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IncrementFiFlashloanConnectors

import FungibleToken from 0xf233dcee88fe0abe import DeFiActions from 0x6d888f175c158410 import SwapInterfaces from 0xb78ef7afa52ff906 import SwapConfig from 0xb78ef7afa52ff906 import SwapFactory from 0xb063c16cac85dbd1 /// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! /// THIS CONTRACT IS IN BETA AND IS NOT FINALIZED - INTERFACES MAY CHANGE AND/OR PENDING CHANGES MAY REQUIRE REDEPLOYMENT /// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! /// /// IncrementFiFlashloanConnectors /// /// DeFiActions adapter implementations fitting IncrementFi protocols to the DeFiActions Flasher interface. /// access(all) contract IncrementFiFlashloanConnectors { /// Canonical path in which to store the generic FlashLoanExecutor resource access(all) let ExecutorStoragePath: StoragePath /* --- CONSTRUCTS --- */ /// Flasher /// /// A DeFiActions connector that performs flash loans using IncrementFi's SwapPair contract /// access(all) struct Flasher : DeFiActions.Flasher { /// The address of the SwapPair contract to use for flash loans access(all) let pairAddress: Address /// The type of token to borrow access(all) let type: Type /// Capability to the FlashLoanExecutor resource access(self) let executor: Capability<&{SwapInterfaces.FlashLoanExecutor}> /// An optional identifier allowing protocols to identify stacked connector operations by defining a protocol- /// specific Identifier to associated connectors on construction access(contract) var uniqueID: DeFiActions.UniqueIdentifier? init( pairAddress: Address, type: Type, executor: Capability<&{SwapInterfaces.FlashLoanExecutor}>, uniqueID: DeFiActions.UniqueIdentifier? ) { pre { executor.check(): "Invalid SwapInterfaces.FlashLoanExecutor capability provided" } let pair = getAccount(pairAddress).capabilities.borrow<&{SwapInterfaces.PairPublic}>(SwapConfig.PairPublicPath) ?? panic("Could not reference SwapPair public capability at address \(pairAddress)") let pairInfo = pair.getPairInfoStruct() assert(pairInfo.token0Key == type.identifier || pairInfo.token1Key == type.identifier, message: "Provided type is not supported by the SwapPair at address \(pairAddress) - " .concat("valid types for this SwapPair are \(pairInfo.token0Key) and \(pairInfo.token1Key)")) self.pairAddress = pairAddress self.type = type self.executor = executor self.uniqueID = uniqueID } /// Returns a ComponentInfo struct containing information about this Flasher and its inner DFA components /// /// @return a ComponentInfo struct containing information about this component and a list of ComponentInfo for /// each inner component in the stack. /// access(all) fun getComponentInfo(): DeFiActions.ComponentInfo { return DeFiActions.ComponentInfo( type: self.getType(), id: self.id(), innerComponents: [] ) } /// Returns a copy of the struct's UniqueIdentifier, used in extending a stack to identify another connector in /// a DeFiActions stack. See DeFiActions.align() for more information. /// /// @return a copy of the struct's UniqueIdentifier /// access(contract) view fun copyID(): DeFiActions.UniqueIdentifier? { return self.uniqueID } /// Sets the UniqueIdentifier of this component to the provided UniqueIdentifier, used in extending a stack to /// identify another connector in a DeFiActions stack. See DeFiActions.align() for more information. /// /// @param id: the UniqueIdentifier to set for this component /// access(contract) fun setID(_ id: DeFiActions.UniqueIdentifier?) { self.uniqueID = id } /// Returns the asset type this Flasher can issue as a flash loan /// /// @return the type of token this Flasher can issue as a flash loan /// access(all) view fun borrowType(): Type { return self.type } /// Returns the estimated fee for a flash loan of the specified amount /// /// @param loanAmount: The amount of tokens to borrow /// @return the estimated fee for a flash loan of the specified amount /// access(all) fun calculateFee(loanAmount: UFix64): UFix64 { return UFix64(SwapFactory.getFlashloanRateBps()) * loanAmount / 10000.0 } /// Performs a flash loan of the specified amount. The callback function is passed the fee amount, a Vault /// containing the loan, and the data. The callback function should return a Vault containing the loan + fee. /// /// @param amount: The amount of tokens to borrow /// @param data: Optional data to pass to the callback function /// @param callback: The callback function to use for the flash loan /// access(all) fun flashLoan( amount: UFix64, data: AnyStruct?, callback: fun(UFix64, @{FungibleToken.Vault}, AnyStruct?): @{FungibleToken.Vault} // fee, loan, data ) { // get the SwapPair public capability on which to perform the flash loan let pair = getAccount(self.pairAddress).capabilities.borrow<&{SwapInterfaces.PairPublic}>( SwapConfig.PairPublicPath ) ?? panic("Could not reference SwapPair public capability at address \(self.pairAddress)") // cast data to expected params type and add fee and callback to params for the callback function let params = data as! {String: AnyStruct}? ?? {} params["fee"] = self.calculateFee(loanAmount: amount) params["callback"] = callback // perform the flash loan pair.flashloan( executor: self._borrowExecutor(), requestedTokenVaultType: self.type, requestedAmount: amount, params: params ) } /// Returns a reference to the FlashLoanExecutor capability /// /// @return a reference to the FlashLoanExecutor capability /// access(self) fun _borrowExecutor(): &{SwapInterfaces.FlashLoanExecutor} { return self.executor.borrow() ?? panic("Could not borrow FlashLoanExecutor capability") } } /// FlashLoanExecutor /// /// A resource that implements the SwapInterfaces.FlashLoanExecutor interface and is used to execute flash loans. /// This resource is required to in order to execute flash loans on IncrementFi's SwapPair contract, but is made /// generically to be used in conjunction with the Flasher DeFiActions connector defined in this contract. Instead /// of statically declaring the logic within the Executor's executeAndRepay() function, the callback function is /// passed as a parameter to the executeAndRepay() function via the params object indexed by "callback". /// access(all) resource Executor : SwapInterfaces.FlashLoanExecutor { /// Performs a flash loan of the specified amount. The Flasher.flashLoan() callback function should be found in /// the params object passed to this function under the key "callback". The callback function is passed the fee /// amount, a Vault containing the loan, and the data. The callback function should return a Vault containing /// the loan + fee. access(all) fun executeAndRepay(loanedToken: @{FungibleToken.Vault}, params: {String: AnyStruct}): @{FungibleToken.Vault} { // cast params to expected types and execute the callback let fee = params.remove(key: "fee") as? UFix64 ?? panic("No fee provided in params to executeAndRepay") let callback = params.remove(key: "callback") as? fun(UFix64, @{FungibleToken.Vault}, AnyStruct?): @{FungibleToken.Vault} ?? panic("No callback function provided in params to executeAndRepay") // execute the callback logic let repaidToken <- callback(fee, <-loanedToken, params) // return the repaid token return <- repaidToken } } /* --- PUBLIC FUNCTIONS --- */ /// Creates a new FlashLoanExecutor resource /// /// @return a new FlashLoanExecutor resource /// access(all) fun createExecutor(): @Executor { return <- create Executor() } init() { self.ExecutorStoragePath = StoragePath(identifier: "IncrementFiFlashloanConnectorsExecutor_\(self.account.address)")! } }