miden-standards 0.16.0-alpha.3

use alloc::vec::Vec;

use miden_protocol::account::AccountId;
use miden_protocol::assembly::Path;
use miden_protocol::asset::{Asset, FungibleAsset, NonFungibleAsset};
use miden_protocol::crypto::rand::FeltRng;
use miden_protocol::errors::NoteError;
use miden_protocol::note::{
    Note,
    NoteAssets,
    NoteAttachment,
    NoteAttachments,
    NoteRecipient,
    NoteScript,
    NoteScriptRoot,
    NoteStorage,
    NoteTag,
    NoteType,
    PartialNoteMetadata,
};
use miden_protocol::utils::sync::LazyLock;
use miden_protocol::{Felt, MAX_NOTE_STORAGE_ITEMS, Word};

use crate::StandardsLib;

// NOTE SCRIPT
// ================================================================================================

/// Path to the MINT note script procedure in the standards library.
const MINT_SCRIPT_PATH: &str = "::miden::standards::notes::mint::main";

// Initialize the MINT note script only once
static MINT_SCRIPT: LazyLock<NoteScript> = LazyLock::new(|| {
    let standards_lib = StandardsLib::default();
    let path = Path::new(MINT_SCRIPT_PATH);
    NoteScript::from_library_reference(standards_lib.as_ref(), path)
        .expect("Standards library contains MINT note script procedure")
});

// MINT NOTE
// ================================================================================================

/// A MINT note: instructs a network faucet to mint the asset embedded in its storage.
///
/// The single MINT script works against both fungible and non-fungible faucets: it detects the
/// faucet kind by reflection (via the `CodeInspection` component) and calls the matching
/// `mint_and_send`. The script reads the asset (a fungible asset, or a non-fungible commitment)
/// directly from the note's storage. For fungible faucets the embedded `ASSET_ID` binds the note
/// to one faucet, so a MINT note bound to faucet A cannot be redirected to faucet B. MINT notes are
/// always public (for network execution) and carry no assets; the output note minted on
/// consumption can be private or public depending on the [`MintNoteStorage`] variant.
///
/// Construct one with the [builder](MintNote::builder); convert it into a protocol [`Note`]
/// infallibly via `Note::from`.
#[derive(Debug, Clone)]
pub struct MintNote {
    sender: AccountId,
    storage: MintNoteStorage,
    serial_number: Word,
    attachments: NoteAttachments,
}

#[bon::bon]
impl MintNote {
    /// Builds a new [`MintNote`] that mints the asset embedded in `mint_storage`.
    ///
    /// # Errors
    ///
    /// Returns an error if the attachments exceed their protocol limit (see
    /// [`NoteAttachments::new`]).
    #[builder]
    pub fn new(
        #[builder(field)] attachments: Vec<NoteAttachment>,
        sender: AccountId,
        #[builder(name = mint_storage)] storage: MintNoteStorage,
        serial_number: Word,
    ) -> Result<Self, NoteError> {
        let attachments = NoteAttachments::new(attachments)?;

        Ok(Self {
            sender,
            storage,
            serial_number,
            attachments,
        })
    }
}

impl MintNote {
    // CONSTANTS
    // --------------------------------------------------------------------------------------------

    /// Expected number of storage items of a fungible MINT note (private mode).
    ///
    /// Layout: RECIPIENT(4) + ASSET_ID(4) + ASSET_VALUE(4) + tag(1).
    pub const NUM_STORAGE_ITEMS_PRIVATE: usize = 13;

    /// Minimum number of storage items of a fungible MINT note (public mode).
    ///
    /// Layout: SCRIPT_ROOT(4) + SERIAL_NUM(4) + ASSET_ID(4) + ASSET_VALUE(4) + tag(1) +
    /// padding(3) + variable output-note storage. The variable portion starts at offset 20
    /// (word-aligned) and may contain zero or more items.
    pub const MIN_NUM_STORAGE_ITEMS_PUBLIC: usize = 20;

    /// Expected number of storage items of a non-fungible MINT note (private mode).
    ///
    /// Layout: RECIPIENT(4) + COMMITMENT(4) + tag(1).
    pub const NON_FUNGIBLE_NUM_STORAGE_ITEMS_PRIVATE: usize = 9;

    /// Minimum number of storage items of a non-fungible MINT note (public mode).
    ///
    /// Layout: SCRIPT_ROOT(4) + SERIAL_NUM(4) + COMMITMENT(4) + tag(1) + padding(3) + variable
    /// output-note storage. The variable portion starts at offset 16 (word-aligned).
    pub const NON_FUNGIBLE_MIN_NUM_STORAGE_ITEMS_PUBLIC: usize = 16;

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

    /// Returns the script of the MINT note.
    pub fn script() -> NoteScript {
        MINT_SCRIPT.clone()
    }

    /// Returns the MINT note script root.
    pub fn script_root() -> NoteScriptRoot {
        MINT_SCRIPT.root()
    }

    /// Returns the account ID of the faucet that will mint the asset.
    pub fn faucet_id(&self) -> AccountId {
        self.storage.faucet_id()
    }

    /// Returns the account ID of the note's sender (the faucet owner).
    pub fn sender(&self) -> AccountId {
        self.sender
    }

    /// Returns the note's storage configuration.
    pub fn storage(&self) -> &MintNoteStorage {
        &self.storage
    }

    /// Returns the note's serial number.
    pub fn serial_number(&self) -> Word {
        self.serial_number
    }

    /// Returns the attachments carried by the note.
    pub fn attachments(&self) -> &NoteAttachments {
        &self.attachments
    }
}

// BUILDER EXTENSIONS
// ================================================================================================

impl<S: mint_note_builder::State> MintNoteBuilder<S> {
    /// Adds a single attachment to the note.
    pub fn attachment(mut self, attachment: impl Into<NoteAttachment>) -> Self {
        self.attachments.push(attachment.into());
        self
    }

    /// Adds multiple attachments to the note.
    pub fn attachments(
        mut self,
        attachments: impl IntoIterator<Item = impl Into<NoteAttachment>>,
    ) -> Self {
        self.attachments.extend(attachments.into_iter().map(Into::into));
        self
    }
}

impl<S: mint_note_builder::State> MintNoteBuilder<S>
where
    S::SerialNumber: mint_note_builder::IsUnset,
{
    /// Draws a serial number from `rng` and sets it on the builder.
    pub fn generate_serial_number(
        self,
        rng: &mut impl FeltRng,
    ) -> MintNoteBuilder<mint_note_builder::SetSerialNumber<S>> {
        self.serial_number(rng.draw_word())
    }
}

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

impl From<MintNote> for Note {
    fn from(note: MintNote) -> Self {
        // MINT notes are always public for network execution and carry no assets; the asset to mint
        // lives in the note's storage.
        let faucet_id = note.storage.faucet_id();
        let metadata = PartialNoteMetadata::new(note.sender, NoteType::Public)
            .with_tag(NoteTag::with_account_target(faucet_id));
        let recipient = NoteRecipient::new(
            note.serial_number,
            MintNote::script(),
            NoteStorage::from(note.storage),
        );

        Note::with_attachments(NoteAssets::default(), metadata, recipient, note.attachments)
    }
}

// MINT NOTE STORAGE
// ================================================================================================

/// Represents the different storage formats for MINT notes.
///
/// The MINT note serves both fungible and non-fungible faucets. The fungible variants embed a
/// [`FungibleAsset`] (`ASSET_ID` + `ASSET_VALUE`, 8 felts) so the faucet executing the note can be
/// checked against the asset's faucet ID at mint time. The non-fungible variants embed a
/// [`NonFungibleAsset`], whose value word (`ASSET_VALUE`, 4 felts) is the asset commitment and
/// whose faucet ID routes the note.
///
/// - Fungible private (13 items): RECIPIENT + ASSET_ID + ASSET_VALUE + tag.
/// - Fungible public (20+ items): SCRIPT_ROOT + SERIAL_NUM + ASSET_ID + ASSET_VALUE + tag +
///   padding(3) + variable output-note storage (word-aligned at offset 20).
/// - Non-fungible private (9 items): RECIPIENT + COMMITMENT + tag.
/// - Non-fungible public (16+ items): SCRIPT_ROOT + SERIAL_NUM + COMMITMENT + tag + padding(3) +
///   variable output-note storage (word-aligned at offset 16).
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum MintNoteStorage {
    FungiblePrivate {
        recipient_digest: Word,
        asset: FungibleAsset,
        tag: NoteTag,
    },
    FungiblePublic {
        recipient: NoteRecipient,
        asset: FungibleAsset,
        tag: NoteTag,
    },
    NonFungiblePrivate {
        recipient_digest: Word,
        asset: NonFungibleAsset,
        tag: NoteTag,
    },
    NonFungiblePublic {
        recipient: NoteRecipient,
        asset: NonFungibleAsset,
        tag: NoteTag,
    },
}

impl MintNoteStorage {
    /// Builds fungible private-mode storage (creates a private output note).
    pub fn new_fungible_private(
        recipient_digest: Word,
        asset: FungibleAsset,
        tag: NoteTag,
    ) -> Self {
        Self::FungiblePrivate { recipient_digest, asset, tag }
    }

    /// Builds fungible public-mode storage (creates a public output note).
    pub fn new_fungible_public(
        recipient: NoteRecipient,
        asset: FungibleAsset,
        tag: NoteTag,
    ) -> Result<Self, NoteError> {
        let total_storage_items =
            MintNote::MIN_NUM_STORAGE_ITEMS_PUBLIC + recipient.storage().num_items() as usize;

        if total_storage_items > MAX_NOTE_STORAGE_ITEMS {
            return Err(NoteError::TooManyStorageItems(total_storage_items));
        }

        Ok(Self::FungiblePublic { recipient, asset, tag })
    }

    /// Builds non-fungible private-mode storage (creates a private output note).
    pub fn new_non_fungible_private(
        recipient_digest: Word,
        asset: NonFungibleAsset,
        tag: NoteTag,
    ) -> Self {
        Self::NonFungiblePrivate { recipient_digest, asset, tag }
    }

    /// Builds non-fungible public-mode storage (creates a public output note).
    pub fn new_non_fungible_public(
        recipient: NoteRecipient,
        asset: NonFungibleAsset,
        tag: NoteTag,
    ) -> Result<Self, NoteError> {
        let total_storage_items = MintNote::NON_FUNGIBLE_MIN_NUM_STORAGE_ITEMS_PUBLIC
            + recipient.storage().num_items() as usize;

        if total_storage_items > MAX_NOTE_STORAGE_ITEMS {
            return Err(NoteError::TooManyStorageItems(total_storage_items));
        }

        Ok(Self::NonFungiblePublic { recipient, asset, tag })
    }

    /// Returns the account ID of the faucet that will mint the asset.
    pub fn faucet_id(&self) -> AccountId {
        match self {
            Self::FungiblePrivate { asset, .. } | Self::FungiblePublic { asset, .. } => {
                asset.faucet_id()
            },
            Self::NonFungiblePrivate { asset, .. } | Self::NonFungiblePublic { asset, .. } => {
                asset.faucet_id()
            },
        }
    }
}

impl From<MintNoteStorage> for NoteStorage {
    fn from(mint_storage: MintNoteStorage) -> Self {
        match mint_storage {
            MintNoteStorage::FungiblePrivate { recipient_digest, asset, tag } => {
                let mut storage_values = Vec::with_capacity(MintNote::NUM_STORAGE_ITEMS_PRIVATE);
                storage_values.extend_from_slice(recipient_digest.as_elements());
                storage_values.extend_from_slice(&Asset::from(asset).as_elements());
                storage_values.push(tag.into());
                NoteStorage::new(storage_values)
                    .expect("number of storage items should not exceed max storage items")
            },
            MintNoteStorage::FungiblePublic { recipient, asset, tag } => {
                let mut storage_values = Vec::new();
                storage_values.extend_from_slice(recipient.script().root().as_elements());
                storage_values.extend_from_slice(recipient.serial_num().as_elements());
                storage_values.extend_from_slice(&Asset::from(asset).as_elements());
                // tag followed by 3 padding felts so the variable storage that follows starts at
                // a word-aligned offset (20).
                storage_values.extend_from_slice(&[tag.into(), Felt::ZERO, Felt::ZERO, Felt::ZERO]);
                storage_values.extend_from_slice(recipient.storage().items());
                NoteStorage::new(storage_values)
                    .expect("number of storage items should not exceed max storage items")
            },
            MintNoteStorage::NonFungiblePrivate { recipient_digest, asset, tag } => {
                let mut storage_values =
                    Vec::with_capacity(MintNote::NON_FUNGIBLE_NUM_STORAGE_ITEMS_PRIVATE);
                storage_values.extend_from_slice(recipient_digest.as_elements());
                storage_values.extend_from_slice(asset.to_value_word().as_elements());
                storage_values.push(tag.into());
                NoteStorage::new(storage_values)
                    .expect("number of storage items should not exceed max storage items")
            },
            MintNoteStorage::NonFungiblePublic { recipient, asset, tag } => {
                let mut storage_values = Vec::new();
                storage_values.extend_from_slice(recipient.script().root().as_elements());
                storage_values.extend_from_slice(recipient.serial_num().as_elements());
                storage_values.extend_from_slice(asset.to_value_word().as_elements());
                // tag followed by 3 padding felts so the variable storage that follows starts at
                // a word-aligned offset (16).
                storage_values.extend_from_slice(&[tag.into(), Felt::ZERO, Felt::ZERO, Felt::ZERO]);
                storage_values.extend_from_slice(recipient.storage().items());
                NoteStorage::new(storage_values)
                    .expect("number of storage items should not exceed max storage items")
            },
        }
    }
}

// TESTS
// ================================================================================================

#[cfg(test)]
mod tests {
    use miden_protocol::account::AccountType;
    use miden_protocol::crypto::rand::RandomCoin;

    use super::*;

    fn faucet() -> AccountId {
        AccountId::builder().account_type(AccountType::Public).build_with_seed([1; 32])
    }

    fn owner() -> AccountId {
        AccountId::builder().account_type(AccountType::Private).build_with_seed([2; 32])
    }

    /// The builder produces a public, asset-less note tagged for the faucet.
    #[test]
    fn builder_builds_public_mint_note() {
        let mut rng = RandomCoin::new(Word::empty());
        let asset = FungibleAsset::new(faucet(), 50).unwrap();
        let mint_storage =
            MintNoteStorage::new_fungible_private(Word::empty(), asset, NoteTag::default());
        let mint_note = MintNote::builder()
            .sender(owner())
            .mint_storage(mint_storage)
            .generate_serial_number(&mut rng)
            .build()
            .unwrap();

        assert_eq!(mint_note.faucet_id(), faucet());
        assert_eq!(mint_note.sender(), owner());

        let note = Note::from(mint_note);
        assert_eq!(note.metadata().note_type(), NoteType::Public);
        assert_eq!(note.metadata().tag(), NoteTag::with_account_target(faucet()));
        assert_eq!(note.assets().num_assets(), 0);
    }
}