Fee integration

eth-connector/src/connector.rs

@@ -1,3 +1,4 @@
+use crate::fee::{Fee, FeeType};
 use crate::{connector_impl::FinishDepositCallArgs, Proof, VerifyProofArgs, WithdrawResult};
 use aurora_engine_types::types::Address;
 use near_contract_standards::storage_management::StorageBalance;
@@ -10,6 +11,23 @@ pub trait Deposit {
     fn deposit(&mut self, #[serializer(borsh)] raw_proof: Proof) -> Promise;
 }
 
+#[ext_contract(ext_fee_manage)]
+pub trait FeeManagement {
+    fn get_deposit_fee_per_silo(&self, silo: Option<AccountId>) -> Option<Fee>;
+    fn get_withdraw_fee_per_silo(&self, silo: Option<AccountId>) -> Option<Fee>;
+    fn get_fee_owner(&self) -> AccountId;
+    fn calculate_fee_amount(
+        &self,
+        amount: U128,
+        fee_type: FeeType,
+        silo: Option<AccountId>,
+    ) -> U128;
+    fn set_deposit_fee_per_silo(&mut self, silo: Option<AccountId>, fee: Option<Fee>);
+    fn set_withdraw_fee_per_silo(&mut self, silo: Option<AccountId>, fee: Option<Fee>);
+    fn set_fee_owner(&mut self, owner: Option<AccountId>);
+    fn claim_fee(&mut self, amount: U128, receiver_id: Option<AccountId>);
+}
+
 #[ext_contract(ext_withdraw)]
 pub trait Withdraw {
     #[result_serializer(borsh)]

eth-connector/src/connector_impl.rs

@@ -38,7 +38,7 @@ pub struct FinishDepositCallArgs {
 }
 
 /// withdraw result for eth-connector
-#[derive(BorshSerialize, BorshDeserialize)]
+#[derive(BorshSerialize, BorshDeserialize, Debug, PartialEq, Eq)]
 pub struct WithdrawResult {
     pub amount: Balance,
     pub recipient_id: Address,

eth-connector/src/fee.rs

@@ -0,0 +1,35 @@
+use near_sdk::{
+    borsh::{self, BorshDeserialize, BorshSerialize},
+    collections::UnorderedMap,
+    json_types::U128,
+    serde::{Deserialize, Serialize},
+    AccountId,
+};
+
+#[derive(Copy, Debug, Serialize, Deserialize, Clone)]
+pub enum FeeType {
+    Deposit,
+    Withdraw,
+}
+
+#[derive(BorshDeserialize, BorshSerialize, Debug, Clone, Serialize, Deserialize, Copy)]
+pub struct Fee {
+    /// Fee percentage in 6 decimal precision (10% -> 0.1 * 10e6 -> 100_000)
+    pub fee_percentage: u32,
+    /// The minimum fee amount for transfer
+    pub lower_bound: Option<U128>,
+    /// The maximum fee amount for transfer
+    pub upper_bound: Option<U128>,
+}
+
+#[derive(BorshDeserialize, BorshSerialize)]
+pub struct FeeStorage {
+    /// Store the fee for deposit transfers that target silos.
+    /// The `None` is used to store the default fee.
+    pub deposit_fee_per_silo: UnorderedMap<Option<AccountId>, Fee>,
+    /// Store the fee for withdrawal transfers initiated by silos.
+    /// The `None` is used to store the default fee.
+    pub withdraw_fee_per_silo: UnorderedMap<Option<AccountId>, Fee>,
+    /// If set, then fee minted to the `fee_owner` account
+    pub fee_owner: Option<AccountId>,
+}