miden_protocol/transaction/

tx_args.rs

use alloc::collections::BTreeMap;
use alloc::string::{String, ToString};
use alloc::sync::Arc;
use alloc::vec::Vec;
use core::fmt::Display;

use miden_core::mast::MastNodeExt;
use miden_crypto::merkle::InnerNodeInfo;
use miden_crypto_derive::WordWrapper;
use miden_mast_package::Package;
use miden_mast_package::debug_info::PackageDebugInfo;
use miden_processor::LoadedMastForest;

use super::{Felt, Hasher, Word};
use crate::account::auth::{PublicKeyCommitment, Signature};
use crate::assembly::Path;
use crate::errors::TransactionScriptError;
use crate::note::{NoteId, NoteRecipient};
use crate::package::{loaded_mast_forest, package_debug_info};
use crate::utils::create_external_node_forest;
use crate::utils::serde::{
    ByteReader,
    ByteWriter,
    Deserializable,
    DeserializationError,
    Serializable,
};
use crate::vm::{AdviceInputs, AdviceMap};
use crate::{EMPTY_WORD, MastForest, MastNodeId};

// TRANSACTION ARGUMENTS
// ================================================================================================

/// Optional transaction arguments.
///
/// - Transaction script: a program that is executed in a transaction after all input notes scripts
///   have been executed.
/// - Transaction script arguments: a [`Word`], which will be pushed to the operand stack before the
///   transaction script execution. If these arguments are not specified, the [`EMPTY_WORD`] would
///   be used as a default value. If the [AdviceInputs] are propagated with some user defined map
///   entries, this script arguments word could be used as a key to access the corresponding value.
/// - Note arguments: data put onto the stack right before a note script is executed. These are
///   different from note storage, as the user executing the transaction can specify arbitrary note
///   args.
/// - Advice inputs: provides data needed by the runtime, like the details of public output notes.
/// - Foreign account inputs: provides foreign account data that will be used during the foreign
///   procedure invocation (FPI).
/// - Auth arguments: data put onto the stack right before authentication procedure execution. If
///   this argument is not specified, the [`EMPTY_WORD`] would be used as a default value. If the
///   [AdviceInputs] are propagated with some user defined map entries, this argument could be used
///   as a key to access the corresponding value.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct TransactionArgs {
    tx_script: Option<TransactionScript>,
    tx_script_args: Word,
    note_args: BTreeMap<NoteId, Word>,
    advice_inputs: AdviceInputs,
    auth_args: Word,
}

impl TransactionArgs {
    // CONSTRUCTORS
    // --------------------------------------------------------------------------------------------

    /// Returns new [TransactionArgs] instantiated with the provided transaction script, advice
    /// map and foreign account inputs.
    pub fn new(advice_map: AdviceMap) -> Self {
        let advice_inputs = AdviceInputs { map: advice_map, ..Default::default() };

        Self {
            tx_script: None,
            tx_script_args: EMPTY_WORD,
            note_args: Default::default(),
            advice_inputs,
            auth_args: EMPTY_WORD,
        }
    }

    /// Returns new [TransactionArgs] instantiated with the provided transaction script.
    ///
    /// If the transaction script is already set, it will be overwritten with the newly provided
    /// one.
    #[must_use]
    pub fn with_tx_script(mut self, tx_script: TransactionScript) -> Self {
        self.tx_script = Some(tx_script);
        self
    }

    /// Returns new [TransactionArgs] instantiated with the provided transaction script and its
    /// arguments.
    ///
    /// If the transaction script and arguments are already set, they will be overwritten with the
    /// newly provided ones.
    #[must_use]
    pub fn with_tx_script_and_args(
        mut self,
        tx_script: TransactionScript,
        tx_script_args: Word,
    ) -> Self {
        self.tx_script = Some(tx_script);
        self.tx_script_args = tx_script_args;
        self
    }

    /// Returns new [TransactionArgs] instantiated with the provided note arguments.
    ///
    /// If the note arguments were already set, they will be overwritten with the newly provided
    /// ones.
    #[must_use]
    pub fn with_note_args(mut self, note_args: BTreeMap<NoteId, Word>) -> Self {
        self.note_args = note_args;
        self
    }

    /// Returns new [TransactionArgs] instantiated with the provided auth arguments.
    #[must_use]
    pub fn with_auth_args(mut self, auth_args: Word) -> Self {
        self.auth_args = auth_args;
        self
    }

    // PUBLIC ACCESSORS
    // --------------------------------------------------------------------------------------------

    /// Returns a reference to the transaction script.
    pub fn tx_script(&self) -> Option<&TransactionScript> {
        self.tx_script.as_ref()
    }

    /// Returns the transaction script arguments, or [`EMPTY_WORD`] if the arguments were not
    /// specified.
    ///
    /// These arguments could be potentially used as a key to access the advice map during the
    /// transaction script execution. Notice that the corresponding map entry should be provided
    /// separately during the creation with the [`TransactionArgs::new`] or using the
    /// [`TransactionArgs::extend_advice_map`] method.
    pub fn tx_script_args(&self) -> Word {
        self.tx_script_args
    }

    /// Returns a reference to a specific note argument.
    pub fn get_note_args(&self, note_id: NoteId) -> Option<&Word> {
        self.note_args.get(&note_id)
    }

    /// Returns a reference to the internal [AdviceInputs].
    pub fn advice_inputs(&self) -> &AdviceInputs {
        &self.advice_inputs
    }

    /// Returns a reference to the authentication procedure argument, or [`EMPTY_WORD`] if the
    /// argument was not specified.
    ///
    /// This argument could be potentially used as a key to access the advice map during the
    /// transaction script execution. Notice that the corresponding map entry should be provided
    /// separately during the creation with the [`TransactionArgs::new`] or using the
    /// [`TransactionArgs::extend_advice_map`] method.
    pub fn auth_args(&self) -> Word {
        self.auth_args
    }

    // STATE MUTATORS
    // --------------------------------------------------------------------------------------------

    /// Populates the advice inputs with the expected recipient data for creating output notes.
    ///
    /// The advice inputs' map is extended with the following entries:
    /// - RECIPIENT: [SERIAL_SCRIPT_HASH, STORAGE_COMMITMENT]
    /// - SERIAL_SCRIPT_HASH: [SERIAL_HASH, SCRIPT_ROOT]
    /// - SERIAL_HASH: [SERIAL_NUM, EMPTY_WORD]
    /// - storage_commitment |-> storage_items.
    /// - script_root |-> script.
    pub fn add_output_note_recipient<T: AsRef<NoteRecipient>>(&mut self, note_recipient: T) {
        let note_recipient = note_recipient.as_ref();
        let storage = note_recipient.storage();
        let script = note_recipient.script();
        let script_encoded: Vec<Felt> = script.into();

        // Build the advice map entries
        let script_root: Word = script.root().into();
        let sn_hash = Hasher::merge(&[note_recipient.serial_num(), Word::empty()]);
        let sn_script_hash = Hasher::merge(&[sn_hash, script_root]);

        let new_elements = vec![
            (sn_hash, concat_words(note_recipient.serial_num(), Word::empty())),
            (sn_script_hash, concat_words(sn_hash, script_root)),
            (note_recipient.digest(), concat_words(sn_script_hash, storage.commitment())),
            (storage.commitment(), storage.to_elements()),
            (script_root, script_encoded),
        ];

        self.advice_inputs.extend(AdviceInputs::default().with_map(new_elements));
    }

    /// Adds the `signature` corresponding to `pub_key` on `message` to the advice inputs' map.
    ///
    /// The advice inputs' map is extended with the following key:
    ///
    /// - hash(pub_key, message) |-> signature (prepared for VM execution).
    pub fn add_signature(
        &mut self,
        pub_key: PublicKeyCommitment,
        message: Word,
        signature: Signature,
    ) {
        let pk_word: Word = pub_key.into();
        self.advice_inputs
            .map
            .insert(Hasher::merge(&[pk_word, message]), signature.to_prepared_signature(message));
    }

    /// Populates the advice inputs with the specified note recipient details.
    ///
    /// The advice inputs' map is extended with the following keys:
    ///
    /// - recipient |-> recipient details (inputs_hash, script_root, serial_num).
    /// - storage_commitment |-> storage_items.
    /// - script_root |-> script.
    pub fn extend_output_note_recipients<T, L>(&mut self, notes: L)
    where
        L: IntoIterator<Item = T>,
        T: AsRef<NoteRecipient>,
    {
        for note in notes {
            self.add_output_note_recipient(note);
        }
    }

    /// Extends the internal advice inputs' map with the provided key-value pairs.
    pub fn extend_advice_map<T: IntoIterator<Item = (Word, Vec<Felt>)>>(&mut self, iter: T) {
        self.advice_inputs.map.extend(iter);
    }

    /// Extends the internal advice inputs' merkle store with the provided nodes.
    pub fn extend_merkle_store<I: Iterator<Item = InnerNodeInfo>>(&mut self, iter: I) {
        self.advice_inputs.store.extend(iter);
    }

    /// Extends the advice inputs in self with the provided ones.
    pub fn extend_advice_inputs(&mut self, advice_inputs: AdviceInputs) {
        self.advice_inputs.extend(advice_inputs);
    }
}

/// Concatenates two [`Word`]s into a [`Vec<Felt>`] containing 8 elements.
fn concat_words(first: Word, second: Word) -> Vec<Felt> {
    let mut result = Vec::with_capacity(8);
    result.extend(first);
    result.extend(second);
    result
}

impl Default for TransactionArgs {
    fn default() -> Self {
        Self::new(AdviceMap::default())
    }
}

impl Serializable for TransactionArgs {
    fn write_into<W: ByteWriter>(&self, target: &mut W) {
        self.tx_script.write_into(target);
        self.tx_script_args.write_into(target);
        self.note_args.write_into(target);
        self.advice_inputs.write_into(target);
        self.auth_args.write_into(target);
    }
}

impl Deserializable for TransactionArgs {
    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
        let tx_script = Option::<TransactionScript>::read_from(source)?;
        let tx_script_args = Word::read_from(source)?;
        let note_args = BTreeMap::<NoteId, Word>::read_from(source)?;
        let advice_inputs = AdviceInputs::read_from(source)?;
        let auth_args = Word::read_from(source)?;

        Ok(Self {
            tx_script,
            tx_script_args,
            note_args,
            advice_inputs,
            auth_args,
        })
    }
}

// TRANSACTION SCRIPT ROOT
// ================================================================================================

/// The MAST root of a [`TransactionScript`].
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, WordWrapper)]
pub struct TransactionScriptRoot(Word);

impl From<TransactionScriptRoot> for Word {
    fn from(root: TransactionScriptRoot) -> Self {
        root.0
    }
}

impl Display for TransactionScriptRoot {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        Display::fmt(&self.0, f)
    }
}

impl Serializable for TransactionScriptRoot {
    fn write_into<W: ByteWriter>(&self, target: &mut W) {
        target.write(self.0);
    }

    fn get_size_hint(&self) -> usize {
        self.0.get_size_hint()
    }
}

impl Deserializable for TransactionScriptRoot {
    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
        let word: Word = source.read()?;
        Ok(Self::from_raw(word))
    }
}

// TRANSACTION SCRIPT
// ================================================================================================

/// The attribute name used to mark the entrypoint procedure in a transaction script library.
pub const TRANSACTION_SCRIPT_ATTRIBUTE: &str = "transaction_script";

/// Transaction script.
///
/// A transaction script is a program that is executed in a transaction after all input notes
/// have been executed.
///
/// The [TransactionScript] object is composed of an executable program defined by a [MastForest]
/// and an associated entrypoint.
#[derive(Clone, Debug)]
pub struct TransactionScript {
    mast: Arc<MastForest>,
    entrypoint: MastNodeId,
    package_debug_info: Option<Arc<PackageDebugInfo>>,
}

impl TransactionScript {
    // CONSTRUCTORS
    // --------------------------------------------------------------------------------------------

    /// Returns a new [TransactionScript] instantiated from the provided MAST forest and entrypoint.
    ///
    /// # Panics
    /// Panics if the specified entrypoint is not in the provided MAST forest.
    pub fn from_parts(mast: Arc<MastForest>, entrypoint: MastNodeId) -> Self {
        assert!(mast.get_node_by_id(entrypoint).is_some());

        Self {
            mast,
            entrypoint,
            package_debug_info: None,
        }
    }

    /// Creates a [TransactionScript] from a [`Package`].
    ///
    /// The package must be an executable (i.e., its target type must be
    /// [`TargetType::Executable`](miden_mast_package::TargetType::Executable)).
    ///
    /// # Errors
    /// Returns an error if the package cannot be converted to an executable program.
    pub fn from_package(package: &Package) -> Result<Self, TransactionScriptError> {
        let program =
            package.try_into_program().map_err(TransactionScriptError::PackageNotProgram)?;

        Ok(Self {
            mast: program.mast_forest().clone(),
            entrypoint: program.entrypoint(),
            package_debug_info: package_debug_info(package),
        })
    }

    /// Returns a new [TransactionScript] instantiated from the provided library.
    ///
    /// The library must contain exactly one procedure with the `@transaction_script` attribute,
    /// which will be used as the entrypoint.
    ///
    /// # Errors
    /// Returns an error if:
    /// - The library does not contain a procedure with the `@transaction_script` attribute.
    /// - The library contains multiple procedures with the `@transaction_script` attribute.
    pub fn from_library(library: &Package) -> Result<Self, TransactionScriptError> {
        let mut entrypoint = None;

        for export in library.manifest.exports() {
            if let Some(proc_export) = export.as_procedure()
                && proc_export.attributes.has(TRANSACTION_SCRIPT_ATTRIBUTE)
            {
                if entrypoint.is_some() {
                    return Err(TransactionScriptError::MultipleProceduresWithAttribute);
                }
                entrypoint =
                    Some(proc_export.node.ok_or(TransactionScriptError::NoProcedureWithAttribute)?);
            }
        }

        let entrypoint = entrypoint.ok_or(TransactionScriptError::NoProcedureWithAttribute)?;

        Ok(Self {
            mast: library.mast_forest().clone(),
            entrypoint,
            package_debug_info: package_debug_info(library),
        })
    }

    /// Returns a new [TransactionScript] containing only a reference to a procedure in the
    /// provided library.
    ///
    /// This method is useful when a library contains multiple transaction scripts and you need
    /// to extract a specific one by its fully qualified path (e.g.,
    /// `::miden::standards::tx_scripts::send_notes::main`).
    ///
    /// The procedure at the specified path must have the `@transaction_script` attribute.
    ///
    /// Note: This method creates a minimal [MastForest] containing only an external node
    /// referencing the procedure's digest, rather than copying the entire library. The actual
    /// procedure code will be resolved at runtime via the `MastForestStore`.
    ///
    /// # Errors
    /// Returns an error if:
    /// - The library does not contain a procedure at the specified path.
    /// - The procedure at the specified path does not have the `@transaction_script` attribute.
    pub fn from_library_reference(
        library: &Package,
        path: &Path,
    ) -> Result<Self, TransactionScriptError> {
        // Find the export matching the path
        let export =
            library.manifest.exports().find(|e| e.path().as_ref() == path).ok_or_else(|| {
                TransactionScriptError::ProcedureNotFound(path.to_string().into())
            })?;

        // Get the procedure export and verify it has the @transaction_script attribute
        let proc_export = export
            .as_procedure()
            .ok_or_else(|| TransactionScriptError::ProcedureNotFound(path.to_string().into()))?;

        if !proc_export.attributes.has(TRANSACTION_SCRIPT_ATTRIBUTE) {
            return Err(TransactionScriptError::ProcedureMissingAttribute(path.to_string().into()));
        }

        // Get the digest of the procedure from the library
        let digest = proc_export.digest;

        // Create a minimal MastForest with just an external node referencing the digest
        let (mast, entrypoint) = create_external_node_forest(digest);

        Ok(Self {
            mast: Arc::new(mast),
            entrypoint,
            package_debug_info: package_debug_info(library),
        })
    }

    // PUBLIC ACCESSORS
    // --------------------------------------------------------------------------------------------

    /// Returns a reference to the [MastForest] backing this transaction script.
    pub fn mast(&self) -> Arc<MastForest> {
        self.mast.clone()
    }

    /// Returns the MAST forest and package-owned debug information backing this transaction script.
    pub fn loaded_mast_forest(&self) -> LoadedMastForest {
        loaded_mast_forest(self.mast.clone(), self.package_debug_info.clone())
    }

    /// Returns the commitment of this transaction script (i.e., the script's MAST root).
    pub fn root(&self) -> TransactionScriptRoot {
        TransactionScriptRoot::from_raw(self.mast[self.entrypoint].digest())
    }

    /// Returns a new [TransactionScript] with the provided advice map entries merged into the
    /// underlying [MastForest].
    ///
    /// This allows adding advice map entries to an already-compiled transaction script,
    /// which is useful when the entries are determined after script compilation.
    pub fn with_advice_map(self, advice_map: AdviceMap) -> Self {
        if advice_map.is_empty() {
            return self;
        }

        let mast = (*self.mast).clone().with_advice_map(advice_map);
        Self {
            mast: Arc::new(mast),
            entrypoint: self.entrypoint,
            package_debug_info: self.package_debug_info,
        }
    }
}

impl PartialEq for TransactionScript {
    fn eq(&self, other: &Self) -> bool {
        self.mast == other.mast && self.entrypoint == other.entrypoint
    }
}

impl Eq for TransactionScript {}

// SERIALIZATION
// ================================================================================================

impl Serializable for TransactionScript {
    fn write_into<W: ByteWriter>(&self, target: &mut W) {
        self.mast.write_into(target);
        target.write_u32(u32::from(self.entrypoint));
    }
}

impl Deserializable for TransactionScript {
    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
        let mast = MastForest::read_from(source)?;
        let entrypoint = MastNodeId::from_u32_safe(source.read_u32()?, &mast)?;

        Ok(Self::from_parts(Arc::new(mast), entrypoint))
    }
}

#[cfg(test)]
mod tests {
    use miden_core::advice::AdviceMap;

    use crate::transaction::TransactionArgs;
    use crate::utils::serde::{Deserializable, Serializable};

    #[test]
    fn test_tx_args_serialization() {
        let tx_args = TransactionArgs::new(AdviceMap::default());
        let bytes: std::vec::Vec<u8> = tx_args.to_bytes();
        let decoded = TransactionArgs::read_from_bytes(&bytes).unwrap();

        assert_eq!(tx_args, decoded);
    }

    #[test]
    fn test_transaction_script_preserves_package_debug_info() {
        use super::TransactionScript;
        use crate::assembly::Assembler;

        let assembler = Assembler::default();
        let package =
            assembler.assemble_program("test-transaction-script", "begin nop end").unwrap();
        let script = TransactionScript::from_package(&package).unwrap();

        assert!(script.loaded_mast_forest().package_debug_info().unwrap().is_some());
    }

    #[test]
    fn test_transaction_script_with_advice_map() {
        use miden_core::{Felt, Word};

        use super::TransactionScript;
        use crate::assembly::Assembler;

        let assembler = Assembler::default();
        let package =
            assembler.assemble_program("test-transaction-script", "begin nop end").unwrap();
        let script = TransactionScript::from_package(&package).unwrap();
        assert!(script.mast().advice_map().is_empty());

        // Empty advice map should be a no-op
        let original_root = script.root();
        let script = script.with_advice_map(AdviceMap::default());
        assert_eq!(original_root, script.root());

        // Non-empty advice map should add entries
        let key = Word::from([1u32, 2, 3, 4]);
        let value = vec![Felt::new_unchecked(42), Felt::new_unchecked(43)];
        let mut advice_map = AdviceMap::default();
        advice_map.insert(key, value.clone());

        let script = script.with_advice_map(advice_map);

        let mast = script.mast();
        let stored = mast.advice_map().get(&key).expect("entry should be present");
        assert_eq!(stored.as_ref(), value.as_slice());
    }

    #[test]
    fn test_transaction_script_from_library() {
        use assert_matches::assert_matches;

        use super::TransactionScript;
        use crate::errors::TransactionScriptError;
        use crate::testing::assembler::assemble_test_library;
        use crate::utils::serde::{Deserializable, Serializable};

        let source = "
            @transaction_script
            pub proc main
                push.1 drop
            end
        ";
        let library = assemble_test_library("test-tx-script", "test::tx_script", source);

        let script = TransactionScript::from_library(&library).unwrap();

        // the script must round-trip through serialization unchanged
        let bytes = script.to_bytes();
        let decoded = TransactionScript::read_from_bytes(&bytes).unwrap();
        assert_eq!(script, decoded);

        // a library without the attribute is rejected
        let no_attr = assemble_test_library(
            "test-tx-script-no-attr",
            "test::tx_script_no_attr",
            "pub proc main push.1 drop end",
        );
        assert_matches!(
            TransactionScript::from_library(&no_attr),
            Err(TransactionScriptError::NoProcedureWithAttribute)
        );

        // a library with multiple tagged procedures is rejected
        let multiple = assemble_test_library(
            "test-tx-script-multiple",
            "test::tx_script_multiple",
            "@transaction_script pub proc main_a push.1 drop end
             @transaction_script pub proc main_b push.2 drop end",
        );
        assert_matches!(
            TransactionScript::from_library(&multiple),
            Err(TransactionScriptError::MultipleProceduresWithAttribute)
        );
    }

    #[test]
    fn test_transaction_script_from_library_reference() {
        use alloc::string::ToString;

        use assert_matches::assert_matches;

        use super::TransactionScript;
        use crate::Word;
        use crate::assembly::Path;
        use crate::errors::TransactionScriptError;
        use crate::testing::assembler::assemble_test_library;

        let source = "
            @transaction_script
            pub proc main_a
                push.1 drop
            end

            @transaction_script
            pub proc main_b
                push.2 drop
            end

            pub proc helper
                push.3 drop
            end
        ";
        let library =
            assemble_test_library("test-tx-script-reference", "test::tx_script_reference", source);

        // each tagged procedure can be extracted selectively, and the resulting script's root
        // matches the digest of the referenced procedure
        for proc_name in ["main_a", "main_b"] {
            let export = library
                .manifest
                .exports()
                .find(|e| e.path().as_ref().to_string().ends_with(proc_name))
                .unwrap();
            let digest = export.as_procedure().unwrap().digest;

            let script =
                TransactionScript::from_library_reference(&library, export.path().as_ref())
                    .unwrap();
            assert_eq!(Word::from(script.root()), digest);
        }

        // an unknown path is rejected
        assert_matches!(
            TransactionScript::from_library_reference(&library, Path::new("::foo::bar::main")),
            Err(TransactionScriptError::ProcedureNotFound(_))
        );

        // a procedure without the attribute is rejected
        let helper = library
            .manifest
            .exports()
            .find(|e| e.path().as_ref().to_string().ends_with("helper"))
            .unwrap();
        assert_matches!(
            TransactionScript::from_library_reference(&library, helper.path().as_ref()),
            Err(TransactionScriptError::ProcedureMissingAttribute(_))
        );
    }
}