import EVM from 0xe467b9dd11fa00df import FlowToken from 0x1654653399040a61 import FungibleToken from 0xf233dcee88fe0abe import FlowEVMBridgeUtils from 0x1e4aa0b87d10b141 import FlowEVMBridgeConfig from 0x1e4aa0b87d10b141 import ScopedFTProviders from 0x1e4aa0b87d10b141 import USDCFlow from 0xf1ab99c82dee3526 transaction(amountIn: [UFix64], minAmountOut: UFix64, txdata: [[UInt8]], gasLimit: [UInt64]) { prepare(signer: auth(BorrowValue, CopyValue, SaveValue, IssueStorageCapabilityController) &Account) { let coa = signer.storage.borrow(from: /storage/evm)! let flowVault = signer.storage.borrow(from: /storage/flowTokenVault)! let tokenVault = signer.storage.borrow(from: /storage/usdcFlowVault)! let startBalance = flowVault.balance let startEvmBalance = coa.balance().inFLOW() let scopedProvider <- ScopedFTProviders.createScopedFTProvider( provider: signer.storage.copy>(from: FlowEVMBridgeConfig.providerCapabilityStoragePath)!, filters: [ ScopedFTProviders.AllowanceFilter(FlowEVMBridgeUtils.calculateBridgeFee(bytes: 0)) ], expiration: getCurrentBlock().timestamp + 1.0 ) coa.depositTokens( vault: <-tokenVault.withdraw(amount: amountIn[0]+amountIn[1]), feeProvider: &scopedProvider as auth(FungibleToken.Withdraw) &{FungibleToken.Provider} ) destroy scopedProvider run(coa, tokenAddress: EVM.addressFromString("0x7f27352D5F83Db87a5A3E00f4B07Cc2138D8ee52"), amount: scale(amountIn[0], 6), contractAddress: EVM.addressFromString("0xf45AFe28fd5519d5f8C1d4787a4D5f724C0eFa4d"), txdata: txdata[0], gasLimit: gasLimit[0], ) run(coa, tokenAddress: EVM.addressFromString("0x7f27352D5F83Db87a5A3E00f4B07Cc2138D8ee52"), amount: scale(amountIn[1], 6), contractAddress: EVM.addressFromString("0x3EF68D3f7664b2805D4E88381b64868a56f88bC4"), txdata: txdata[1], gasLimit: gasLimit[1], ) let withdrawBalance = EVM.Balance(attoflow: 0) withdrawBalance.setFLOW(flow: coa.balance().inFLOW() - startEvmBalance) flowVault.deposit(from: <- coa.withdraw(balance: withdrawBalance)) assert( flowVault.balance >= startBalance + minAmountOut, message: flowVault.balance.toString().concat(" < ").concat((startBalance+minAmountOut).toString()) ) } } access(all) fun run(_ coa: auth(EVM.Call) &EVM.CadenceOwnedAccount, tokenAddress: EVM.EVMAddress, amount: UInt256, contractAddress: EVM.EVMAddress, txdata: [UInt8], gasLimit: UInt64) { approveERC20(coa, tokenAddress: tokenAddress, spenderAddress: contractAddress, amount: amount) runCall(coa, contractAddress: contractAddress, txdata: txdata, gasLimit: gasLimit) } access(all) fun runCall(_ coa: auth(EVM.Call) &EVM.CadenceOwnedAccount, contractAddress: EVM.EVMAddress, txdata: [UInt8], gasLimit: UInt64) { let runResult = coa.call(to: contractAddress, data: txdata, gasLimit: gasLimit, value: EVM.Balance(attoflow: 0)) assert(runResult.status == EVM.Status.successful, message: "tx failed. ".concat(formatResultError(runResult))) } access(all) fun approveERC20(_ coa: auth(EVM.Call) &EVM.CadenceOwnedAccount, tokenAddress: EVM.EVMAddress, spenderAddress: EVM.EVMAddress, amount: UInt256) { let approveResult = coa.call(to: tokenAddress, data: EVM.encodeABIWithSignature("approve(address,uint256)", [spenderAddress, amount]), gasLimit: 500_000, value: EVM.Balance(attoflow: 0)) assert(approveResult.status == EVM.Status.successful, message: "approve failed. ".concat(formatResultError(approveResult))) } access(all) fun scale(_ value: UFix64, _ decimals: UInt): UInt256 { pre { decimals <= 18: "Decimals must be less than or equal to 18" } let converted = EVM.Balance(attoflow: 0) converted.setFLOW(flow: value) return UInt256(converted.inAttoFLOW() / powUInt(10, 18 - decimals)) } access(all) fun powUInt(_ base: UInt, _ exponent: UInt): UInt { var value: UInt = 1 var counter: UInt = 0 while counter < exponent { value = value * base counter = counter + 1 } return value } access(all) fun formatResultError(_ callResult: EVM.Result): String { if callResult.status == EVM.Status.successful { return "success" } var status = "failed" if callResult.status == EVM.Status.invalid { status = "invalid" } else if callResult.status == EVM.Status.unknown { status = "unknown" } return "status: ".concat(status).concat(" [").concat(callResult.errorCode.toString()).concat("]: ").concat(callResult.errorMessage) }

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