pezkuwi-subxt 0.44.0

// Copyright 2019-2025 Parity Technologies (UK) Ltd.
// This file is dual-licensed as Apache-2.0 or GPL-3.0.
// see LICENSE for license details.

use crate::{
	backend::{BackendExt, BlockRef, TransactionStatus},
	client::{OfflineClientT, OnlineClientT},
	config::{Config, ExtrinsicParams, HashFor, Header},
	error::{ExtrinsicError, TransactionStatusError},
	tx::{Payload, Signer as SignerT, TxProgress},
	utils::PhantomDataSendSync,
};
use codec::{Compact, Decode, Encode};
use derive_where::derive_where;
use futures::future::{try_join, TryFutureExt};
use pezkuwi_subxt_core::tx::TransactionVersion;

/// A client for working with transactions.
#[derive_where(Clone; Client)]
pub struct TxClient<T: Config, Client> {
	client: Client,
	_marker: PhantomDataSendSync<T>,
}

impl<T: Config, Client> TxClient<T, Client> {
	/// Create a new [`TxClient`]
	pub fn new(client: Client) -> Self {
		Self { client, _marker: PhantomDataSendSync::new() }
	}
}

impl<T: Config, C: OfflineClientT<T>> TxClient<T, C> {
	/// Run the validation logic against some transaction you'd like to submit. Returns `Ok(())`
	/// if the call is valid (or if it's not possible to check since the call has no validation
	/// hash). Return an error if the call was not valid or something went wrong trying to validate
	/// it (ie the pallet or call in question do not exist at all).
	pub fn validate<Call>(&self, call: &Call) -> Result<(), ExtrinsicError>
	where
		Call: Payload,
	{
		pezkuwi_subxt_core::tx::validate(call, &self.client.metadata()).map_err(Into::into)
	}

	/// Return the SCALE encoded bytes representing the call data of the transaction.
	pub fn call_data<Call>(&self, call: &Call) -> Result<Vec<u8>, ExtrinsicError>
	where
		Call: Payload,
	{
		pezkuwi_subxt_core::tx::call_data(call, &self.client.metadata()).map_err(Into::into)
	}

	/// Creates an unsigned transaction without submitting it. Depending on the metadata, we might
	/// end up constructing either a v4 or v5 transaction. See [`Self::create_v4_unsigned`] or
	/// [`Self::create_v5_bare`] if you'd like to explicitly create an unsigned transaction of a
	/// certain version.
	pub fn create_unsigned<Call>(
		&self,
		call: &Call,
	) -> Result<SubmittableTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let metadata = self.client.metadata();
		let tx = match pezkuwi_subxt_core::tx::suggested_version(&metadata)? {
			TransactionVersion::V4 => pezkuwi_subxt_core::tx::create_v4_unsigned(call, &metadata),
			TransactionVersion::V5 => pezkuwi_subxt_core::tx::create_v5_bare(call, &metadata),
		}?;

		Ok(SubmittableTransaction { client: self.client.clone(), inner: tx })
	}

	/// Creates a v4 unsigned (no signature or transaction extensions) transaction without
	/// submitting it.
	///
	/// Prefer [`Self::create_unsigned()`] if you don't know which version to create; this will pick
	/// the most suitable one for the given chain.
	pub fn create_v4_unsigned<Call>(
		&self,
		call: &Call,
	) -> Result<SubmittableTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let metadata = self.client.metadata();
		let tx = pezkuwi_subxt_core::tx::create_v4_unsigned(call, &metadata)?;

		Ok(SubmittableTransaction { client: self.client.clone(), inner: tx })
	}

	/// Creates a v5 "bare" (no signature or transaction extensions) transaction without submitting
	/// it.
	///
	/// Prefer [`Self::create_unsigned()`] if you don't know which version to create; this will pick
	/// the most suitable one for the given chain.
	pub fn create_v5_bare<Call>(
		&self,
		call: &Call,
	) -> Result<SubmittableTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let metadata = self.client.metadata();
		let tx = pezkuwi_subxt_core::tx::create_v5_bare(call, &metadata)?;

		Ok(SubmittableTransaction { client: self.client.clone(), inner: tx })
	}

	/// Create a partial transaction. Depending on the metadata, we might end up constructing either
	/// a v4 or v5 transaction. See [`pezkuwi_subxt_core::tx`] if you'd like to manually pick the
	/// version to construct
	///
	/// Note: if not provided, the default account nonce will be set to 0 and the default mortality
	/// will be _immortal_. This is because this method runs offline, and so is unable to fetch the
	/// data needed for more appropriate values.
	pub fn create_partial_offline<Call>(
		&self,
		call: &Call,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let metadata = self.client.metadata();
		let tx = match pezkuwi_subxt_core::tx::suggested_version(&metadata)? {
			TransactionVersion::V4 => {
				PartialTransactionInner::V4(pezkuwi_subxt_core::tx::create_v4_signed(
					call,
					&self.client.client_state(),
					params,
				)?)
			},
			TransactionVersion::V5 => {
				PartialTransactionInner::V5(pezkuwi_subxt_core::tx::create_v5_general(
					call,
					&self.client.client_state(),
					params,
				)?)
			},
		};

		Ok(PartialTransaction { client: self.client.clone(), inner: tx })
	}

	/// Create a v4 partial transaction, ready to sign.
	///
	/// Note: if not provided, the default account nonce will be set to 0 and the default mortality
	/// will be _immortal_. This is because this method runs offline, and so is unable to fetch the
	/// data needed for more appropriate values.
	///
	/// Prefer [`Self::create_partial_offline()`] if you don't know which version to create; this
	/// will pick the most suitable one for the given chain.
	pub fn create_v4_partial_offline<Call>(
		&self,
		call: &Call,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let tx = PartialTransactionInner::V4(pezkuwi_subxt_core::tx::create_v4_signed(
			call,
			&self.client.client_state(),
			params,
		)?);

		Ok(PartialTransaction { client: self.client.clone(), inner: tx })
	}

	/// Create a v5 partial transaction, ready to sign.
	///
	/// Note: if not provided, the default account nonce will be set to 0 and the default mortality
	/// will be _immortal_. This is because this method runs offline, and so is unable to fetch the
	/// data needed for more appropriate values.
	///
	/// Prefer [`Self::create_partial_offline()`] if you don't know which version to create; this
	/// will pick the most suitable one for the given chain.
	pub fn create_v5_partial_offline<Call>(
		&self,
		call: &Call,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		let tx = PartialTransactionInner::V5(pezkuwi_subxt_core::tx::create_v5_general(
			call,
			&self.client.client_state(),
			params,
		)?);

		Ok(PartialTransaction { client: self.client.clone(), inner: tx })
	}
}

impl<T, C> TxClient<T, C>
where
	T: Config,
	C: OnlineClientT<T>,
{
	/// Get the account nonce for a given account ID.
	pub async fn account_nonce(&self, account_id: &T::AccountId) -> Result<u64, ExtrinsicError> {
		let block_ref = self
			.client
			.backend()
			.latest_finalized_block_ref()
			.await
			.map_err(ExtrinsicError::CannotGetLatestFinalizedBlock)?;

		crate::blocks::get_account_nonce(&self.client, account_id, block_ref.hash())
			.await
			.map_err(|e| ExtrinsicError::AccountNonceError {
				block_hash: block_ref.hash().into(),
				account_id: account_id.encode().into(),
				reason: e,
			})
	}

	/// Creates a partial transaction, without submitting it. This can then be signed and submitted.
	pub async fn create_partial<Call>(
		&self,
		call: &Call,
		account_id: &T::AccountId,
		mut params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		inject_account_nonce_and_block(&self.client, account_id, &mut params).await?;
		self.create_partial_offline(call, params)
	}

	/// Creates a partial V4 transaction, without submitting it. This can then be signed and
	/// submitted.
	///
	/// Prefer [`Self::create_partial()`] if you don't know which version to create; this will pick
	/// the most suitable one for the given chain.
	pub async fn create_v4_partial<Call>(
		&self,
		call: &Call,
		account_id: &T::AccountId,
		mut params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		inject_account_nonce_and_block(&self.client, account_id, &mut params).await?;
		self.create_v4_partial_offline(call, params)
	}

	/// Creates a partial V5 transaction, without submitting it. This can then be signed and
	/// submitted.
	///
	/// Prefer [`Self::create_partial()`] if you don't know which version to create; this will pick
	/// the most suitable one for the given chain.
	pub async fn create_v5_partial<Call>(
		&self,
		call: &Call,
		account_id: &T::AccountId,
		mut params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<PartialTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
	{
		inject_account_nonce_and_block(&self.client, account_id, &mut params).await?;
		self.create_v5_partial_offline(call, params)
	}

	/// Creates a signed transaction, without submitting it.
	pub async fn create_signed<Call, Signer>(
		&mut self,
		call: &Call,
		signer: &Signer,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<SubmittableTransaction<T, C>, ExtrinsicError>
	where
		Call: Payload,
		Signer: SignerT<T>,
	{
		let mut partial = self.create_partial(call, &signer.account_id(), params).await?;

		Ok(partial.sign(signer))
	}

	/// Creates and signs an transaction and submits it to the chain. Passes default parameters
	/// to construct the "signed extra" and "additional" payloads needed by the transaction.
	///
	/// Returns a [`TxProgress`], which can be used to track the status of the transaction
	/// and obtain details about it, once it has made it into a block.
	pub async fn sign_and_submit_then_watch_default<Call, Signer>(
		&mut self,
		call: &Call,
		signer: &Signer,
	) -> Result<TxProgress<T, C>, ExtrinsicError>
	where
		Call: Payload,
		Signer: SignerT<T>,
		<T::ExtrinsicParams as ExtrinsicParams<T>>::Params: DefaultParams,
	{
		self.sign_and_submit_then_watch(call, signer, DefaultParams::default_params())
			.await
	}

	/// Creates and signs an transaction and submits it to the chain.
	///
	/// Returns a [`TxProgress`], which can be used to track the status of the transaction
	/// and obtain details about it, once it has made it into a block.
	pub async fn sign_and_submit_then_watch<Call, Signer>(
		&mut self,
		call: &Call,
		signer: &Signer,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<TxProgress<T, C>, ExtrinsicError>
	where
		Call: Payload,
		Signer: SignerT<T>,
	{
		self.create_signed(call, signer, params).await?.submit_and_watch().await
	}

	/// Creates and signs an transaction and submits to the chain for block inclusion. Passes
	/// default parameters to construct the "signed extra" and "additional" payloads needed
	/// by the transaction.
	///
	/// Returns `Ok` with the transaction hash if it is valid transaction.
	///
	/// # Note
	///
	/// Success does not mean the transaction has been included in the block, just that it is valid
	/// and has been included in the transaction pool.
	pub async fn sign_and_submit_default<Call, Signer>(
		&mut self,
		call: &Call,
		signer: &Signer,
	) -> Result<HashFor<T>, ExtrinsicError>
	where
		Call: Payload,
		Signer: SignerT<T>,
		<T::ExtrinsicParams as ExtrinsicParams<T>>::Params: DefaultParams,
	{
		self.sign_and_submit(call, signer, DefaultParams::default_params()).await
	}

	/// Creates and signs an transaction and submits to the chain for block inclusion.
	///
	/// Returns `Ok` with the transaction hash if it is valid transaction.
	///
	/// # Note
	///
	/// Success does not mean the transaction has been included in the block, just that it is valid
	/// and has been included in the transaction pool.
	pub async fn sign_and_submit<Call, Signer>(
		&mut self,
		call: &Call,
		signer: &Signer,
		params: <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
	) -> Result<HashFor<T>, ExtrinsicError>
	where
		Call: Payload,
		Signer: SignerT<T>,
	{
		self.create_signed(call, signer, params).await?.submit().await
	}
}

/// This payload contains the information needed to produce an transaction.
pub struct PartialTransaction<T: Config, C> {
	client: C,
	inner: PartialTransactionInner<T>,
}

enum PartialTransactionInner<T: Config> {
	V4(pezkuwi_subxt_core::tx::PartialTransactionV4<T>),
	V5(pezkuwi_subxt_core::tx::PartialTransactionV5<T>),
}

impl<T, C> PartialTransaction<T, C>
where
	T: Config,
	C: OfflineClientT<T>,
{
	/// Return the signer payload for this transaction. These are the bytes that must
	/// be signed in order to produce a valid signature for the transaction.
	pub fn signer_payload(&self) -> Vec<u8> {
		match &self.inner {
			PartialTransactionInner::V4(tx) => tx.signer_payload(),
			PartialTransactionInner::V5(tx) => tx.signer_payload().to_vec(),
		}
	}

	/// Return the bytes representing the call data for this partially constructed
	/// transaction.
	pub fn call_data(&self) -> &[u8] {
		match &self.inner {
			PartialTransactionInner::V4(tx) => tx.call_data(),
			PartialTransactionInner::V5(tx) => tx.call_data(),
		}
	}

	/// Convert this [`PartialTransaction`] into a [`SubmittableTransaction`], ready to submit.
	/// The provided `signer` is responsible for providing the "from" address for the transaction,
	/// as well as providing a signature to attach to it.
	pub fn sign<Signer>(&mut self, signer: &Signer) -> SubmittableTransaction<T, C>
	where
		Signer: SignerT<T>,
	{
		let tx = match &mut self.inner {
			PartialTransactionInner::V4(tx) => tx.sign(signer),
			PartialTransactionInner::V5(tx) => tx.sign(signer),
		};

		SubmittableTransaction { client: self.client.clone(), inner: tx }
	}

	/// Convert this [`PartialTransaction`] into a [`SubmittableTransaction`], ready to submit.
	/// An address, and something representing a signature that can be SCALE encoded, are both
	/// needed in order to construct it. If you have a `Signer` to hand, you can use
	/// [`PartialTransaction::sign()`] instead.
	pub fn sign_with_account_and_signature(
		&mut self,
		account_id: &T::AccountId,
		signature: &T::Signature,
	) -> SubmittableTransaction<T, C> {
		let tx = match &mut self.inner {
			PartialTransactionInner::V4(tx) => {
				tx.sign_with_account_and_signature(account_id.clone(), signature)
			},
			PartialTransactionInner::V5(tx) => {
				tx.sign_with_account_and_signature(account_id, signature)
			},
		};

		SubmittableTransaction { client: self.client.clone(), inner: tx }
	}
}

/// This represents an transaction that has been signed and is ready to submit.
pub struct SubmittableTransaction<T, C> {
	client: C,
	inner: pezkuwi_subxt_core::tx::Transaction<T>,
}

impl<T, C> SubmittableTransaction<T, C>
where
	T: Config,
	C: OfflineClientT<T>,
{
	/// Create a [`SubmittableTransaction`] from some already-signed and prepared
	/// transaction bytes, and some client (anything implementing [`OfflineClientT`]
	/// or [`OnlineClientT`]).
	///
	/// Prefer to use [`TxClient`] to create and sign transactions. This is simply
	/// exposed in case you want to skip this process and submit something you've
	/// already created.
	pub fn from_bytes(client: C, tx_bytes: Vec<u8>) -> Self {
		Self { client, inner: pezkuwi_subxt_core::tx::Transaction::from_bytes(tx_bytes) }
	}

	/// Calculate and return the hash of the transaction, based on the configured hasher.
	pub fn hash(&self) -> HashFor<T> {
		self.inner.hash_with(self.client.hasher())
	}

	/// Returns the SCALE encoded transaction bytes.
	pub fn encoded(&self) -> &[u8] {
		self.inner.encoded()
	}

	/// Consumes [`SubmittableTransaction`] and returns the SCALE encoded
	/// transaction bytes.
	pub fn into_encoded(self) -> Vec<u8> {
		self.inner.into_encoded()
	}
}

impl<T, C> SubmittableTransaction<T, C>
where
	T: Config,
	C: OnlineClientT<T>,
{
	/// Submits the transaction to the chain.
	///
	/// Returns a [`TxProgress`], which can be used to track the status of the transaction
	/// and obtain details about it, once it has made it into a block.
	pub async fn submit_and_watch(&self) -> Result<TxProgress<T, C>, ExtrinsicError> {
		// Get a hash of the transaction (we'll need this later).
		let ext_hash = self.hash();

		// Submit and watch for transaction progress.
		let sub = self
			.client
			.backend()
			.submit_transaction(self.encoded())
			.await
			.map_err(ExtrinsicError::ErrorSubmittingTransaction)?;

		Ok(TxProgress::new(sub, self.client.clone(), ext_hash))
	}

	/// Submits the transaction to the chain for block inclusion.
	///
	/// It's usually better to call `submit_and_watch` to get an idea of the progress of the
	/// submission and whether it's eventually successful or not. This call does not guarantee
	/// success, and is just sending the transaction to the chain.
	pub async fn submit(&self) -> Result<HashFor<T>, ExtrinsicError> {
		let ext_hash = self.hash();
		let mut sub = self
			.client
			.backend()
			.submit_transaction(self.encoded())
			.await
			.map_err(ExtrinsicError::ErrorSubmittingTransaction)?;

		// If we get a bad status or error back straight away then error, else return the hash.
		match sub.next().await {
			Some(Ok(status)) => match status {
				TransactionStatus::Validated
				| TransactionStatus::Broadcasted
				| TransactionStatus::InBestBlock { .. }
				| TransactionStatus::NoLongerInBestBlock
				| TransactionStatus::InFinalizedBlock { .. } => Ok(ext_hash),
				TransactionStatus::Error { message } => Err(
					ExtrinsicError::TransactionStatusError(TransactionStatusError::Error(message)),
				),
				TransactionStatus::Invalid { message } => {
					Err(ExtrinsicError::TransactionStatusError(TransactionStatusError::Invalid(
						message,
					)))
				},
				TransactionStatus::Dropped { message } => {
					Err(ExtrinsicError::TransactionStatusError(TransactionStatusError::Dropped(
						message,
					)))
				},
			},
			Some(Err(e)) => Err(ExtrinsicError::TransactionStatusStreamError(e)),
			None => Err(ExtrinsicError::UnexpectedEndOfTransactionStatusStream),
		}
	}

	/// Validate a transaction by submitting it to the relevant Runtime API. A transaction that is
	/// valid can be added to a block, but may still end up in an error state.
	///
	/// Returns `Ok` with a [`ValidationResult`], which is the result of attempting to dry run the
	/// transaction.
	pub async fn validate(&self) -> Result<ValidationResult, ExtrinsicError> {
		let latest_block_ref = self
			.client
			.backend()
			.latest_finalized_block_ref()
			.await
			.map_err(ExtrinsicError::CannotGetLatestFinalizedBlock)?;
		self.validate_at(latest_block_ref).await
	}

	/// Validate a transaction by submitting it to the relevant Runtime API. A transaction that is
	/// valid can be added to a block, but may still end up in an error state.
	///
	/// Returns `Ok` with a [`ValidationResult`], which is the result of attempting to dry run the
	/// transaction.
	pub async fn validate_at(
		&self,
		at: impl Into<BlockRef<HashFor<T>>>,
	) -> Result<ValidationResult, ExtrinsicError> {
		let block_hash = at.into().hash();

		// Approach taken from https://github.com/pezkuwichain/json-rpc-interface-spec/issues/55.
		let mut params = Vec::with_capacity(8 + self.encoded().len() + 8);
		2u8.encode_to(&mut params);
		params.extend(self.encoded().iter());
		block_hash.encode_to(&mut params);

		let res: Vec<u8> = self
			.client
			.backend()
			.call("TaggedTransactionQueue_validate_transaction", Some(&params), block_hash)
			.await
			.map_err(ExtrinsicError::CannotGetValidationInfo)?;

		ValidationResult::try_from_bytes(res)
	}

	/// This returns an estimate for what the transaction is expected to cost to execute, less any
	/// tips. The actual amount paid can vary from block to block based on node traffic and other
	/// factors.
	pub async fn partial_fee_estimate(&self) -> Result<u128, ExtrinsicError> {
		let mut params = self.encoded().to_vec();
		(self.encoded().len() as u32).encode_to(&mut params);
		let latest_block_ref = self
			.client
			.backend()
			.latest_finalized_block_ref()
			.await
			.map_err(ExtrinsicError::CannotGetLatestFinalizedBlock)?;

		// destructuring RuntimeDispatchInfo, see type information <https://paritytech.github.io/substrate/master/pallet_transaction_payment_rpc_runtime_api/struct.RuntimeDispatchInfo.html>
		// data layout: {weight_ref_time: Compact<u64>, weight_proof_size: Compact<u64>, class: u8,
		// partial_fee: u128}
		let (_, _, _, partial_fee) = self
			.client
			.backend()
			.call_decoding::<(Compact<u64>, Compact<u64>, u8, u128)>(
				"TransactionPaymentApi_query_info",
				Some(&params),
				latest_block_ref.hash(),
			)
			.await
			.map_err(ExtrinsicError::CannotGetFeeInfo)?;

		Ok(partial_fee)
	}
}

/// Fetch the latest block header and account nonce from the backend and use them to refine
/// [`ExtrinsicParams::Params`].
async fn inject_account_nonce_and_block<T: Config, Client: OnlineClientT<T>>(
	client: &Client,
	account_id: &T::AccountId,
	params: &mut <T::ExtrinsicParams as ExtrinsicParams<T>>::Params,
) -> Result<(), ExtrinsicError> {
	use pezkuwi_subxt_core::config::transaction_extensions::Params;

	let block_ref = client
		.backend()
		.latest_finalized_block_ref()
		.await
		.map_err(ExtrinsicError::CannotGetLatestFinalizedBlock)?;

	let (block_header, account_nonce) = try_join(
		client
			.backend()
			.block_header(block_ref.hash())
			.map_err(ExtrinsicError::CannotGetLatestFinalizedBlock),
		crate::blocks::get_account_nonce(client, account_id, block_ref.hash()).map_err(|e| {
			ExtrinsicError::AccountNonceError {
				block_hash: block_ref.hash().into(),
				account_id: account_id.encode().into(),
				reason: e,
			}
		}),
	)
	.await?;

	let block_header = block_header.ok_or_else(|| ExtrinsicError::CannotFindBlockHeader {
		block_hash: block_ref.hash().into(),
	})?;

	params.inject_account_nonce(account_nonce);
	params.inject_block(block_header.number().into(), block_ref.hash());

	Ok(())
}

impl ValidationResult {
	#[allow(clippy::get_first)]
	fn try_from_bytes(bytes: Vec<u8>) -> Result<ValidationResult, ExtrinsicError> {
		// TaggedTransactionQueue_validate_transaction returns this:
		// https://github.com/pezkuwichain/bizinikiwi/blob/0cdf7029017b70b7c83c21a4dc0aa1020e7914f6/primitives/runtime/src/transaction_validity.rs#L210
		// We copy some of the inner types and put the three states (valid, invalid, unknown) into
		// one enum, because from our perspective, the call was successful regardless.
		if bytes.get(0) == Some(&0) {
			// ok: valid. Decode but, for now we discard most of the information
			let res = TransactionValid::decode(&mut &bytes[1..])
				.map_err(ExtrinsicError::CannotDecodeValidationResult)?;
			Ok(ValidationResult::Valid(res))
		} else if bytes.get(0) == Some(&1) && bytes.get(1) == Some(&0) {
			// error: invalid
			let res = TransactionInvalid::decode(&mut &bytes[2..])
				.map_err(ExtrinsicError::CannotDecodeValidationResult)?;
			Ok(ValidationResult::Invalid(res))
		} else if bytes.get(0) == Some(&1) && bytes.get(1) == Some(&1) {
			// error: unknown
			let res = TransactionUnknown::decode(&mut &bytes[2..])
				.map_err(ExtrinsicError::CannotDecodeValidationResult)?;
			Ok(ValidationResult::Unknown(res))
		} else {
			// unable to decode the bytes; they aren't what we expect.
			Err(ExtrinsicError::UnexpectedValidationResultBytes(bytes))
		}
	}
}

/// The result of performing [`SubmittableTransaction::validate()`].
#[derive(Clone, Debug, PartialEq)]
pub enum ValidationResult {
	/// The transaction is valid
	Valid(TransactionValid),
	/// The transaction is invalid
	Invalid(TransactionInvalid),
	/// Unable to validate the transaction
	Unknown(TransactionUnknown),
}

impl ValidationResult {
	/// Is the transaction valid.
	pub fn is_valid(&self) -> bool {
		matches!(self, ValidationResult::Valid(_))
	}
}

/// Transaction is valid; here is some more information about it.
#[derive(Decode, Clone, Debug, PartialEq)]
pub struct TransactionValid {
	/// Priority of the transaction.
	///
	/// Priority determines the ordering of two transactions that have all
	/// their dependencies (required tags) satisfied.
	pub priority: u64,
	/// Transaction dependencies
	///
	/// A non-empty list signifies that some other transactions which provide
	/// given tags are required to be included before that one.
	pub requires: Vec<Vec<u8>>,
	/// Provided tags
	///
	/// A list of tags this transaction provides. Successfully importing the transaction
	/// will enable other transactions that depend on (require) those tags to be included as well.
	/// Provided and required tags allow Bizinikiwi to build a dependency graph of transactions
	/// and import them in the right (linear) order.
	pub provides: Vec<Vec<u8>>,
	/// Transaction longevity
	///
	/// Longevity describes minimum number of blocks the validity is correct.
	/// After this period transaction should be removed from the pool or revalidated.
	pub longevity: u64,
	/// A flag indicating if the transaction should be propagated to other peers.
	///
	/// By setting `false` here the transaction will still be considered for
	/// including in blocks that are authored on the current node, but will
	/// never be sent to other peers.
	pub propagate: bool,
}

/// The runtime was unable to validate the transaction.
#[derive(Decode, Clone, Debug, PartialEq)]
pub enum TransactionUnknown {
	/// Could not lookup some information that is required to validate the transaction.
	CannotLookup,
	/// No validator found for the given unsigned transaction.
	NoUnsignedValidator,
	/// Any other custom unknown validity that is not covered by this enum.
	Custom(u8),
}

/// The transaction is invalid.
#[derive(Decode, Clone, Debug, PartialEq)]
pub enum TransactionInvalid {
	/// The call of the transaction is not expected.
	Call,
	/// General error to do with the inability to pay some fees (e.g. account balance too low).
	Payment,
	/// General error to do with the transaction not yet being valid (e.g. nonce too high).
	Future,
	/// General error to do with the transaction being outdated (e.g. nonce too low).
	Stale,
	/// General error to do with the transaction's proofs (e.g. signature).
	///
	/// # Possible causes
	///
	/// When using a signed extension that provides additional data for signing, it is required
	/// that the signing and the verifying side use the same additional data. Additional
	/// data will only be used to generate the signature, but will not be part of the transaction
	/// itself. As the verifying side does not know which additional data was used while signing
	/// it will only be able to assume a bad signature and cannot express a more meaningful error.
	BadProof,
	/// The transaction birth block is ancient.
	///
	/// # Possible causes
	///
	/// For `FRAME`-based runtimes this would be caused by `current block number`
	/// - Era::birth block number > BlockHashCount`. (e.g. in Pezkuwi `BlockHashCount` = 2400, so a
	///   transaction with birth block number 1337 would be valid up until block number 1337 + 2400,
	///   after which point the transaction would be considered to have an ancient birth block.)
	AncientBirthBlock,
	/// The transaction would exhaust the resources of current block.
	///
	/// The transaction might be valid, but there are not enough resources
	/// left in the current block.
	ExhaustsResources,
	/// Any other custom invalid validity that is not covered by this enum.
	Custom(u8),
	/// An transaction with a Mandatory dispatch resulted in Error. This is indicative of either a
	/// malicious validator or a buggy `provide_inherent`. In any case, it can result in
	/// dangerously overweight blocks and therefore if found, invalidates the block.
	BadMandatory,
	/// An transaction with a mandatory dispatch tried to be validated.
	/// This is invalid; only inherent transactions are allowed to have mandatory dispatches.
	MandatoryValidation,
	/// The sending address is disabled or known to be invalid.
	BadSigner,
}

/// This trait is used to create default values for extrinsic params. We use this instead of
/// [`Default`] because we want to be able to support params which are tuples of more than 12
/// entries (which is the maximum tuple size Rust currently implements [`Default`] for on tuples),
/// given that we aren't far off having more than 12 transaction extensions already.
///
/// If you have params which are _not_ a tuple and which you'd like to be instantiated automatically
/// when calling [`TxClient::sign_and_submit_default()`] or
/// [`TxClient::sign_and_submit_then_watch_default()`], then you'll need to implement this trait for
/// them.
pub trait DefaultParams: Sized {
	/// Instantiate a default instance of the parameters.
	fn default_params() -> Self;
}

impl<const N: usize, P: Default> DefaultParams for [P; N] {
	fn default_params() -> Self {
		core::array::from_fn(|_| P::default())
	}
}

macro_rules! impl_default_params_for_tuple {
    ($($ident:ident),+) => {
        impl <$($ident : Default),+> DefaultParams for ($($ident,)+){
            fn default_params() -> Self {
                (
                    $($ident::default(),)+
                )
            }
        }
    }
}

#[rustfmt::skip]
const _: () = {
    impl_default_params_for_tuple!(A);
    impl_default_params_for_tuple!(A, B);
    impl_default_params_for_tuple!(A, B, C);
    impl_default_params_for_tuple!(A, B, C, D);
    impl_default_params_for_tuple!(A, B, C, D, E);
    impl_default_params_for_tuple!(A, B, C, D, E, F);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y);
    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z);
};

#[cfg(test)]
mod test {
	use super::*;

	#[test]
	fn transaction_validity_decoding_empty_bytes() {
		// No panic should occur decoding empty bytes.
		let decoded = ValidationResult::try_from_bytes(vec![]);
		assert!(decoded.is_err())
	}

	#[test]
	fn transaction_validity_decoding_is_ok() {
		use pezsp_runtime::{
			transaction_validity as sp, transaction_validity::TransactionValidity as T,
		};

		let pairs = vec![
			(
				T::Ok(sp::ValidTransaction { ..Default::default() }),
				ValidationResult::Valid(TransactionValid {
					// By default, tx is immortal
					longevity: u64::MAX,
					// Default is true
					propagate: true,
					priority: 0,
					provides: vec![],
					requires: vec![],
				}),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::BadProof)),
				ValidationResult::Invalid(TransactionInvalid::BadProof),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::Call)),
				ValidationResult::Invalid(TransactionInvalid::Call),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::Payment)),
				ValidationResult::Invalid(TransactionInvalid::Payment),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::Future)),
				ValidationResult::Invalid(TransactionInvalid::Future),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::Stale)),
				ValidationResult::Invalid(TransactionInvalid::Stale),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(
					sp::InvalidTransaction::AncientBirthBlock,
				)),
				ValidationResult::Invalid(TransactionInvalid::AncientBirthBlock),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(
					sp::InvalidTransaction::ExhaustsResources,
				)),
				ValidationResult::Invalid(TransactionInvalid::ExhaustsResources),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::BadMandatory)),
				ValidationResult::Invalid(TransactionInvalid::BadMandatory),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(
					sp::InvalidTransaction::MandatoryValidation,
				)),
				ValidationResult::Invalid(TransactionInvalid::MandatoryValidation),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::BadSigner)),
				ValidationResult::Invalid(TransactionInvalid::BadSigner),
			),
			(
				T::Err(sp::TransactionValidityError::Invalid(sp::InvalidTransaction::Custom(123))),
				ValidationResult::Invalid(TransactionInvalid::Custom(123)),
			),
			(
				T::Err(sp::TransactionValidityError::Unknown(sp::UnknownTransaction::CannotLookup)),
				ValidationResult::Unknown(TransactionUnknown::CannotLookup),
			),
			(
				T::Err(sp::TransactionValidityError::Unknown(
					sp::UnknownTransaction::NoUnsignedValidator,
				)),
				ValidationResult::Unknown(TransactionUnknown::NoUnsignedValidator),
			),
			(
				T::Err(sp::TransactionValidityError::Unknown(sp::UnknownTransaction::Custom(123))),
				ValidationResult::Unknown(TransactionUnknown::Custom(123)),
			),
		];

		for (sp, validation_result) in pairs {
			let encoded = sp.encode();
			let decoded = ValidationResult::try_from_bytes(encoded).expect("should decode OK");
			assert_eq!(decoded, validation_result);
		}
	}
}