import FungibleToken from 0xf233dcee88fe0abe import FlowToken from 0x1654653399040a61 import Seussibles from 0x321d8fcde05f6e8c transaction(tibles1to2: [UInt64], tibles2to1: [UInt64]) { let collection1: &Seussibles.Collection let collection2: &Seussibles.Collection let signer1Address: Address let signer2Address: Address let vault: &FlowToken.Vault let vault1: &FlowToken.Vault let vault2: &FlowToken.Vault prepare(signer1: AuthAccount, signer2: AuthAccount, payer: AuthAccount) { assert(signer1.address != signer2.address, message: "signing accounts must be different") assert(!isArrayEqual(tibles1to2, tibles2to1), message: "nft ids must be different") self.signer1Address = signer1.address self.signer2Address = signer2.address self.collection1 = signer1.borrow<&Seussibles.Collection>(from: Seussibles.CollectionStoragePath) ?? panic("Could not borrow collection") self.collection2 = signer2.borrow<&Seussibles.Collection>(from: Seussibles.CollectionStoragePath) ?? panic("Could not borrow collection") self.vault = payer.borrow<&FlowToken.Vault>(from: /storage/flowTokenVault) ?? panic("failed to borrow reference to vault") self.vault1 = signer1.borrow<&FlowToken.Vault>(from: /storage/flowTokenVault) ?? panic("Could not borrow reference to the owner's Vault!") self.vault2 = signer2.borrow<&FlowToken.Vault>(from: /storage/flowTokenVault) ?? panic("Could not borrow reference to the owner's Vault!") } execute { for id in tibles1to2 { let tible <- self.collection1.withdraw(withdrawID: id) self.collection2.deposit(token: <-tible) } for id in tibles2to1 { let tible <- self.collection2.withdraw(withdrawID: id) self.collection1.deposit(token: <-tible) } let signer1PostTransfer = getAccount(self.signer1Address) let signer2PostTransfer = getAccount(self.signer2Address) if (signer1PostTransfer.storageUsed > signer1PostTransfer.storageCapacity) { refillStorage(anAccount: signer1PostTransfer, payerVault: self.vault) } if (signer2PostTransfer.storageUsed > signer2PostTransfer.storageCapacity) { refillStorage(anAccount: signer2PostTransfer, payerVault: self.vault) } } } pub fun refillStorage(anAccount: PublicAccount, payerVault: &FlowToken.Vault) { let flowPerByte = 0.001 / 100000.0 // 0.001 Flow per 100kb storage let storageUsed = UFix64(anAccount.storageUsed) let storageCapacity = UFix64(anAccount.storageCapacity) let flowAmount = (storageUsed - storageCapacity) * flowPerByte let sentVault <- payerVault.withdraw(amount: flowAmount) let anAccountFlowReceiver = anAccount.getCapability(/public/flowTokenReceiver).borrow<&{FungibleToken.Receiver}>() ?? panic("failed to borrow reference to recipient vault") anAccountFlowReceiver.deposit(from: <-sentVault) } pub fun isArrayEqual(_ lhs: [UInt64], _ rhs: [UInt64]): Bool { if lhs.length != rhs.length { return false } var i = 0 while i < lhs.length { if lhs[i] != rhs[i] { return false } i = i + 1 } return true }

Transaction