miden_client/test_utils/

mock.rs

use alloc::boxed::Box;
use alloc::collections::{BTreeMap, BTreeSet};
use alloc::string::String;
use alloc::sync::Arc;
use alloc::vec::Vec;
use core::sync::atomic::{AtomicBool, AtomicUsize, Ordering};

use miden_protocol::Word;
use miden_protocol::account::{
    AccountId,
    AccountUpdateDetails,
    AccountVaultPatch,
    StorageMapKey,
    StorageMapPatchEntries,
    StorageSlot,
    StorageSlotContent,
    StorageSlotName,
    StorageSlotType,
};
use miden_protocol::address::NetworkId;
use miden_protocol::batch::{ProposedBatch, ProvenBatch};
use miden_protocol::block::{BlockHeader, BlockNumber, SignedBlock};
use miden_protocol::crypto::merkle::MerklePath;
use miden_protocol::crypto::merkle::mmr::{Forest, Mmr, MmrProof};
use miden_protocol::crypto::merkle::smt::PartialSmt;
use miden_protocol::note::{NoteAttachments, NoteHeader, NoteId, NoteScript, NoteTag};
use miden_protocol::protocol_config::ProtocolConfig;
use miden_protocol::transaction::{ExecutedTransaction, OutputNote, ProvenTransaction};
use miden_protocol::vm::ExecutionProof;
use miden_testing::{MockChain, MockChainNote};
use miden_tx::utils::sync::RwLock;

use crate::Client;
use crate::rpc::domain::account::{
    AccountDetails,
    AccountProof,
    AccountStorageDetails,
    AccountStorageMapDetails,
    AccountVaultDetails,
    GetAccountRequest,
    StorageMapEntries,
    StorageMapEntry,
    StorageMapFetch,
    VaultFetch,
};
use crate::rpc::domain::account_vault::AccountVaultInfo;
use crate::rpc::domain::note::{CommittedNote, FetchedNote, SyncNotesBlock};
use crate::rpc::domain::nullifier::NullifierUpdate;
use crate::rpc::domain::status::NetworkNoteStatusInfo;
use crate::rpc::domain::storage_map::StorageMapInfo;
use crate::rpc::domain::sync::{ChainMmrInfo, SyncTarget};
use crate::rpc::domain::transaction::TransactionRecord;
use crate::rpc::encryption::{AttestedTransactionEncryptionKey, SealedTransactionInputs};
use crate::rpc::{AccountStateAt, NodeRpcClient, RpcEndpoint, RpcError, RpcStatusInfo};

pub type MockClient<AUTH> = Client<AUTH>;

#[derive(Clone, Copy)]
struct BlockHeaderRequest {
    block_num: Option<BlockNumber>,
    include_mmr_proof: bool,
}

/// Mock RPC API
///
/// This struct implements the RPC API used by the client to communicate with the node. It simulates
/// most of the functionality of the actual node, with some small differences:
/// - It uses a [`MockChain`] to simulate the blockchain state.
/// - Blocks are not automatically created after time passes, but rather new blocks are created when
///   calling the `prove_block` method.
/// - Network account and transactions aren't supported in the current version.
/// - Account update block numbers aren't tracked, so any endpoint that returns when certain account
///   updates were made will return the chain tip block number instead.
#[derive(Clone)]
pub struct MockRpcApi {
    account_commitment_updates: Arc<RwLock<BTreeMap<BlockNumber, BTreeMap<AccountId, Word>>>>,
    pub mock_chain: Arc<RwLock<MockChain>>,
    /// Chain snapshots used to answer block-pinned account queries.
    historical_chains: Arc<RwLock<BTreeMap<BlockNumber, Arc<MockChain>>>>,
    oversize_threshold: usize,
    /// Note headers to report as erased in sync transaction responses.
    erased_notes: Arc<RwLock<Vec<NoteHeader>>>,
    /// Attachment content `get_notes_by_id` serves for private notes, populated by
    /// `submit_proven_transaction` and by `register_private_note_attachments`. A note absent here
    /// is served with empty attachments, which is how a test simulates a withholding node.
    private_note_attachments: Arc<RwLock<BTreeMap<NoteId, NoteAttachments>>>,
    /// Test overrides for the MMR paths returned by `sync_notes`, keyed by block number.
    sync_notes_mmr_path_overrides: Arc<RwLock<BTreeMap<BlockNumber, MerklePath>>>,
    /// Number of `get_notes_by_id` requests served, so a test can assert that a flow avoided the
    /// round trip.
    get_notes_by_id_calls: Arc<AtomicUsize>,
    /// Block header requests, recorded with the requested block and proof flag.
    block_header_requests: Arc<RwLock<Vec<BlockHeaderRequest>>>,
    /// Number of `get_account` requests served, so a test can assert that a flow avoided the round
    /// trip.
    get_account_calls: Arc<AtomicUsize>,
    /// Failures to serve instead of answering, keyed by [`RpcEndpoint::proto_name`] and set by
    /// [`MockRpcApi::fail_next_call`]. An entry is removed when served, so the call after it
    /// answers normally and a test can exercise a retry.
    next_call_failures: Arc<RwLock<BTreeMap<&'static str, RpcError>>>,
    /// Invitation code each account was registered with, recorded by `register_account`.
    registered_accounts: Arc<RwLock<BTreeMap<AccountId, String>>>,
    /// Whether `is_account_allowed` consults `registered_accounts`. A node that does not enforce
    /// the allowlist answers `true` for every account, which is the default here so that tests
    /// which deploy accounts need no registration.
    allowlist_enforced: Arc<AtomicBool>,
    /// Number of `is_account_allowed` requests served, so a test can assert that a flow avoided the
    /// round trip.
    is_account_allowed_calls: Arc<AtomicUsize>,
    /// Sealed inputs handed to `submit_proven_batch`, one entry per call and recorded before any
    /// staged failure is served, so a test can assert that a resubmission sealed again instead of
    /// reusing a cached ciphertext.
    submitted_batch_sealed_inputs: Arc<RwLock<Vec<Vec<SealedTransactionInputs>>>>,
}

impl Default for MockRpcApi {
    fn default() -> Self {
        Self::new(MockChain::new())
    }
}

impl MockRpcApi {
    // Constant to use in mocked pagination.
    const PAGINATION_BLOCK_LIMIT: u32 = 5;

    /// Creates a new [`MockRpcApi`] instance with the state of the provided [`MockChain`].
    pub fn new(mock_chain: MockChain) -> Self {
        Self {
            account_commitment_updates: Arc::new(RwLock::new(build_account_updates(&mock_chain))),
            mock_chain: Arc::new(RwLock::new(mock_chain)),
            historical_chains: Arc::new(RwLock::new(BTreeMap::new())),
            oversize_threshold: 1000,
            erased_notes: Arc::new(RwLock::new(Vec::new())),
            private_note_attachments: Arc::new(RwLock::new(BTreeMap::new())),
            sync_notes_mmr_path_overrides: Arc::new(RwLock::new(BTreeMap::new())),
            get_notes_by_id_calls: Arc::new(AtomicUsize::new(0)),
            block_header_requests: Arc::new(RwLock::new(Vec::new())),
            get_account_calls: Arc::new(AtomicUsize::new(0)),
            next_call_failures: Arc::new(RwLock::new(BTreeMap::new())),
            registered_accounts: Arc::new(RwLock::new(BTreeMap::new())),
            allowlist_enforced: Arc::new(AtomicBool::new(false)),
            is_account_allowed_calls: Arc::new(AtomicUsize::new(0)),
            submitted_batch_sealed_inputs: Arc::new(RwLock::new(Vec::new())),
        }
    }

    /// Makes `is_account_allowed` answer from the recorded registrations, modelling a node that
    /// enforces the account allowlist. Without this the mock answers `true` for every account.
    pub fn enforce_account_allowlist(&self) {
        self.allowlist_enforced.store(true, Ordering::SeqCst);
    }

    /// Id of the first account updated in the mock chain's proven blocks, in block then
    /// within-block order. Tests use it to get hold of an account the chain already knows.
    ///
    /// Panics if the chain has no account updates.
    pub fn first_account_id(&self) -> AccountId {
        self.mock_chain
            .read()
            .proven_blocks()
            .iter()
            .flat_map(|block| block.body().updated_accounts())
            .next()
            .expect("the mock chain must have at least one account update")
            .account_id()
    }

    /// Sealed inputs recorded by `submit_proven_batch`, one entry per call, including calls that
    /// went on to be served a staged failure. Within an entry the order matches the batch's
    /// transaction order.
    pub fn submitted_batch_sealed_inputs(&self) -> Vec<Vec<SealedTransactionInputs>> {
        self.submitted_batch_sealed_inputs.read().clone()
    }

    /// Makes the next call to `endpoint` fail with `error` instead of answering. The failure is
    /// consumed, so the call after it answers normally and a test can exercise a retry.
    ///
    /// Staging a failure for an endpoint whose mock implementation does not look for one is a
    /// silent no-op.
    pub fn fail_next_call(&self, endpoint: RpcEndpoint, error: RpcError) {
        self.next_call_failures.write().insert(endpoint.proto_name(), error);
    }

    /// Returns the failure staged for `endpoint`, removing it so it is served once.
    fn take_failure(&self, endpoint: RpcEndpoint) -> Option<RpcError> {
        self.next_call_failures.write().remove(endpoint.proto_name())
    }

    /// Returns the invitation code `account_id` was registered with, or `None` if this API served
    /// no registration for it.
    pub fn registered_invitation_code(&self, account_id: AccountId) -> Option<String> {
        self.registered_accounts.read().get(&account_id).cloned()
    }

    /// Registers the attachment content for a private note so that subsequent `get_notes_by_id`
    /// responses include it, mirroring a node that stores private-note attachments on-chain.
    pub fn register_private_note_attachments(&self, note_id: NoteId, attachments: NoteAttachments) {
        self.private_note_attachments.write().insert(note_id, attachments);
    }

    /// Returns how many `get_notes_by_id` requests this API has served.
    pub fn get_notes_by_id_call_count(&self) -> usize {
        self.get_notes_by_id_calls.load(Ordering::Relaxed)
    }

    /// Returns the proof flags of requests for `block_num`.
    pub fn block_header_requests(&self, block_num: BlockNumber) -> Vec<bool> {
        self.block_header_requests
            .read()
            .iter()
            .filter_map(|request| {
                (request.block_num == Some(block_num)).then_some(request.include_mmr_proof)
            })
            .collect()
    }

    /// Returns how many `get_account` requests this API has served.
    pub fn get_account_call_count(&self) -> usize {
        self.get_account_calls.load(Ordering::Relaxed)
    }

    /// Returns how many `is_account_allowed` requests this API has served.
    pub fn is_account_allowed_call_count(&self) -> usize {
        self.is_account_allowed_calls.load(Ordering::Relaxed)
    }

    /// Overrides the MMR path returned by `sync_notes` for the specified block.
    pub fn set_sync_notes_mmr_path(&self, block_num: BlockNumber, path: MerklePath) {
        self.sync_notes_mmr_path_overrides.write().insert(block_num, path);
    }

    /// Sets the oversize threshold for `get_account`. A storage map whose entries were requested in
    /// full comes back as `StorageMapEntries::LimitExceeded` past this threshold, and a vault with
    /// more assets than it comes back with the `too_many_assets` flag set.
    #[must_use]
    pub fn with_oversize_threshold(mut self, threshold: usize) -> Self {
        self.oversize_threshold = threshold;
        self
    }

    /// Registers a note header to be reported as erased in subsequent sync transaction responses.
    pub fn mark_note_as_erased(&self, header: NoteHeader) {
        self.erased_notes.write().push(header);
    }

    /// Returns the current MMR of the blockchain.
    pub fn get_mmr(&self) -> Mmr {
        self.mock_chain.read().blockchain().as_mmr().clone()
    }

    /// Returns the protocol configuration the mock chain commits to.
    pub fn protocol_config(&self) -> ProtocolConfig {
        self.mock_chain.read().protocol_config().clone()
    }

    /// Returns the chain tip block number.
    pub fn get_chain_tip_block_num(&self) -> BlockNumber {
        self.mock_chain.read().latest_block_header().block_num()
    }

    /// Adds an executed transaction to the pending transactions of the mock chain with a dummy
    /// proof. The next [`Self::prove_block`] call commits it.
    ///
    /// Tests use this method to put a transaction on chain without the cost of a real proof.
    pub fn add_pending_executed_transaction(&self, executed_transaction: &ExecutedTransaction) {
        self.mock_chain
            .write()
            .add_pending_executed_transaction(executed_transaction)
            .expect("mock chain should accept the executed transaction");
    }

    /// Advances the mock chain by proving the next block, committing all pending objects to the
    /// chain in the process.
    pub fn prove_block(&self) {
        let proven_block = {
            let mut mock_chain = self.mock_chain.write();
            let historical_block_num = mock_chain.latest_block_header().block_num();
            let snapshot = Arc::new(mock_chain.clone());
            let proven_block = mock_chain.prove_next_block().unwrap();
            self.historical_chains.write().insert(historical_block_num, snapshot);
            proven_block
        };
        let block_num = proven_block.header().block_num();
        let mut account_commitment_updates = self.account_commitment_updates.write();
        let updates: BTreeMap<AccountId, Word> = proven_block
            .body()
            .updated_accounts()
            .iter()
            .map(|update| (update.account_id(), update.final_state_commitment()))
            .collect();

        if !updates.is_empty() {
            account_commitment_updates.insert(block_num, updates);
        }
    }

    /// Removes the account-state snapshot for the specified block.
    ///
    /// Tests use this method to model a node that pruned historical account state.
    pub fn prune_account_state_at(&self, block_num: BlockNumber) {
        self.historical_chains.write().remove(&block_num);
    }

    /// Retrieves a block by its block number.
    fn get_block_by_num(&self, block_num: BlockNumber) -> BlockHeader {
        self.mock_chain.read().block_header(block_num.as_usize())
    }

    /// Retrieves account vault updates in a given block range. This method tries to simulate
    /// pagination by limiting the number of blocks processed per request.
    fn get_sync_account_vault_request(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_id: AccountId,
    ) -> (BlockNumber, BlockNumber, AccountVaultPatch) {
        let chain_tip = self.get_chain_tip_block_num();
        let target_block = block_to.min(chain_tip);

        let page_end_block: BlockNumber = (block_from.as_u32() + Self::PAGINATION_BLOCK_LIMIT)
            .min(target_block.as_u32())
            .into();

        // Blocks are iterated in ascending order, so later blocks win per asset ID.
        let mut vault_patch = AccountVaultPatch::default();
        for block in self.mock_chain.read().proven_blocks() {
            let block_number = block.header().block_num();
            // Only include blocks in range [block_from, page_end_block]
            if block_number < block_from || block_number > page_end_block {
                continue;
            }

            for update in block
                .body()
                .updated_accounts()
                .iter()
                .filter(|block_acc_update| block_acc_update.account_id() == account_id)
            {
                let AccountUpdateDetails::Public(patch) = update.details().clone() else {
                    continue;
                };

                vault_patch.merge(patch.vault().clone());
            }
        }

        (chain_tip, page_end_block, vault_patch)
    }

    /// Retrieves transactions in a given block range that match the provided account IDs
    fn get_sync_transactions_request(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_ids: &[AccountId],
    ) -> Vec<TransactionRecord> {
        let mut transactions = Vec::new();
        for block in self.mock_chain.read().proven_blocks() {
            let block_number = block.header().block_num();
            if block_number < block_from || block_number > block_to {
                continue;
            }

            for transaction_header in block.body().transactions().as_slice() {
                if !account_ids.contains(&transaction_header.account_id()) {
                    continue;
                }

                let erased_output_notes = self.erased_notes.read().clone();

                transactions.push(TransactionRecord {
                    block_num: block_number,
                    transaction_header: transaction_header.clone(),
                    output_notes: vec![],
                    erased_output_notes,
                    consumed_note_refs: vec![],
                });
            }
        }

        transactions
    }

    /// Retrieves storage map updates in a given block range.
    ///
    /// This method tries to simulate pagination of the real node.
    fn get_sync_storage_maps_request(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_id: AccountId,
    ) -> (BlockNumber, BlockNumber, BTreeMap<StorageSlotName, StorageMapPatchEntries>) {
        let chain_tip = self.get_chain_tip_block_num();
        let target_block = block_to.min(chain_tip);

        let page_end_block: BlockNumber = (block_from.as_u32() + Self::PAGINATION_BLOCK_LIMIT)
            .min(target_block.as_u32())
            .into();

        // Blocks are iterated in ascending order, so later blocks win per `(slot, key)`.
        let mut map_entries: BTreeMap<StorageSlotName, StorageMapPatchEntries> = BTreeMap::new();
        for block in self.mock_chain.read().proven_blocks() {
            let block_number = block.header().block_num();
            // Only include blocks in range [block_from, page_end_block]
            if block_number < block_from || block_number > page_end_block {
                continue;
            }

            for update in block
                .body()
                .updated_accounts()
                .iter()
                .filter(|block_acc_update| block_acc_update.account_id() == account_id)
            {
                let AccountUpdateDetails::Public(patch) = update.details().clone() else {
                    continue;
                };

                for (slot_name, map_patch) in patch.storage().maps() {
                    if let Some(entries) = map_patch.entries() {
                        map_entries
                            .entry(slot_name.clone())
                            .or_default()
                            .as_map_mut()
                            .extend(entries.as_map().clone());
                    }
                }
            }
        }

        (chain_tip, page_end_block, map_entries)
    }

    pub fn get_available_notes(&self) -> Vec<MockChainNote> {
        self.mock_chain.read().committed_notes().values().cloned().collect()
    }

    pub fn get_public_available_notes(&self) -> Vec<MockChainNote> {
        self.mock_chain
            .read()
            .committed_notes()
            .values()
            .filter(|n| matches!(n, MockChainNote::Public(_, _)))
            .cloned()
            .collect()
    }

    pub fn advance_blocks(&self, num_blocks: u32) {
        let mut mock_chain = self.mock_chain.write();
        let block_num = mock_chain.latest_block_header().block_num();
        let snapshot = Arc::new(mock_chain.clone());
        mock_chain.prove_until_block(block_num + num_blocks).unwrap();
        self.historical_chains.write().insert(block_num, snapshot);
    }
}
#[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
#[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
impl NodeRpcClient for MockRpcApi {
    /// Always reports the commitment as unset, unlike a real client.
    ///
    /// A real client's RPC connection is its own, so whoever set the commitment also stored the
    /// header. Tests share one mock across clients with separate stores, where a commitment set by
    /// the first would stop every later client from storing genesis at all.
    fn has_genesis_commitment(&self) -> Option<Word> {
        None
    }

    async fn set_genesis_commitment(&self, _commitment: Word) -> Result<(), RpcError> {
        // The mock sends no request headers, so there is nothing to pin the commitment to.
        Ok(())
    }

    /// Returns note updates in the inclusive block range `[block_from, block_to]`. Only notes that
    /// match the provided tags will be returned, grouped by block.
    async fn sync_notes(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        note_tags: &BTreeSet<NoteTag>,
    ) -> Result<Vec<SyncNotesBlock>, RpcError> {
        let mut blocks_with_notes: BTreeMap<BlockNumber, BTreeMap<NoteId, CommittedNote>> =
            BTreeMap::new();
        for note in self.mock_chain.read().committed_notes().values() {
            let note_block = note.inclusion_proof().location().block_num();
            if note_tags.contains(&note.metadata().tag())
                && note_block >= block_from
                && note_block <= block_to
            {
                let mut committed =
                    CommittedNote::new(note.id(), *note.metadata(), note.inclusion_proof().clone());
                // Mirror the node: a single-word attachment is sent verbatim and the record is
                // complete. A larger one is sent as a commitment only.
                let attachments = note.attachments();
                if attachments.iter().all(|attachment| attachment.num_words() == 1) {
                    committed = committed
                        .with_attachments(attachments.clone())
                        .expect("the note's own attachments match its commitment");
                }
                blocks_with_notes.entry(note_block).or_default().insert(note.id(), committed);
            }
        }

        Ok(blocks_with_notes
            .into_iter()
            .map(|(bn, notes)| {
                let block_header = self.get_block_by_num(bn);
                let mmr_path =
                    self.sync_notes_mmr_path_overrides.read().get(&bn).cloned().unwrap_or_else(
                        || self.get_mmr().open(bn.as_usize()).unwrap().merkle_path().clone(),
                    );
                SyncNotesBlock { block_header, mmr_path, notes }
            })
            .collect())
    }

    async fn sync_chain_mmr(
        &self,
        current_block_height: BlockNumber,
        upper_bound: SyncTarget,
    ) -> Result<ChainMmrInfo, RpcError> {
        let chain_tip = self.get_chain_tip_block_num();
        // The mock chain doesn't distinguish committed vs proven tips.
        let target_block = match upper_bound {
            SyncTarget::CommittedChainTip | SyncTarget::ProvenChainTip => chain_tip,
        };

        let from_forest = if current_block_height == target_block {
            target_block.as_usize()
        } else {
            current_block_height.as_u32() as usize + 1
        };

        let mmr_delta = self
            .get_mmr()
            .get_delta(
                Forest::new(from_forest).unwrap(),
                Forest::new(target_block.as_usize()).unwrap(),
            )
            .unwrap();

        let block_header = self.get_block_by_num(target_block);
        let block_signatures = self
            .mock_chain
            .read()
            .proven_blocks()
            .iter()
            .find(|block| block.header().block_num() == target_block)
            .expect("the mock chain contains the target block")
            .signatures()
            .clone();

        // Mirrors the node: send the configuration when the caller starts at genesis, or when the
        // commitment changed over the range. A caller already at the target gets nothing.
        let protocol_config = if current_block_height == BlockNumber::GENESIS {
            Some(self.protocol_config())
        } else if current_block_height == target_block {
            None
        } else {
            let commitment_at_start =
                self.get_block_by_num(current_block_height).protocol_config_commitment();
            (commitment_at_start != block_header.protocol_config_commitment())
                .then(|| self.protocol_config())
        };

        Ok(ChainMmrInfo {
            block_from: current_block_height,
            block_to: target_block,
            mmr_delta,
            block_header,
            protocol_config,
            block_signatures,
        })
    }

    /// Retrieves the block header for the specified block number. If the block number is not
    /// provided, the chain tip block header will be returned.
    async fn get_block_header_by_number(
        &self,
        block_num: Option<BlockNumber>,
        include_mmr_proof: bool,
    ) -> Result<(BlockHeader, Option<MmrProof>), RpcError> {
        self.block_header_requests
            .write()
            .push(BlockHeaderRequest { block_num, include_mmr_proof });

        let block = if let Some(block_num) = block_num {
            self.mock_chain.read().block_header(block_num.as_usize())
        } else {
            self.mock_chain.read().latest_block_header()
        };

        let mmr_proof = if include_mmr_proof {
            Some(self.get_mmr().open(block_num.unwrap().as_usize()).unwrap())
        } else {
            None
        };

        Ok((block, mmr_proof))
    }

    /// Returns the node's tracked notes that match the provided note IDs.
    async fn get_notes_by_id(&self, note_ids: &[NoteId]) -> Result<Vec<FetchedNote>, RpcError> {
        self.get_notes_by_id_calls.fetch_add(1, Ordering::Relaxed);

        let notes = self.mock_chain.read().committed_notes().clone();

        let hit_notes = note_ids.iter().filter_map(|id| notes.get(id));
        let mut return_notes = vec![];
        for note in hit_notes {
            let fetched_note = match note {
                MockChainNote::Private(note_id, note_metadata, _, note_inclusion_proof) => {
                    let attachments = self
                        .private_note_attachments
                        .read()
                        .get(note_id)
                        .cloned()
                        .unwrap_or_else(NoteAttachments::empty);
                    FetchedNote::Private(
                        *note_id,
                        *note_metadata,
                        attachments,
                        note_inclusion_proof.clone(),
                    )
                },
                MockChainNote::Public(note, note_inclusion_proof) => {
                    FetchedNote::Public(note.clone(), note_inclusion_proof.clone())
                },
            };
            return_notes.push(fetched_note);
        }
        Ok(return_notes)
    }

    /// The mock does not serve the encryption key. Verifying an attestation needs a validator
    /// signature the mock chain cannot produce, so tests that submit transactions seed the key
    /// directly through `Client::seed_transaction_encryption_key` instead.
    async fn get_transaction_encryption_key(
        &self,
    ) -> Result<AttestedTransactionEncryptionKey, RpcError> {
        Err(RpcError::TransactionEncryptionKeyRejected(
            "the mock RPC client does not serve a transaction encryption key".into(),
        ))
    }

    /// Simulates the submission of a proven transaction to the node. This will create a new block
    /// just for the new transaction and return the block number of the newly created block.
    async fn submit_proven_transaction(
        &self,
        proven_transaction: &ProvenTransaction,
        _sealed_transaction_inputs: SealedTransactionInputs, /* Unnecessary for testing client
                                                              * itself. */
    ) -> Result<BlockNumber, RpcError> {
        if let Some(error) = self.take_failure(RpcEndpoint::SubmitProvenTx) {
            return Err(error);
        }

        // Record private-note attachment content the way a real node does: attachments are stored
        // on-chain even for private notes, so `get_notes_by_id` must be able to serve them. The
        // mock chain itself only keeps private note headers.
        for note in proven_transaction.output_notes().iter() {
            if let OutputNote::Private(private_note) = note
                && !private_note.attachments().is_empty()
            {
                self.private_note_attachments
                    .write()
                    .insert(private_note.id(), private_note.attachments().clone());
            }
        }

        {
            let mut mock_chain = self.mock_chain.write();
            mock_chain.add_pending_proven_transaction(proven_transaction.clone());
        };

        let block_num = self.get_chain_tip_block_num();

        Ok(block_num)
    }

    /// Simulates the submission of a proven batch to the node by adding it to the mock chain's
    /// pending batches. The `proposed_batch` argument is accepted to match the trait signature but
    /// is unused: the mock relies on the `ProvenBatch` alone. The sealed inputs are recorded rather
    /// than decrypted, so a test can inspect what each attempt sent.
    async fn submit_proven_batch(
        &self,
        proven_batch: &ProvenBatch,
        _proposed_batch: &ProposedBatch,
        sealed_transaction_inputs: Vec<SealedTransactionInputs>,
    ) -> Result<BlockNumber, RpcError> {
        // Recorded before the staged failure is served: a submission whose response is lost still
        // reached the node, so a test can compare what that attempt sent against the retry.
        self.submitted_batch_sealed_inputs.write().push(sealed_transaction_inputs);

        if let Some(error) = self.take_failure(RpcEndpoint::SubmitProvenBatch) {
            return Err(error);
        }

        let mut mock_chain = self.mock_chain.write();
        mock_chain.add_pending_batch(proven_batch.clone());
        drop(mock_chain);

        let block_num = self.get_chain_tip_block_num();

        Ok(block_num)
    }

    /// Returns the account proof for the specified account. The `known_code` and `vault` fields are
    /// ignored: full account data is returned, with truncation flags set when it exceeds
    /// `oversize_threshold`.
    async fn get_account(
        &self,
        account_id: AccountId,
        request: GetAccountRequest,
    ) -> Result<(BlockNumber, AccountProof), RpcError> {
        self.get_account_calls.fetch_add(1, Ordering::Relaxed);

        if let Some(error) = self.take_failure(RpcEndpoint::GetAccount) {
            return Err(error);
        }

        let current_chain = self.mock_chain.read();
        let current_block_number = current_chain.latest_block_header().block_num();
        let block_number = match request.at {
            AccountStateAt::Block(number) => number,
            AccountStateAt::ChainTip => current_block_number,
        };
        let historical_chain = match request.at {
            AccountStateAt::Block(_) if block_number != current_block_number => Some(
                self.historical_chains.read().get(&block_number).cloned().ok_or_else(|| {
                    RpcError::InvalidResponse(alloc::format!(
                        "no mock chain snapshot at block {block_number}"
                    ))
                })?,
            ),
            AccountStateAt::ChainTip | AccountStateAt::Block(_) => None,
        };
        let mock_chain = historical_chain.as_deref().unwrap_or(&*current_chain);

        let headers = if account_id.is_public() {
            let account = mock_chain.committed_account(account_id).unwrap();

            // `All` enumerates the account's map slots directly — the mock can introspect the
            // account, so it simulates the (not-yet-on-the-wire) "all storage maps" request. A slot
            // maps to the keys requested for it, empty meaning "every entry".
            let requested_slots: Vec<(StorageSlotName, Vec<StorageMapKey>)> = match &request.storage
            {
                StorageMapFetch::Skip => Vec::new(),
                StorageMapFetch::Slots(reqs) => {
                    reqs.inner().iter().map(|(name, keys)| (name.clone(), keys.clone())).collect()
                },
                StorageMapFetch::All => account
                    .storage()
                    .to_header()
                    .slots()
                    .filter(|slot| slot.slot_type() == StorageSlotType::Map)
                    .map(|slot| (slot.name().clone(), Vec::new()))
                    .collect(),
            };

            let mut map_details = vec![];
            for (slot_name, requested_keys) in &requested_slots {
                if let Some(StorageSlotContent::Map(storage_map)) =
                    account.storage().get(slot_name).map(StorageSlot::content)
                {
                    // Mirror the node: named keys come back as one partial SMT covering them, and
                    // an empty key list comes back as the whole map, or as `LimitExceeded` once it
                    // grows past the threshold.
                    let entries = if requested_keys.is_empty() {
                        let entries: Vec<StorageMapEntry> = storage_map
                            .entries()
                            .map(|(key, value)| StorageMapEntry { key: *key, value: *value })
                            .collect();

                        if entries.len() > self.oversize_threshold {
                            StorageMapEntries::LimitExceeded
                        } else {
                            StorageMapEntries::AllEntries(entries)
                        }
                    } else {
                        let partial_smt = PartialSmt::from_proofs(
                            requested_keys.iter().map(|key| storage_map.open(key).into()),
                        )
                        .expect("proofs from one map share a root");

                        StorageMapEntries::PartialMap {
                            map_keys: requested_keys.clone(),
                            partial_smt,
                        }
                    };

                    map_details
                        .push(AccountStorageMapDetails { slot_name: slot_name.clone(), entries });
                } else {
                    panic!("Storage slot {slot_name} is not a map");
                }
            }

            let storage_details = AccountStorageDetails {
                header: account.storage().to_header(),
                map_details,
            };

            // Mirror the node: `Skip` sends no assets, and `IfChangedFrom` omits them when the
            // account's vault root already equals the sent commitment.
            let include_assets = match request.vault {
                VaultFetch::Skip => false,
                VaultFetch::Always => true,
                VaultFetch::IfChangedFrom(root) => root != account.vault().root(),
            };
            let mut assets = vec![];
            if include_assets {
                for asset in account.vault().assets() {
                    assets.push(asset);
                }
            }
            let vault_details = AccountVaultDetails {
                too_many_assets: assets.len() > self.oversize_threshold,
                assets,
            };

            Some(AccountDetails {
                header: account.into(),
                storage_details,
                code: account.code().clone(),
                vault_details,
            })
        } else {
            None
        };

        let witness = mock_chain.account_tree().open(account_id);

        let proof = AccountProof::new(witness, headers).unwrap();

        Ok((block_number, proof))
    }

    async fn register_account(
        &self,
        invitation_code: &str,
        account_id: AccountId,
    ) -> Result<(), RpcError> {
        if let Some(error) = self.take_failure(RpcEndpoint::RegisterAccount) {
            return Err(error);
        }

        // The mock holds no invitations, so it accepts any code and records the pair. Stage a
        // failure with `fail_next_call` to exercise a rejection.
        self.registered_accounts
            .write()
            .insert(account_id, String::from(invitation_code));

        Ok(())
    }

    async fn is_account_allowed(&self, account_id: AccountId) -> Result<bool, RpcError> {
        self.is_account_allowed_calls.fetch_add(1, Ordering::Relaxed);

        if let Some(error) = self.take_failure(RpcEndpoint::IsAccountAllowed) {
            return Err(error);
        }

        // A node that does not enforce the allowlist allows every account. Call
        // `enforce_account_allowlist` to answer from the recorded registrations instead.
        if !self.allowlist_enforced.load(Ordering::SeqCst) {
            return Ok(true);
        }

        Ok(self.registered_accounts.read().contains_key(&account_id))
    }

    /// Returns the nullifiers created after the specified block number that match the provided
    /// prefixes.
    async fn sync_nullifiers(
        &self,
        prefixes: &[u16],
        block_from: BlockNumber,
        block_to: BlockNumber,
    ) -> Result<Vec<NullifierUpdate>, RpcError> {
        let nullifiers = self
            .mock_chain
            .read()
            .nullifier_tree()
            .entries()
            .filter_map(|(nullifier, block_num)| {
                let within_range = block_num >= block_from && block_num <= block_to;

                if prefixes.contains(&nullifier.prefix()) && within_range {
                    Some(NullifierUpdate { nullifier, block_num })
                } else {
                    None
                }
            })
            .collect::<Vec<_>>();

        Ok(nullifiers)
    }

    async fn get_block_by_number(
        &self,
        block_num: BlockNumber,
        include_proof: bool,
    ) -> Result<(SignedBlock, Option<ExecutionProof>), RpcError> {
        let block = self
            .mock_chain
            .read()
            .proven_blocks()
            .iter()
            .find(|b| b.header().block_num() == block_num)
            .unwrap()
            .clone();
        let (header, body, signatures, proof) = block.into_parts();

        Ok((
            SignedBlock::new_unchecked(header, body, signatures),
            include_proof.then_some(proof),
        ))
    }

    async fn get_note_script_by_root(&self, root: Word) -> Result<Option<NoteScript>, RpcError> {
        let script = self
            .get_available_notes()
            .iter()
            .filter_map(|note| note.note())
            .find(|n| Word::from(n.script().root()) == root)
            .map(|n| n.script().clone());

        Ok(script)
    }

    async fn sync_storage_maps(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_id: AccountId,
    ) -> Result<StorageMapInfo, RpcError> {
        let mut map_entries: BTreeMap<StorageSlotName, StorageMapPatchEntries> = BTreeMap::new();
        let mut current_block_from = block_from;
        let chain_tip = self.get_chain_tip_block_num();
        let target_block = block_to.min(chain_tip);

        loop {
            let (page_chain_tip, page_block_number, page_entries) =
                self.get_sync_storage_maps_request(current_block_from, block_to, account_id);
            for (slot_name, entries) in page_entries {
                map_entries
                    .entry(slot_name)
                    .or_default()
                    .as_map_mut()
                    .extend(entries.into_map());
            }

            if page_block_number >= target_block {
                return Ok(StorageMapInfo {
                    chain_tip: page_chain_tip,
                    block_number: page_block_number,
                    map_entries,
                });
            }

            current_block_from = (page_block_number.as_u32() + 1).into();
        }
    }

    async fn sync_account_vault(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_id: AccountId,
    ) -> Result<AccountVaultInfo, RpcError> {
        let mut vault_patch = AccountVaultPatch::default();
        let mut current_block_from = block_from;
        let chain_tip = self.get_chain_tip_block_num();
        let target_block = block_to.min(chain_tip);

        loop {
            let (page_chain_tip, page_block_number, page_patch) =
                self.get_sync_account_vault_request(current_block_from, block_to, account_id);
            vault_patch.merge(page_patch);

            if page_block_number >= target_block {
                return Ok(AccountVaultInfo {
                    chain_tip: page_chain_tip,
                    block_number: page_block_number,
                    vault_patch,
                });
            }

            current_block_from = (page_block_number.as_u32() + 1).into();
        }
    }

    async fn sync_transactions(
        &self,
        block_from: BlockNumber,
        block_to: BlockNumber,
        account_ids: Vec<AccountId>,
    ) -> Result<Vec<TransactionRecord>, RpcError> {
        Ok(self.get_sync_transactions_request(block_from, block_to, &account_ids))
    }

    async fn get_network_id(&self) -> Result<NetworkId, RpcError> {
        Ok(NetworkId::Testnet)
    }

    async fn get_rpc_limits(&self) -> Result<crate::rpc::RpcLimits, RpcError> {
        Ok(crate::rpc::RpcLimits::default())
    }

    fn has_rpc_limits(&self) -> Option<crate::rpc::RpcLimits> {
        None
    }

    async fn set_rpc_limits(&self, _limits: crate::rpc::RpcLimits) {
        // No-op for mock client
    }

    async fn get_status_unversioned(&self) -> Result<RpcStatusInfo, RpcError> {
        Ok(RpcStatusInfo {
            version: env!("CARGO_PKG_VERSION").into(),
            genesis_commitment: None,
            chain_tip: 0,
            block_producer: None,
        })
    }

    async fn get_network_note_status(
        &self,
        _note_id: NoteId,
    ) -> Result<NetworkNoteStatusInfo, RpcError> {
        todo!("We need to check if we want to implement this for the mockchain");
    }
}

// CONVERSIONS
// ================================================================================================

impl From<MockChain> for MockRpcApi {
    fn from(mock_chain: MockChain) -> Self {
        MockRpcApi::new(mock_chain)
    }
}

// HELPERS
// ================================================================================================

fn build_account_updates(
    mock_chain: &MockChain,
) -> BTreeMap<BlockNumber, BTreeMap<AccountId, Word>> {
    let mut account_commitment_updates = BTreeMap::new();
    for block in mock_chain.proven_blocks() {
        let block_num = block.header().block_num();
        let mut updates = BTreeMap::new();

        for update in block.body().updated_accounts() {
            updates.insert(update.account_id(), update.final_state_commitment());
        }

        if updates.is_empty() {
            continue;
        }

        account_commitment_updates.insert(block_num, updates);
    }
    account_commitment_updates
}