# IFrictionlessFXSwap [Git Source](https://gitlab.com/dfyclabs/protocol/dfyclabs-tokens/blob/4d02dc52d2d09cdfeac84c93627e866efb85b602/contracts/interface/IFrictionlessFXSwap.sol) **Inherits:** IAbstractFeeModule **Author:** DEFYCA Labs S.à.r.l Copyright © 2023 DEFYCA Labs S.à.r.l Permission is hereby granted, free of charge, to any person obtaining a copy of the Frictionless protocol smart contracts (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL DEFYCA LABS S.à.r.l BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Interface defining the frictionless conversion and atomic swapping of any `FrictionlessFundDepositToken` currency pair on the Frictionless protocol. The FX rates are set from the live spot & forward FX partners on the protocol. ## Functions ### setFXDeskFeeAddr *Sets the address of the FXDesk fee recipient Only Owner (PROTOCOL\_ADMIN) can call this function* ```solidity function setFXDeskFeeAddr(address newFXDeskFeeAddr_) external; ``` **Parameters** | Name | Type | Description | | ------------------- | --------- | ------------------------------------------- | | `newFXDeskFeeAddr_` | `address` | The new address of the FXDesk fee recipient | ### setSwapFees *Set the swap fees for the swaps of a token pair. The fees can be any combination of zero (0%) or upto 10000 bps (100%) on any directional transfer. Fees can only be set by the Owner (PROTOCOL\_ADMIN).* ```solidity function setSwapFees( FrictionlessTokenFXFeeInfo calldata token0FeeInfo_, FrictionlessTokenFXFeeInfo calldata token1FeeInfo_ ) external; ``` **Parameters** | Name | Type | Description | | ---------------- | ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `token0FeeInfo_` | `FrictionlessTokenFXFeeInfo` | The fees associated with the token0 (first token) in the token pair during the swap. | | `token1FeeInfo_` | `FrictionlessTokenFXFeeInfo` | The fees associated with the token1 (second token) in the token pair during the swap. throws `FrictionlessFXSwapInvalidTokenAddresses` if the token addresses are invalid. throws `FrictionlessFXSwapInvalidFeeRecipientAddr` if the feeRecipientAddr doesn't equal to the `fxDeskFeeAddr`. throws `AbstractFeeModuleInvalidFeeRecipient` if the feeRecipientAddr is a zero address throws `AbstractFeeModuleInvalidFee` if the feeInBps is not in the valid range (ZERO\_FEES\_IN\_BPS to MAX\_FEES\_IN\_BPS) emits `FrictionlessFeeSet` upon completion of the setting of the fee info for the token in either set of fees | ### setTokenFee *Set the fee associated with the swap of a Token and manages the mapping of the key to this set of Fees. Can only be set by the Owner (PROTOCOL\_ADMIN).* ```solidity function setTokenFee(bytes32 tokenFeeKey_, FrictionlessTokenFXFeeInfo calldata tokenFeeInfo_) external; ``` **Parameters** | Name | Type | Description | | --------------- | ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `tokenFeeKey_` | `bytes32` | The key, generated by the function `getTokenFeeKey`, which is used to map a specific swap polarity for tokens. | | `tokenFeeInfo_` | `FrictionlessTokenFXFeeInfo` | The fees associated with the swap of token, used in the calculation and disbursement of fees during swap of a token pair. throws `FrictionlessFXSwapInvalidTokenAddresses` if the token addresses are invalid. throws `FrictionlessFXSwapInvalidFeeRecipientAddr` if the feeRecipientAddr doesn't equal to the `fxDeskFeeAddr`. throws `AbstractFeeModuleInvalidFeeRecipient` if the feeRecipientAddr is a zero address throws `AbstractFeeModuleInvalidFee` if the feeInBps is not in the valid range (ZERO\_FEES\_IN\_BPS to MAX\_FEES\_IN\_BPS) emits `FrictionlessTokenFeeSet` upon completion of the setting of the fee info for the token | ### swapTokens *Swaps tokens between addresses at a specified exchange rate Only PROTOCOL\_TREASURY can call this function* ```solidity function swapTokens( address sellingTokenAddr_, address buyingTokenAddr_, address tokenSender_, address tokenRecipient_, uint256 buyingTokensAmount_, uint256 buyingTokenExchangeRate_ ) external; ``` **Parameters** | Name | Type | Description | | -------------------------- | --------- | ------------------------------------------------------------------- | | `sellingTokenAddr_` | `address` | The address of the token to be sold | | `buyingTokenAddr_` | `address` | The address of the token to be bought | | `tokenSender_` | `address` | The address of the sender initiating the swap | | `tokenRecipient_` | `address` | The address where the bought tokens will be sent | | `buyingTokensAmount_` | `uint256` | The amount of tokens being bought | | `buyingTokenExchangeRate_` | `uint256` | The exchange rate of the token being bought to the token being sold | ### fxDeskFeeAddr *Retrieves the address of the FXDesk fee recipient* ```solidity function fxDeskFeeAddr() external view returns (address); ``` **Returns** | Name | Type | Description | | -------- | --------- | --------------------------------------- | | `` | `address` | The address of the FXDesk fee recipient | ### treasuryManager *Retrieves the Frictionless Treasury Manager contract* ```solidity function treasuryManager() external view returns (IFrictionlessTreasuryManager); ``` **Returns** | Name | Type | Description | | -------- | ------------------------------ | --------------------------------------------------------- | | `` | `IFrictionlessTreasuryManager` | The address of the Frictionless Treasury Manager contract | ### permissionManager *Retrieves the Frictionless Permissions Manager contract* ```solidity function permissionManager() external view returns (IFrictionlessPermissionsManager); ``` **Returns** | Name | Type | Description | | -------- | --------------------------------- | ------------------------------------------------------------ | | `` | `IFrictionlessPermissionsManager` | The address of the Frictionless Permissions Manager contract | ### getSwapFeesInfo *get the tokenFeeInfo set for the fees associated per token in an exchange.* ```solidity function getSwapFeesInfo(address token0_, address token1_) external view returns (FeeInfo memory, FeeInfo memory); ``` **Parameters** | Name | Type | Description | | --------- | --------- | ---------------------------------------------- | | `token0_` | `address` | the address of the first token in an exchange | | `token1_` | `address` | the address of the second token in an exchange | **Returns** | Name | Type | Description | | -------- | --------- | ------------------------------------------------------------- | | `` | `FeeInfo` | FeeInfo set for the fees associated per token in an exchange. | | `` | `FeeInfo` | | ### getSwapFeeKeys *Generates keys based on the packed encoding of the addresses of sets of tokens using the keccak256 hashing function. Used to store tokenFees in mappings.* ```solidity function getSwapFeeKeys(address token0_, address token1_) external view returns (bytes32, bytes32); ``` **Parameters** | Name | Type | Description | | --------- | --------- | -------------------------------------------------------- | | `token0_` | `address` | the address of the token 0 in a transfer fee calculation | | `token1_` | `address` | the address of the token 1 in a transfer fee calculation | **Returns** | Name | Type | Description | | -------- | --------- | ---------------------------------------------------------------------------------------------------------- | | `` | `bytes32` | keys based on the packed encoding of the addresses of sets of tokens using the keccak256 hashing function. | | `` | `bytes32` | | ### getTokenFeeKey *Generates a key based on the packed encoding of the addresses of both tokens using the keccak256 hashing function. Used to store tokenFees in mappings.* ```solidity function getTokenFeeKey(address token0_, address token1_) external view returns (bytes32); ``` **Parameters** | Name | Type | Description | | --------- | --------- | -------------------------------------------------------- | | `token0_` | `address` | the address of the token 0 in a transfer fee calculation | | `token1_` | `address` | the address of the token 1 in a transfer fee calculation | **Returns** | Name | Type | Description | | -------- | --------- | ------------------------------------------------------------------------------------------------------------------ | | `` | `bytes32` | generates a key based on the packed encoding of the addresses of both tokens using the keccak256 hashing function. | ### getSellingTokensAmount *Calculates the amount of selling tokens based on the buying amount and exchange rate* ```solidity function getSellingTokensAmount(uint256 buyingTokensAmount_, uint256 buyingTokenExchangeRate_) external view returns (uint256); ``` **Parameters** | Name | Type | Description | | -------------------------- | --------- | ------------------------------------------------------------------- | | `buyingTokensAmount_` | `uint256` | The amount of tokens being bought | | `buyingTokenExchangeRate_` | `uint256` | The exchange rate of the token being bought to the token being sold | **Returns** | Name | Type | Description | | -------- | --------- | ---------------------------- | | `` | `uint256` | The amount of selling tokens | ## Events ### FrictionlessFXTokensSwapped *Event emitted upon successful token swaps* ```solidity event FrictionlessFXTokensSwapped( address sellingTokenAddr, address buyingTokenAddr, address tokenSender, address tokenRecipient, uint256 sellingTokensAmount, uint256 buyingTokensAmount, uint256 buyingTokenExchangeRate ); ``` ## Errors ### FrictionlessFXSwapInvalidTokenAddresses *error thrown during `setSwapFees` if token adresses are invalid (zero addresses, equals addresses and etc.).* ```solidity error FrictionlessFXSwapInvalidTokenAddresses(address token0, address token1); ``` ### FrictionlessFXSwapInvalidFeeRecipientAddr *error thrown during `setSwapFees`, `setTokenFee` and `swapTokens` if the fxDeskFeeRecipient doesn't equal to the stored `fxDeskFeeAddr`* ```solidity error FrictionlessFXSwapInvalidFeeRecipientAddr(address newFeeRecipient); ``` ### FrictionlessFXSwapNotEnoughPermissions *error thrown during `swapTokens` if the msg.sender is not a PROTOCOL\_TREASURY.* ```solidity error FrictionlessFXSwapNotEnoughPermissions(); ``` ## Structs ### FrictionlessTokenFXFeeInfo *Structure representing token fee information including the token address and fee information* ```solidity struct FrictionlessTokenFXFeeInfo { address tokenAddr; uint256 feeAbsoluteLimit; FeeInfo feeInfo; } ```