPoWValidBlock(const CBlockIndex *, const std::shared_ptr<const CBlock>&);
 };
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 86474a45..d7b749bc 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -22,8 +22,8 @@
 #include <interfaces/chain.h>
 #include <interfaces/handler.h>
 #include <interfaces/wallet.h>
-#include <kernel/chain.h>
 #include <kernel/mempool_removal_reason.h>
+#include <kernel/types.h>
 #include <key.h>
 #include <key_io.h>
 #include <logging.h>
@@ -87,6 +87,7 @@ using common::AmountErrMsg;
 using common::AmountHighWarn;
 using common::PSBTError;
 using interfaces::FoundBlock;
+using kernel::ChainstateRole;
 using util::ReplaceAll;
 using util::ToString;
 
@@ -1477,9 +1478,9 @@ void CWallet::transactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRe
     }
 }
 
-void CWallet::blockConnected(ChainstateRole role, const interfaces::BlockInfo& block)
+void CWallet::blockConnected(const ChainstateRole& role, const interfaces::BlockInfo& block)
 {
-    if (role == ChainstateRole::BACKGROUND) {
+    if (role.historical) {
         return;
     }
     assert(block.data);
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 275d4ead..1d463564 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -629,7 +629,7 @@ public:
     CWalletTx* AddToWallet(CTransactionRef tx, const TxState& state, const UpdateWalletTxFn& update_wtx=nullptr, bool rescanning_old_block = false);
     bool LoadToWallet(const Txid& hash, const UpdateWalletTxFn& fill_wtx) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void transactionAddedToMempool(const CTransactionRef& tx) override;
-    void blockConnected(ChainstateRole role, const interfaces::BlockInfo& block) override;
+    void blockConnected(const kernel::ChainstateRole& role, const interfaces::BlockInfo& block) override;
     void blockDisconnected(const interfaces::BlockInfo& block) override;
     void updatedBlockTip() override;
     int64_t RescanFromTime(int64_t startTime, const WalletRescanReserver& reserver, bool update);
diff --git a/src/zmq/zmqnotificationinterface.cpp b/src/zmq/zmqnotificationinterface.cpp
index e5b5f9d8..316c7a19 100644
--- a/src/zmq/zmqnotificationinterface.cpp
+++ b/src/zmq/zmqnotificationinterface.cpp
@@ -5,8 +5,8 @@
 #include <zmq/zmqnotificationinterface.h>
 
 #include <common/args.h>
-#include <kernel/chain.h>
 #include <kernel/mempool_entry.h>
+#include <kernel/types.h>
 #include <logging.h>
 #include <netbase.h>
 #include <primitives/block.h>
@@ -24,6 +24,8 @@
 #include <utility>
 #include <vector>
 
+using kernel::ChainstateRole;
+
 CZMQNotificationInterface::CZMQNotificationInterface() = default;
 
 CZMQNotificationInterface::~CZMQNotificationInterface()
@@ -176,9 +178,9 @@ void CZMQNotificationInterface::TransactionRemovedFromMempool(const CTransaction
     });
 }
 
-void CZMQNotificationInterface::BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected)
+void CZMQNotificationInterface::BlockConnected(const ChainstateRole& role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected)
 {
-    if (role == ChainstateRole::BACKGROUND) {
+    if (role.historical) {
         return;
     }
     for (const CTransactionRef& ptx : pblock->vtx) {
diff --git a/src/zmq/zmqnotificationinterface.h b/src/zmq/zmqnotificationinterface.h
index 5dacf3b3..12d805c1 100644
--- a/src/zmq/zmqnotificationinterface.h
+++ b/src/zmq/zmqnotificationinterface.h
@@ -35,7 +35,7 @@ protected:
     // CValidationInterface
     void TransactionAddedToMempool(const NewMempoolTransactionInfo& tx, uint64_t mempool_sequence) override;
     void TransactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRemovalReason reason, uint64_t mempool_sequence) override;
-    void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override;
+    void BlockConnected(const kernel::ChainstateRole& role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override;
     void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexDisconnected) override;
     void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override;