hiero-sdk 0.38.1

// SPDX-License-Identifier: Apache-2.0

use std::borrow::Cow;
use std::collections::HashMap;
use std::fmt;
use std::fmt::{
    Debug,
    Formatter,
};
use std::num::NonZeroUsize;

use hiero_sdk_proto::services;
use prost::Message;
use time::Duration;
use triomphe::Arc;

use crate::custom_fee_limit::CustomFeeLimit;
use crate::downcast::DowncastOwned;
use crate::execute::execute;
use crate::signer::AnySigner;
use crate::{
    AccountId,
    Client,
    Error,
    Hbar,
    Operator,
    PrivateKey,
    PublicKey,
    ScheduleCreateTransaction,
    ToProtobuf,
    TransactionHash,
    TransactionId,
    TransactionResponse,
    ValidateChecksums,
};

mod any;
mod chunked;
mod cost;
mod execute;
mod protobuf;
mod source;
#[cfg(test)]
mod tests;

pub use any::AnyTransaction;
pub(crate) use any::AnyTransactionData;
pub(crate) use chunked::{
    ChunkData,
    ChunkInfo,
    ChunkedTransactionData,
};
pub(crate) use cost::CostTransaction;
pub(crate) use execute::{
    TransactionData,
    TransactionExecute,
    TransactionExecuteChunked,
};
pub(crate) use protobuf::{
    ToSchedulableTransactionDataProtobuf,
    ToTransactionDataProtobuf,
};
pub(crate) use source::TransactionSources;

const DEFAULT_TRANSACTION_VALID_DURATION: Duration = Duration::seconds(120);

/// A transaction that can be executed on the Hiero network.
#[derive(Clone)]
pub struct Transaction<D> {
    body: TransactionBody<D>,

    signers: Vec<AnySigner>,

    sources: Option<TransactionSources>,
}

#[derive(Debug, Default, Clone)]
pub(crate) struct TransactionBody<D> {
    pub(crate) data: D,

    pub(crate) node_account_ids: Option<Vec<AccountId>>,

    pub(crate) transaction_valid_duration: Option<Duration>,

    pub(crate) max_transaction_fee: Option<Hbar>,

    pub(crate) transaction_memo: String,

    pub(crate) transaction_id: Option<TransactionId>,

    pub(crate) operator: Option<Arc<Operator>>,

    pub(crate) is_frozen: bool,

    pub(crate) regenerate_transaction_id: Option<bool>,

    /// The maximum custom fee that the user is willing to pay for the message.
    /// If left empty, the user is willing to pay any custom fee.
    /// If used with a transaction type that does not support custom fee limits, the transaction will fail.
    pub(crate) custom_fee_limits: Vec<CustomFeeLimit>,
}

impl<D> Default for Transaction<D>
where
    D: Default,
{
    fn default() -> Self {
        Self {
            body: TransactionBody {
                data: D::default(),
                node_account_ids: None,
                transaction_valid_duration: None,
                max_transaction_fee: None,
                transaction_memo: String::new(),
                transaction_id: None,
                operator: None,
                is_frozen: false,
                regenerate_transaction_id: None,
                custom_fee_limits: Vec::new(),
            },
            signers: Vec::new(),
            sources: None,
        }
    }
}

impl<D> Debug for Transaction<D>
where
    D: Debug,
{
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        f.debug_struct("Transaction").field("body", &self.body).finish()
    }
}

impl<D> Transaction<D>
where
    D: Default,
{
    /// Create a new default transaction.
    ///
    /// Does the same thing as [`default`](Self::default)
    #[inline]
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }
}

impl<D> Transaction<D> {
    pub(crate) fn from_parts(body: TransactionBody<D>, signers: Vec<AnySigner>) -> Self {
        Self { body, signers, sources: None }
    }

    pub(crate) fn is_frozen(&self) -> bool {
        self.body.is_frozen
    }

    pub(crate) fn signers(&self) -> impl Iterator<Item = &AnySigner> {
        self.signers.iter()
    }

    pub(crate) fn sources(&self) -> Option<&TransactionSources> {
        self.sources.as_ref()
    }

    fn signed_sources(&self) -> Option<Cow<'_, TransactionSources>> {
        self.sources().map(|it| it.sign_with(&self.signers))
    }

    /// # Panics
    /// If `self.is_frozen()`.
    #[track_caller]
    pub(crate) fn require_not_frozen(&self) {
        assert!(
            !self.is_frozen(),
            "transaction is immutable; it has at least one signature or has been explicitly frozen"
        );
    }

    /// # Panics
    /// If `self.is_frozen()`.
    pub(crate) fn body_mut(&mut self) -> &mut TransactionBody<D> {
        self.require_not_frozen();
        &mut self.body
    }

    pub(crate) fn into_body(self) -> TransactionBody<D> {
        self.body
    }

    #[inline(always)]
    pub(crate) fn data(&self) -> &D {
        &self.body.data
    }

    /// # Panics
    /// If `self.is_frozen()`.
    pub(crate) fn data_mut(&mut self) -> &mut D {
        self.require_not_frozen();
        &mut self.body.data
    }

    /// Returns the account IDs of the nodes that this transaction may be submitted to.
    ///
    /// `None` means any node configured on the client.
    #[must_use]
    pub fn get_node_account_ids(&self) -> Option<&[AccountId]> {
        self.body.node_account_ids.as_deref()
    }

    /// Sets the account IDs of the nodes that this transaction may be submitted to.
    ///
    /// Defaults to the full list of nodes configured on the client.
    #[track_caller]
    pub fn node_account_ids(&mut self, ids: impl IntoIterator<Item = AccountId>) -> &mut Self {
        let nodes: Vec<_> = ids.into_iter().collect();

        if nodes.is_empty() {
            log::warn!("Nodes list is empty, ignoring setter");
        } else {
            self.body_mut().node_account_ids = Some(nodes);
        }

        self
    }

    /// Returns the duration that this transaction is valid for, once finalized and signed.
    #[must_use]
    pub fn get_transaction_valid_duration(&self) -> Option<Duration> {
        self.body.transaction_valid_duration
    }

    /// Sets the duration that this transaction is valid for, once finalized and signed.
    ///
    /// Defaults to 120 seconds (or two minutes).
    pub fn transaction_valid_duration(&mut self, duration: Duration) -> &mut Self {
        self.body_mut().transaction_valid_duration = Some(duration);
        self
    }

    /// Returns the maximum transaction fee the paying account is willing to pay.
    #[must_use]
    pub fn get_max_transaction_fee(&self) -> Option<Hbar> {
        self.body.max_transaction_fee
    }

    /// Sets the maximum transaction fee the paying account is willing to pay.
    pub fn max_transaction_fee(&mut self, fee: Hbar) -> &mut Self {
        self.body_mut().max_transaction_fee = Some(fee);
        self
    }

    /// Returns the custom fee limits for the transaction.
    #[must_use]
    pub fn get_custom_fee_limits(&self) -> &[CustomFeeLimit] {
        &self.body.custom_fee_limits
    }

    /// Sets the custom fee limits for the transaction.
    pub fn custom_fee_limits(
        &mut self,
        limits: impl IntoIterator<Item = CustomFeeLimit>,
    ) -> &mut Self {
        self.body_mut().custom_fee_limits = limits.into_iter().collect();
        self
    }

    /// Adds a custom fee limit to the transaction.
    pub fn add_custom_fee_limit(&mut self, limit: CustomFeeLimit) -> &mut Self {
        self.body_mut().custom_fee_limits.push(limit);
        self
    }

    /// Removes all custom fee limits for the transaction.
    pub fn clear_custom_fee_limits(&mut self) -> &mut Self {
        self.body_mut().custom_fee_limits.clear();
        self
    }

    /// Sets a note / description that should be recorded in the transaction record.
    ///
    /// Maximum length of 100 characters.
    #[must_use]
    pub fn get_transaction_memo(&self) -> &str {
        &self.body.transaction_memo
    }

    /// Sets a note or description that should be recorded in the transaction record.
    ///
    /// Maximum length of 100 characters.
    pub fn transaction_memo(&mut self, memo: impl AsRef<str>) -> &mut Self {
        self.body_mut().transaction_memo = memo.as_ref().to_owned();
        self
    }

    /// Returns the explicit transaction ID to use to identify this transaction.
    ///
    /// Overrides the payer account defined on this transaction or on the client.
    #[must_use]
    pub fn get_transaction_id(&self) -> Option<TransactionId> {
        self.body.transaction_id
    }

    /// Sets an explicit transaction ID to use to identify this transaction.
    ///
    /// Overrides the payer account defined on this transaction or on the client.
    pub fn transaction_id(&mut self, id: TransactionId) -> &mut Self {
        self.body_mut().transaction_id = Some(id);
        self
    }

    /// Sign the transaction.
    pub fn sign(&mut self, private_key: PrivateKey) -> &mut Self {
        self.sign_signer(AnySigner::PrivateKey(private_key))
    }

    /// Sign the transaction.
    pub fn sign_with<F: Fn(&[u8]) -> Vec<u8> + Send + Sync + 'static>(
        &mut self,
        public_key: PublicKey,
        signer: F,
    ) -> &mut Self {
        self.sign_signer(AnySigner::arbitrary(Box::new(public_key), signer))
    }

    pub(crate) fn sign_signer(&mut self, signer: AnySigner) -> &mut Self {
        // We're _supposed_ to require frozen here, but really there's no reason I can think of to do that.

        // skip the signer if we already have it.
        if self.signers.iter().any(|it| it.public_key() == signer.public_key()) {
            return self;
        }

        self.signers.push(signer);
        self
    }
}

impl<D: ChunkedTransactionData> Transaction<D> {
    /// Returns the maximum number of chunks this transaction will be split into.
    #[must_use]
    pub fn get_max_chunks(&self) -> usize {
        self.data().chunk_data().max_chunks
    }

    /// Sets the maximum number of chunks this transaction will be split into.
    pub fn max_chunks(&mut self, max_chunks: usize) -> &mut Self {
        self.data_mut().chunk_data_mut().max_chunks = max_chunks;

        self
    }

    // todo: just return a `NonZeroUsize` instead? Take something along the lines of a `u32`?
    /// Returns the maximum size of any chunk.
    pub fn get_chunk_size(&self) -> usize {
        self.data().chunk_data().chunk_size.get()
    }

    // todo: just take a `NonZeroUsize` instead? Take something along the lines of a `u32`?
    /// Sets the maximum size of any chunk.
    ///
    /// # Panics
    /// If `size` == 0
    pub fn chunk_size(&mut self, size: usize) -> &mut Self {
        let Some(size) = NonZeroUsize::new(size) else { panic!("Cannot set chunk-size to zero") };

        self.data_mut().chunk_data_mut().chunk_size = size;

        self
    }

    /// Returns whether or not the transaction ID should be refreshed if a [`Status::TransactionExpired`](crate::Status::TransactionExpired) occurs.
    ///
    /// By default, the value on Client will be used.
    ///
    /// Note: Some operations forcibly disable transaction ID regeneration, such as setting the transaction ID explicitly.
    pub fn get_regenerate_transaction_id(&self) -> Option<bool> {
        self.body.regenerate_transaction_id
    }

    /// Sets whether or not the transaction ID should be refreshed if a [`Status::TransactionExpired`](crate::Status::TransactionExpired) occurs.
    ///
    /// Various operations such as [`add_signature`](Self::add_signature) can forcibly disable transaction ID regeneration.
    pub fn regenerate_transaction_id(&mut self, regenerate_transaction_id: bool) -> &mut Self {
        self.body_mut().regenerate_transaction_id = Some(regenerate_transaction_id);

        self
    }
}

impl<D: ValidateChecksums> Transaction<D> {
    /// Freeze the transaction so that no further modifications can be made.
    ///
    /// # Errors
    /// - [`Error::FreezeUnsetNodeAccountIds`] if no [`node_account_ids`](Self::node_account_ids) were set.
    ///
    /// # Panics
    /// - If `node_account_ids` is explicitly set to empty (IE: `tx.node_account_ids([]).freeze_with(None)`).
    pub fn freeze(&mut self) -> crate::Result<&mut Self> {
        self.freeze_with(None)
    }

    /// Freeze the transaction so that no further modifications can be made.
    ///
    /// # Errors
    /// - [`Error::FreezeUnsetNodeAccountIds`] if no [`node_account_ids`](Self::node_account_ids) were set and `client.is_none()`.
    ///
    /// # Panics
    /// - If `node_account_ids` is explicitly set to empty (IE: `tx.node_account_ids([]).freeze_with(None)`).
    pub fn freeze_with<'a>(
        &mut self,
        client: impl Into<Option<&'a Client>>,
    ) -> crate::Result<&mut Self> {
        if self.is_frozen() {
            return Ok(self);
        }
        let client: Option<&Client> = client.into();

        // set transaction id if not set based on client operator
        if self.get_transaction_id().is_none() {
            let operator: Arc<Operator> =
                client.and_then(Client::full_load_operator).expect("Client must have an operator");
            let transaction_id = TransactionId::generate(operator.account_id);
            self.transaction_id(transaction_id);
        }

        let node_account_ids = match &self.body.node_account_ids {
            // the clone here is the lesser of two evils.
            Some(it) => {
                assert!(!it.is_empty());
                it.clone()
            }
            #[allow(clippy::missing_panics_doc)]
            None => {
                let nodes = client
                    .ok_or(Error::FreezeUnsetNodeAccountIds)?
                    .net()
                    .0
                    .load()
                    .random_node_ids();
                assert!(!nodes.is_empty(), "BUG: Client didn't give any nodes (all unhealthy)");

                nodes
            }
        };

        // note to reviewer: this is intentionally still an option, fallback is used later, swift doesn't *have* default max transaction fee and fixing it is a massive PITA.
        let max_transaction_fee = self.body.max_transaction_fee.or_else(|| {
            // no max has been set on the *transaction*
            // check if there is a global max set on the client
            client.and_then(Client::default_max_transaction_fee)
        });

        let custom_fee_limits = self.body.custom_fee_limits.clone();

        let operator = client.and_then(Client::full_load_operator);

        // note: yes, there's an `Some(opt.unwrap())`, this is INTENTIONAL.
        self.body.node_account_ids = Some(node_account_ids);
        self.body.max_transaction_fee = max_transaction_fee;
        self.body.operator = operator;
        self.body.is_frozen = true;
        self.body.custom_fee_limits = custom_fee_limits;

        if let Some(client) = client {
            if client.auto_validate_checksums() {
                let ledger_id = client.ledger_id_internal();
                let ledger_id = ledger_id
                    .as_ref()
                    .expect("Client had auto_validate_checksums enabled but no ledger ID");

                self.validate_checksums(ledger_id.as_ref_ledger_id())?;
            }
        }

        Ok(self)
    }

    /// Sign the transaction with the `client`'s operator.
    ///
    /// # Errors
    /// - If [`freeze_with`](Self::freeze_with) would error for this transaction.
    ///
    /// # Panics
    /// If `client` has no operator.
    pub fn sign_with_operator(&mut self, client: &Client) -> crate::Result<&mut Self> {
        let Some(op) = client.full_load_operator() else { panic!("Client had no operator") };

        self.freeze_with(client)?;

        self.sign_signer(op.signer.clone());

        self.body.operator = Some(op);

        Ok(self)
    }
}

impl<D: TransactionExecute> Transaction<D> {
    /// # Errors
    /// - If the transaction needs multiple chunks, or has no explicit transaction ID *and* `self.operator` is not set.
    ///
    /// # Panics
    /// - If `!self.is_frozen()`
    fn make_transaction_list(&self) -> crate::Result<Vec<services::Transaction>> {
        if self.data().maybe_chunk_data().is_some() {
            self.make_transaction_list_chunked()
        } else {
            self.make_transaction_list_non_chunked()
        }
    }

    pub(crate) fn make_sources(&self) -> crate::Result<Cow<'_, TransactionSources>> {
        if let Some(sources) = self.signed_sources() {
            return Ok(sources);
        }

        return Ok(Cow::Owned(TransactionSources::new(self.make_transaction_list()?).unwrap()));
    }

    /// Convert `self` to protobuf encoded bytes.
    ///
    /// # Errors
    /// - If `freeze_with` wasn't called with an operator.
    ///
    /// # Panics
    /// - If `!self.is_frozen()`.
    pub fn to_bytes(&self) -> crate::Result<Vec<u8>> {
        let transaction_list = self.make_transaction_list().unwrap();
        Ok(hiero_sdk_proto::sdk::TransactionList { transaction_list }.encode_to_vec())
    }

    pub(crate) fn add_signature_signer(&mut self, signer: &AnySigner) -> Vec<u8> {
        assert!(self.is_frozen());

        // note: the following pair of cheecks are for more detailed panic messages
        // IE, they should *hopefully* be tripped first
        assert_eq!(
            self.body.node_account_ids.as_deref().map_or(0, <[AccountId]>::len),
            1,
            "cannot manually add a signature to a transaction with multiple nodes"
        );

        if let Some(chunk_data) = self.data().maybe_chunk_data() {
            assert!(
                chunk_data.used_chunks() <= 1,
                "cannot manually add a signature to a chunked transaction with multiple chunks (message length `{}` > chunk size `{}`)",
                chunk_data.data.len(),
                chunk_data.chunk_size
            );
        }

        let sources = self.make_sources().unwrap();

        // this is the only check that is for correctness rather than debugability.
        assert!(sources.transactions().len() == 1);

        let sources = sources.sign_with(std::slice::from_ref(signer));

        // hack: I don't care about perf here.
        let ret = signer.sign(&sources.signed_transactions()[0].body_bytes);

        // if we have a `Cow::Borrowed` that'd mean there was no modification
        if let Cow::Owned(sources) = sources {
            self.sources = Some(sources);
        }

        ret.1
    }

    // todo: should this return `Result<&mut Self>`?
    /// Adds a signature directly to `self`.
    ///
    /// Only use this as a last resort.
    ///
    /// This forcibly disables transaction ID regeneration.
    pub fn add_signature(&mut self, pk: PublicKey, signature: Vec<u8>) -> &mut Self {
        self.add_signature_signer(&AnySigner::arbitrary(Box::new(pk), move |_| signature.clone()));

        self
    }

    /// # Panics
    /// panics if the transaction is not schedulable, a transaction can be non-schedulable due to:
    /// - if `self.is_frozen`
    /// - being a transaction kind that's non-schedulable, IE, `EthereumTransaction`, or
    /// - being a chunked transaction with multiple chunks.
    pub fn schedule(self) -> ScheduleCreateTransaction {
        self.require_not_frozen();
        assert!(self.get_node_account_ids().is_none(), "The underlying transaction for a scheduled transaction cannot have node account IDs set");

        let mut transaction = ScheduleCreateTransaction::new();

        if let Some(transaction_id) = self.get_transaction_id() {
            transaction.transaction_id(transaction_id);
        }

        transaction.scheduled_transaction(self);

        transaction
    }

    /// Get the hash for this transaction.
    ///
    /// Note: Calling this function _disables_ transaction ID regeneration.
    ///
    /// # Errors
    /// - [`Error::NoPayerAccountOrTransactionId`]
    ///     if `freeze_with` wasn't called with an operator and no transaction ID was set.
    ///
    /// # Panics
    /// - If `!self.is_frozen()`.
    pub fn get_transaction_hash(&mut self) -> crate::Result<TransactionHash> {
        // todo: error not frozen
        assert!(
            self.is_frozen(),
            "Transaction must be frozen before calling `get_transaction_hash`"
        );

        let sources = self.make_sources()?;

        let sources = match sources {
            Cow::Borrowed(it) => it,
            Cow::Owned(it) => &*self.sources.insert(it),
        };

        Ok(TransactionHash::new(&sources.transactions().first().unwrap().signed_transaction_bytes))
    }

    /// Get the hashes for this transaction.
    ///
    /// Note: Calling this function _disables_ transaction ID regeneration.
    ///
    /// # Errors
    /// - [`Error::NoPayerAccountOrTransactionId`]
    ///     if `freeze_with` wasn't called with an operator and no transaction ID was set.
    ///
    /// # Panics
    /// - If `!self.is_frozen()`.
    pub fn get_transaction_hash_per_node(
        &mut self,
    ) -> crate::Result<HashMap<AccountId, TransactionHash>> {
        // todo: error not frozen
        assert!(
            self.is_frozen(),
            "Transaction must be frozen before calling `get_transaction_hash`"
        );

        let sources = self.make_sources()?;

        let chunk = sources.chunks().next().unwrap();

        let iter = chunk
            .node_ids()
            .iter()
            .zip(chunk.transactions())
            .map(|(node, it)| (*node, TransactionHash::new(&it.signed_transaction_bytes)));

        Ok(iter.collect())
    }

    #[allow(deprecated)]
    fn make_transaction_list_chunked(&self) -> crate::Result<Vec<services::Transaction>> {
        // todo: fix this with chunked transactions.
        let used_chunks = self.data().maybe_chunk_data().map_or(1, ChunkData::used_chunks);
        let node_account_ids = self.body.node_account_ids.as_deref().unwrap();

        let mut transaction_list = Vec::with_capacity(used_chunks * node_account_ids.len());

        if node_account_ids.is_empty() {
            // Handle case with no node IDs
            transaction_list.push(self.create_transaction_for_node(None));
        } else {
            // Handle case with node IDs
            for node_account_id in node_account_ids {
                transaction_list.push(self.create_transaction_for_node(Some(node_account_id)));
            }
        }

        Ok(transaction_list)
    }

    #[allow(clippy::too_many_lines)]
    #[allow(deprecated)]
    fn make_transaction_list_non_chunked(&self) -> crate::Result<Vec<services::Transaction>> {
        let mut transaction_list = Vec::new();

        let node_account_ids = match &self.get_node_account_ids() {
            Some(ids) => ids.iter().collect::<Vec<_>>(),
            None => vec![], // Default if none specified
        };

        if node_account_ids.is_empty() {
            // Handle case with no node IDs
            transaction_list.push(self.create_transaction_for_node(None));
        } else {
            // Handle case with node IDs
            for node_account_id in node_account_ids {
                transaction_list.push(self.create_transaction_for_node(Some(node_account_id)));
            }
        }

        Ok(transaction_list)
    }

    /// Creates a transaction for a specific node and adds it to the transaction list
    fn create_transaction_for_node(&self, node_opt: Option<&AccountId>) -> services::Transaction {
        let transaction_body = services::TransactionBody {
            transaction_id: self.get_transaction_id().map(|id| id.to_protobuf()),
            generate_record: false,
            memo: self.body.transaction_memo.clone(),
            data: Some(self.body.data.to_transaction_data_protobuf(&ChunkInfo {
                current: 0,
                total: 1,
                initial_transaction_id: TransactionId::generate(AccountId::new(0, 0, 0)),
                current_transaction_id: TransactionId::generate(AccountId::new(0, 0, 0)),
                node_account_id: node_opt.cloned(),
            })),
            transaction_valid_duration: Some(
                self.get_transaction_valid_duration()
                    .unwrap_or_else(|| DEFAULT_TRANSACTION_VALID_DURATION)
                    .to_protobuf(),
            ),
            node_account_id: node_opt.map(|id| id.to_protobuf()),
            transaction_fee: self
                .body
                .max_transaction_fee
                .unwrap_or_else(|| self.body.data.default_max_transaction_fee())
                .to_tinybars() as u64,
            max_custom_fees: self.body.custom_fee_limits.to_protobuf(),
            batch_key: None, // todo: add batch key
        };

        let body_bytes = transaction_body.encode_to_vec();
        let mut signatures = Vec::with_capacity(1 + self.signers.len());

        if let Some(operator) = &self.body.operator {
            let operator_signature = operator.sign(&body_bytes);
            let (pk, sig) = operator_signature;
            signatures.push(services::SignaturePair {
                pub_key_prefix: pk.to_bytes_raw(),
                signature: Some(match pk.kind() {
                    crate::key::KeyKind::Ed25519 => {
                        services::signature_pair::Signature::Ed25519(sig)
                    }
                    crate::key::KeyKind::Ecdsa => {
                        services::signature_pair::Signature::EcdsaSecp256k1(sig)
                    }
                }),
            });
        }

        for signer in &self.signers {
            let public_key = signer.public_key().to_bytes();
            if !signatures.iter().any(|it| public_key.starts_with(&it.pub_key_prefix)) {
                let (pk, sig) = signer.sign(&body_bytes);
                signatures.push(services::SignaturePair {
                    pub_key_prefix: pk.to_bytes_raw(),
                    signature: Some(match pk.kind() {
                        crate::key::KeyKind::Ed25519 => {
                            services::signature_pair::Signature::Ed25519(sig)
                        }
                        crate::key::KeyKind::Ecdsa => {
                            services::signature_pair::Signature::EcdsaSecp256k1(sig)
                        }
                    }),
                });
            }
        }

        let signed_transaction = services::SignedTransaction {
            body_bytes,
            sig_map: Some(services::SignatureMap { sig_pair: signatures.clone() }),
        };
        services::Transaction {
            signed_transaction_bytes: Vec::new(),
            body: None,
            sigs: None,
            body_bytes: signed_transaction.body_bytes,
            sig_map: Some(services::SignatureMap { sig_pair: signatures.clone() }),
        }
    }
}

impl<D> Transaction<D>
where
    D: TransactionData,
{
    /// Returns the maximum allowed transaction fee if none is specified.
    ///
    /// Specifically, this default will be used in the following case:
    /// - The transaction itself (direct user input) has no `max_transaction_fee` specified, AND
    /// - The [`Client`](Client) has no `max_transaction_fee` specified.
    ///
    /// Currently this is (but not guaranteed to be) `2 ℏ` for most transaction types.
    pub fn default_max_transaction_fee(&self) -> Hbar {
        self.data().default_max_transaction_fee()
    }
}

impl<D> Transaction<D>
where
    D: TransactionExecute,
{
    /// Get the estimated transaction cost for this transaction.
    pub async fn get_cost(&self, client: &Client) -> crate::Result<Hbar> {
        let result = CostTransaction::from_transaction(self).execute(client).await;

        match result {
            Ok(response) => {
                // unexpected response from Hiero, expecting to receive an `InsufficientTxFee` but received `Ok`
                return Err(Error::TransactionPreCheckStatus {
                    cost: None,
                    status: services::ResponseCodeEnum::Ok,
                    transaction_id: Box::new(response.transaction_id),
                });
            }

            Err(Error::TransactionPreCheckStatus { status, cost: Some(cost), .. })
                if status == services::ResponseCodeEnum::InsufficientTxFee =>
            {
                return Ok(cost);
            }

            Err(error) => Err(error),
        }
    }

    /// Execute this transaction against the provided client of the Hiero network.
    pub async fn execute(&mut self, client: &Client) -> crate::Result<TransactionResponse> {
        self.execute_with_optional_timeout(client, None).await
    }

    pub(crate) async fn execute_with_optional_timeout(
        &mut self,
        client: &Client,
        timeout: Option<std::time::Duration>,
    ) -> crate::Result<TransactionResponse> {
        // it's fine to call freeze while already frozen, so, let `freeze_with` handle the freeze check.
        self.freeze_with(Some(client))?;

        if let Some(sources) = self.sources() {
            // Check if sources are "empty" (no transaction IDs and no node IDs)
            let has_transaction_ids =
                sources.chunks().any(|chunk| chunk.transaction_id().is_some());
            let has_node_ids = !sources.node_ids().is_empty();

            if has_transaction_ids || has_node_ids {
                // Sources have useful data, use them
                return self::execute::SourceTransaction::new(self, sources)
                    .execute(client, timeout)
                    .await;
            } else {
                // Sources are empty, clear them and use regular execution
                self.sources = None;
            }
        }

        if let Some(chunk_data) = self.data().maybe_chunk_data() {
            // todo: log a warning: user actually wanted `execute_all`.
            // instead of `panic`king we just pretend we were `execute_all` and
            // return the first result (*after* executing all the transactions).
            return self
                .execute_all_inner(chunk_data, client, timeout)
                .await
                .map(|mut it| it.swap_remove(0));
        }

        execute(client, self, timeout).await
    }

    // this is in *this* impl block rather than the `: TransactionExecuteChunked` impl block
    //because there's the off chance that someone calls `execute` on a Transaction that wants `execute_all`...
    async fn execute_all_inner(
        &self,
        chunk_data: &ChunkData,
        client: &Client,
        timeout_per_chunk: Option<std::time::Duration>,
    ) -> crate::Result<Vec<TransactionResponse>> {
        assert!(self.is_frozen());

        let wait_for_receipts = self.data().wait_for_receipt();

        // fixme: error with an actual error.
        #[allow(clippy::manual_assert)]
        if chunk_data.data.len() > chunk_data.max_message_len() {
            todo!("error: message too big")
        }

        let used_chunks = chunk_data.used_chunks();

        let mut responses = Vec::with_capacity(chunk_data.used_chunks());

        let initial_transaction_id = {
            let resp = execute(
                client,
                &chunked::FirstChunkView { transaction: self, total_chunks: used_chunks },
                timeout_per_chunk,
            )
            .await?;

            if wait_for_receipts {
                resp.get_receipt_query()
                    .execute_with_optional_timeout(client, timeout_per_chunk)
                    .await?;
            }

            let initial_transaction_id = resp.transaction_id;
            responses.push(resp);

            initial_transaction_id
        };

        for chunk in 1..used_chunks {
            let resp = execute(
                client,
                &chunked::ChunkView {
                    transaction: self,
                    initial_transaction_id,
                    current_chunk: chunk,
                    total_chunks: used_chunks,
                },
                timeout_per_chunk,
            )
            .await?;

            if wait_for_receipts {
                resp.get_receipt_query()
                    .execute_with_optional_timeout(client, timeout_per_chunk)
                    .await?;
            }

            responses.push(resp);
        }

        Ok(responses)
    }

    /// Execute this transaction against the provided client of the Hiero network.
    // todo:
    #[allow(clippy::missing_errors_doc)]
    pub async fn execute_with_timeout(
        &mut self,
        client: &Client,
        // fixme: be consistent with `time::Duration`? Except `tokio::time` is `std::time`, and we depend on tokio.
        timeout: std::time::Duration,
    ) -> crate::Result<TransactionResponse> {
        self.execute_with_optional_timeout(client, Some(timeout)).await
    }
}

impl<D> Transaction<D>
where
    D: TransactionExecuteChunked,
{
    /// Execute all transactions against the provided client of the Hiero network.
    pub async fn execute_all(
        &mut self,
        client: &Client,
    ) -> crate::Result<Vec<TransactionResponse>> {
        self.execute_all_with_optional_timeout(client, None).await
    }

    pub(crate) async fn execute_all_with_optional_timeout(
        &mut self,
        client: &Client,
        timeout_per_chunk: Option<std::time::Duration>,
    ) -> crate::Result<Vec<TransactionResponse>> {
        // it's fine to call freeze while already frozen, so, let `freeze_with` handle the freeze check.
        self.freeze_with(Some(client))?;

        // fixme: dedup this with `execute_with_optional_timeout`
        if let Some(sources) = self.sources() {
            // Check if sources are "empty" (no transaction IDs and no node IDs)
            let has_transaction_ids =
                sources.chunks().any(|chunk| chunk.transaction_id().is_some());
            let has_node_ids = !sources.node_ids().is_empty();

            if has_transaction_ids || has_node_ids {
                // Sources have useful data, use them
                return self::execute::SourceTransaction::new(self, sources)
                    .execute_all(client, timeout_per_chunk)
                    .await;
            } else {
                // Sources are empty, clear them and use regular execution
                self.sources = None;
            }
        }

        // sorry for the mess: this can technically infinite loop
        // (it won't, the loop condition would be dependent on chunk_data somehow being `Some` and `None` at the same time).
        let Some(chunk_data) = self.data().maybe_chunk_data() else {
            return Ok(Vec::from([self
                .execute_with_optional_timeout(client, timeout_per_chunk)
                .await?]));
        };

        self.execute_all_inner(chunk_data, client, timeout_per_chunk).await
    }
}

// these impls are on `AnyTransaction`, but they're here instead of in `any` because actually implementing them is only possible here.
impl AnyTransaction {
    /// # Examples
    /// ```
    /// # fn main() -> hiero_sdk::Result<()> {
    /// use hiero_sdk::AnyTransaction;
    /// let bytes = hex::decode(concat!(
    ///     "0a522a500a4c0a120a0c0885c8879e0610a8bdd9840312021865120218061880",
    ///     "94ebdc0322020877320c686920686173686772617068721a0a180a0a0a021802",
    ///     "108088debe010a0a0a02186510ff87debe0112000a522a500a4c0a120a0c0885",
    ///     "c8879e0610a8bdd984031202186512021807188094ebdc0322020877320c6869",
    ///     "20686173686772617068721a0a180a0a0a021802108088debe010a0a0a021865",
    ///     "10ff87debe011200"
    /// )).unwrap();
    /// let tx = AnyTransaction::from_bytes(&bytes)?;
    /// # let _ = tx;
    /// # Ok(())
    /// # }
    /// ```
    /// # Errors
    /// - [`Error::FromProtobuf`] if a valid transaction cannot be parsed from the bytes.
    #[allow(deprecated)]
    pub fn from_bytes(bytes: &[u8]) -> crate::Result<Self> {
        let list: hiero_sdk_proto::sdk::TransactionList =
            hiero_sdk_proto::sdk::TransactionList::decode(bytes).map_err(Error::from_protobuf)?;

        let list = if list.transaction_list.is_empty() {
            Vec::from([services::Transaction::decode(bytes).map_err(Error::from_protobuf)?])
        } else {
            list.transaction_list
        };

        let sources = TransactionSources::new(list)?;

        let transaction_bodies: Result<Vec<_>, _> = if !sources.signed_transactions().is_empty() {
            sources
                .signed_transactions()
                .iter()
                .map(|transaction| {
                    services::TransactionBody::decode(&*transaction.body_bytes)
                        .map_err(Error::from_protobuf)
                })
                .collect()
        } else {
            sources
                .transactions()
                .iter()
                .map(|transaction| {
                    services::TransactionBody::decode(&*transaction.body_bytes)
                        .map_err(Error::from_protobuf)
                })
                .collect()
        };

        let transaction_bodies = transaction_bodies?;
        {
            let (first, transaction_bodies) = transaction_bodies
                .split_first()
                .ok_or_else(|| Error::from_protobuf("no transactions found"))?;

            for it in transaction_bodies {
                if !pb_transaction_body_eq(first, it) {
                    return Err(Error::from_protobuf("transaction parts unexpectedly unequal"));
                }
            }
        }

        // todo: reuse work
        let transaction_data = {
            let data: Result<_, _> = sources
                .chunks()
                .map(|it| {
                    if it.transactions().first().unwrap().body_bytes.len() == 0 {
                        services::TransactionBody::decode(
                            &*it.signed_transactions().first().unwrap().body_bytes,
                        )
                    } else {
                        services::TransactionBody::decode(
                            &*it.transactions().first().unwrap().body_bytes,
                        )
                    }
                    .map_err(Error::from_protobuf)
                    .and_then(|pb| pb_getf!(pb, data))
                })
                .collect();

            data?
        };

        let mut res = Self::from_protobuf(transaction_bodies[0].clone(), transaction_data)?;

        // note: this doesn't check freeze for obvious reasons.

        let node_ids = sources.node_ids().to_vec();

        res.body.node_account_ids = if node_ids.is_empty() { None } else { Some(node_ids) };
        res.sources = Some(sources);

        Ok(res)
    }
}

/// Returns `true` if lhs == rhs other than `transaction_id` and `node_account_id`, `false` otherwise.
#[allow(deprecated)]
fn pb_transaction_body_eq(
    lhs: &services::TransactionBody,
    rhs: &services::TransactionBody,
) -> bool {
    // destructure one side to ensure we don't miss any fields.
    let services::TransactionBody {
        transaction_id: _,
        node_account_id: _,
        transaction_fee,
        transaction_valid_duration,
        generate_record,
        memo,
        data,
        max_custom_fees,
        batch_key: _,
    } = rhs;

    if &lhs.transaction_fee != transaction_fee {
        return false;
    }

    if &lhs.transaction_valid_duration != transaction_valid_duration {
        return false;
    }

    if &lhs.generate_record != generate_record {
        return false;
    }

    if &lhs.memo != memo {
        return false;
    }

    if &lhs.max_custom_fees != max_custom_fees {
        return false;
    }

    match (&lhs.data, data) {
        (None, None) => {}
        (Some(lhs), Some(rhs)) => match (lhs, rhs) {
            (
                services::transaction_body::Data::ConsensusSubmitMessage(lhs),
                services::transaction_body::Data::ConsensusSubmitMessage(rhs),
            ) => {
                let services::ConsensusSubmitMessageTransactionBody {
                    topic_id,
                    message: _,
                    chunk_info,
                } = rhs;

                if &lhs.topic_id != topic_id {
                    return false;
                }

                match (lhs.chunk_info.as_ref(), chunk_info.as_ref()) {
                    (None, None) => {}
                    (Some(lhs), Some(rhs)) => {
                        let services::ConsensusMessageChunkInfo {
                            initial_transaction_id,
                            total,
                            number: _,
                        } = rhs;

                        if &lhs.initial_transaction_id != initial_transaction_id {
                            return false;
                        }

                        if &lhs.total != total {
                            return false;
                        }
                    }
                    (Some(_), None) | (None, Some(_)) => return false,
                }
            }
            (
                services::transaction_body::Data::FileAppend(lhs),
                services::transaction_body::Data::FileAppend(rhs),
            ) => {
                let services::FileAppendTransactionBody { file_id, contents: _ } = rhs;

                if &lhs.file_id != file_id {
                    return false;
                }
            }
            (_, _) if lhs != rhs => return false,
            _ => {}
        },
        (Some(_), None) | (None, Some(_)) => return false,
    }

    true
}

// note: This impl is why this has to be a trait (overlapping impls if `D == U` with TryFrom).
impl<D, U> DowncastOwned<Transaction<U>> for Transaction<D>
where
    D: DowncastOwned<U>,
{
    fn downcast_owned(self) -> Result<Transaction<U>, Self> {
        let Self { body, signers, sources } = self;
        let TransactionBody {
            data,
            node_account_ids,
            transaction_valid_duration,
            max_transaction_fee,
            transaction_memo,
            transaction_id,
            operator,
            is_frozen,
            regenerate_transaction_id,
            custom_fee_limits,
        } = body;

        // not a `map().map_err()` because ownership.
        match data.downcast_owned() {
            Ok(data) => Ok(Transaction {
                body: TransactionBody {
                    data,
                    node_account_ids,
                    transaction_valid_duration,
                    max_transaction_fee,
                    transaction_memo,
                    transaction_id,
                    operator,
                    is_frozen,
                    regenerate_transaction_id,
                    custom_fee_limits,
                },
                signers,
                sources,
            }),

            Err(data) => Err(Self {
                body: TransactionBody {
                    data,
                    node_account_ids,
                    transaction_valid_duration,
                    max_transaction_fee,
                    transaction_memo,
                    transaction_id,
                    operator,
                    is_frozen,
                    regenerate_transaction_id,
                    custom_fee_limits,
                },
                signers,
                sources,
            }),
        }
    }
}

#[cfg(test)]
pub(crate) mod test_helpers {
    use hiero_sdk_proto::services;
    use prost::Message;
    use time::{
        Duration,
        OffsetDateTime,
    };

    use super::TransactionExecute;
    use crate::protobuf::ToProtobuf;
    use crate::{
        AccountId,
        Hbar,
        NftId,
        PrivateKey,
        TokenId,
        Transaction,
        TransactionId,
    };

    impl<D: Default> Transaction<D> {
        // todo: bikeshed name, idc.
        /// Creates a transaction with some fields set to regular values to make serialization more regular.
        ///
        /// Currently the fields set are `node_account_ids`, `transaction_id`, and `max_transaction_fee`.
        /// Additionally the transaction is signed with 1 key.
        pub(crate) fn new_for_tests() -> Self {
            let mut tx = Self::new();

            tx.node_account_ids(TEST_NODE_ACCOUNT_IDS)
                .transaction_id(TEST_TX_ID)
                .max_transaction_fee(Hbar::new(2))
                .sign(unused_private_key());

            tx
        }
    }

    #[track_caller]
    pub(crate) fn transaction_body<D: TransactionExecute>(
        tx: Transaction<D>,
    ) -> services::TransactionBody {
        // if you're thinking "ghee, that sure is a silly way to get a transaction body" you aren't wrong.
        services::TransactionBody::decode(&*tx.make_sources().unwrap().transactions()[0].body_bytes)
            .unwrap()
    }

    #[track_caller]
    pub(crate) fn transaction_bodies<D: TransactionExecute>(
        tx: Transaction<D>,
    ) -> Vec<services::TransactionBody> {
        tx.make_sources()
            .unwrap()
            .transactions()
            .iter()
            .map(|it| services::TransactionBody::decode(&*it.body_bytes).unwrap())
            .collect()
    }

    /// Checks the entire traknsaction body *other than* `data` and returns that.
    ///
    /// This is basically a boilerplate reducer, however, it failing means that [`Transaction::new_for_tests`] is probably buggy.
    pub(crate) fn check_body(body: services::TransactionBody) -> services::transaction_body::Data {
        #[allow(deprecated)]
        let services::TransactionBody {
            transaction_id,
            node_account_id,
            transaction_fee,
            transaction_valid_duration,
            generate_record,
            memo,
            data,
            max_custom_fees,
            batch_key: _,
        } = body;

        assert_eq!(transaction_id, Some(TEST_TX_ID.to_protobuf()));

        assert_eq!(transaction_fee, Hbar::new(2).to_tinybars() as u64);
        assert_eq!(transaction_valid_duration, Some(services::Duration { seconds: 120 }));
        assert_eq!(generate_record, false);
        assert_eq!(memo, "");
        assert_eq!(max_custom_fees, vec![]);
        data.unwrap()
    }

    pub(crate) fn unused_private_key() -> PrivateKey {
        "302e020100300506032b657004220420db484b828e64b2d8f12ce3c0a0e93a0b8cce7af1bb8f39c97732394482538e10".parse().unwrap()
    }

    pub(crate) const TEST_TOKEN_ID: TokenId = TokenId::new(1, 2, 3);

    pub(crate) const TEST_TOKEN_IDS: [TokenId; 3] =
        [TokenId::new(1, 2, 3), TokenId::new(2, 3, 4), TokenId::new(3, 4, 5)];

    pub(crate) const TEST_NFT_IDS: [NftId; 3] = [
        NftId { token_id: TokenId::new(4, 2, 3), serial: 1 },
        NftId { token_id: TokenId::new(4, 2, 4), serial: 2 },
        NftId { token_id: TokenId::new(4, 2, 5), serial: 3 },
    ];

    pub(crate) const TEST_ACCOUNT_ID: AccountId = AccountId::new(0, 0, 5006);

    pub(crate) const TEST_NODE_ACCOUNT_IDS: [AccountId; 2] =
        [AccountId::new(0, 0, 5005), AccountId::new(0, 0, 5006)];

    pub(crate) const TEST_TX_ID: TransactionId = TransactionId {
        account_id: TEST_ACCOUNT_ID,
        valid_start: VALID_START,
        nonce: None,
        scheduled: false,
    };

    pub(crate) const VALID_START: OffsetDateTime =
        OffsetDateTime::UNIX_EPOCH.saturating_add(Duration::seconds(1554158542));
}