multiversx_sc_modules/token_merge/
mod.rs

multiversx_sc::imports!();
multiversx_sc::derive_imports!();

pub mod custom_merged_token_attributes;
pub mod merged_token_instances;
pub mod merged_token_setup;

use merged_token_instances::{MergedTokenInstances, MAX_MERGED_TOKENS};

use self::custom_merged_token_attributes::MergedTokenAttributesCreator;

static SC_DOES_NOT_OWN_NFT_PARTS_ERR_MSG: &[u8] = b"NFT parts belong to another merging SC";

const MIN_MERGE_PAYMENTS: usize = 2;

#[multiversx_sc::module]
pub trait TokenMergeModule:
    merged_token_setup::MergedTokenSetupModule
    + crate::default_issue_callbacks::DefaultIssueCallbacksModule
    + crate::pause::PauseModule
{
    fn merge_tokens<AttributesCreator: MergedTokenAttributesCreator<ScType = Self>>(
        &self,
        payments: &ManagedVec<EsdtTokenPayment>,
        attr_creator: &AttributesCreator,
    ) -> EsdtTokenPayment {
        self.require_not_paused();
        require!(
            payments.len() >= MIN_MERGE_PAYMENTS,
            "Must send at least 2 tokens"
        );

        let merged_token_id = self.merged_token().get_token_id();
        let sc_address = self.blockchain().get_sc_address();
        let token_whitelist = self.mergeable_tokens_whitelist();

        let mut already_merged_tokens = ArrayVec::<_, MAX_MERGED_TOKENS>::new();
        let mut single_tokens = ArrayVec::<_, MAX_MERGED_TOKENS>::new();
        for token in payments {
            if token.token_identifier == merged_token_id {
                let token_data = self.blockchain().get_esdt_token_data(
                    &sc_address,
                    &token.token_identifier,
                    token.token_nonce,
                );

                require!(
                    token_data.creator == sc_address,
                    SC_DOES_NOT_OWN_NFT_PARTS_ERR_MSG
                );

                let merged_instances =
                    MergedTokenInstances::decode_from_first_uri(&token_data.uris);
                already_merged_tokens.push(merged_instances);
            } else {
                require!(
                    token_whitelist.contains(&token.token_identifier),
                    "Token {} cannot be merged",
                    (token.token_identifier)
                );

                single_tokens.push(token);
            }
        }

        let mut all_merged_instances = MergedTokenInstances::new();
        for already_merged in already_merged_tokens {
            all_merged_instances.merge_with_other(already_merged);
        }

        for single_token_instance in single_tokens {
            all_merged_instances.add_or_update_instance(single_token_instance.clone());
        }

        let merged_token_payment =
            self.create_merged_token(merged_token_id, &all_merged_instances, attr_creator);

        self.tx()
            .to(ToCaller)
            .payment(&merged_token_payment)
            .transfer_if_not_empty();

        merged_token_payment
    }

    fn split_tokens(
        &self,
        payments: &ManagedVec<EsdtTokenPayment>,
    ) -> ManagedVec<EsdtTokenPayment> {
        self.require_not_paused();
        require!(!payments.is_empty(), "No payments");

        let merged_token_id = self.merged_token().get_token_id();
        let sc_address = self.blockchain().get_sc_address();

        let mut output_payments = ManagedVec::new();
        for token in payments {
            require!(
                token.token_identifier == merged_token_id,
                "Invalid token to split"
            );

            let token_data = self.blockchain().get_esdt_token_data(
                &sc_address,
                &token.token_identifier,
                token.token_nonce,
            );
            require!(
                token_data.creator == sc_address,
                SC_DOES_NOT_OWN_NFT_PARTS_ERR_MSG
            );

            let previously_merged_instance_attributes =
                MergedTokenInstances::decode_from_first_uri(&token_data.uris);
            for inst in previously_merged_instance_attributes.into_instances() {
                output_payments.push(inst);
            }

            self.send()
                .esdt_local_burn(&token.token_identifier, token.token_nonce, &token.amount);
        }

        self.tx().to(ToCaller).payment(&output_payments).transfer();

        output_payments
    }

    fn split_token_partial<AttributesCreator: MergedTokenAttributesCreator<ScType = Self>>(
        &self,
        merged_token: EsdtTokenPayment,
        mut tokens_to_remove: ManagedVec<EsdtTokenPayment>,
        attr_creator: &AttributesCreator,
    ) -> ManagedVec<EsdtTokenPayment> {
        self.require_not_paused();
        self.merged_token()
            .require_same_token(&merged_token.token_identifier);

        let sc_address = self.blockchain().get_sc_address();
        let merged_token_data = self.blockchain().get_esdt_token_data(
            &sc_address,
            &merged_token.token_identifier,
            merged_token.token_nonce,
        );
        require!(
            merged_token_data.creator == sc_address,
            SC_DOES_NOT_OWN_NFT_PARTS_ERR_MSG
        );

        let mut merged_attributes =
            MergedTokenInstances::decode_from_first_uri(&merged_token_data.uris);
        for token in &tokens_to_remove {
            merged_attributes.deduct_balance_for_instance(&token);
        }

        self.send().esdt_local_burn(
            &merged_token.token_identifier,
            merged_token.token_nonce,
            &merged_token.amount,
        );

        // all removed tokens get sent to user, so we can re-use this as output payments
        let new_merged_token = self.create_merged_token(
            merged_token.token_identifier,
            &merged_attributes,
            attr_creator,
        );
        tokens_to_remove.push(new_merged_token);

        self.tx().to(ToCaller).payment(&tokens_to_remove).transfer();

        tokens_to_remove
    }
}
multiversx_sc_modules/token_merge/mod.rs

multiversx_sc_modules/token_merge/
mod.rs
