An advanced Ethereum/EVM mobile wallet
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alpha-wallet-ios/AlphaWallet/Market/OrderHandler.swift

156 lines
5.0 KiB

// Copyright © 2018 Stormbird PTE. LTD.
import BigInt
import TrustWalletCore
public struct Order {
var price: BigUInt
var indices: [UInt16]
var expiry: BigUInt
var contractAddress: AlphaWallet.Address
var count: BigUInt
var nonce: BigUInt
var tokenIds: [BigUInt]?
var spawnable: Bool
var nativeCurrencyDrop: Bool
}
public struct SignedOrder {
var order: Order
var message: [UInt8]
var signature: String
}
extension String {
var hexToBytes: [UInt8] {
let hex: [Character]
if count % 2 == 0 {
hex = Array(self)
} else {
hex = Array(("0" + self))
}
return stride(from: 0, to: count, by: 2).compactMap {
UInt8(String(hex[$0..<$0.advanced(by: 2)]), radix: 16)
}
}
}
extension BinaryInteger {
var data: Data {
var source = self
return Data(bytes: &source, count: MemoryLayout<Self>.size)
}
}
extension Data {
var array: [UInt8] {
return Array(self)
}
}
public class OrderHandler {
private let keystore: EtherKeystore
init(keystore: EtherKeystore) {
self.keystore = keystore
}
func signOrders(orders: [Order], account: AlphaWallet.Address, tokenType: TokenType) throws -> [SignedOrder] {
let messages = createMessagesFromOrders(orders: orders, tokenType: tokenType)
return try! bulkSignOrders(messages: messages, account: account, orders: orders)
}
private func createMessagesFromOrders(orders: [Order], tokenType: TokenType) -> [Data] {
var messages = [Data]()
switch tokenType {
case .erc721ForTickets:
for order in orders {
let message: [UInt8] = encodeMessageForTrade(
price: order.price,
expiryBuffer: order.expiry,
tokenIds: order.tokenIds ?? [BigUInt](),
contractAddress: order.contractAddress
)
messages.append(Data(bytes: message))
}
case .erc875:
for order in orders {
let message: [UInt8] = encodeMessageForTrade(
price: order.price,
expiryBuffer: order.expiry,
indices: order.indices,
contractAddress: order.contractAddress
)
messages.append(Data(bytes: message))
}
case .erc721, .nativeCryptocurrency, .erc20:
break
}
return messages
}
private func bulkSignOrders(messages: [Data], account: AlphaWallet.Address, orders: [Order]) throws -> [SignedOrder] {
var signedOrders = [SignedOrder]()
let signatures = try! keystore.signMessageBulk(messages, for: account).dematerialize()
for i in 0..<signatures.count {
let signedOrder = SignedOrder(
order: orders[i],
message: messages[i].bytes,
signature: signatures[i].hexString
)
signedOrders.append(signedOrder)
}
return signedOrders
}
func encodeMessageForTrade(
price: BigUInt,
expiryBuffer: BigUInt,
indices: [UInt16],
contractAddress: AlphaWallet.Address
) -> [UInt8] {
let arrayLength: Int = 84 + indices.count * 2
var buffer = [UInt8]()
buffer.reserveCapacity(arrayLength)
let priceInWei = UniversalLinkHandler.padTo32(Array(price.serialize()))
let expiry = UniversalLinkHandler.padTo32(Array(expiryBuffer.serialize()))
buffer.append(contentsOf: priceInWei)
buffer.append(contentsOf: expiry)
//no leading zeros issue here
buffer.append(contentsOf: contractAddress.eip55String.hexToBytes)
let tokensUint8 = OrderHandler.uInt16ArrayToUInt8(arrayOfUInt16: indices)
buffer.append(contentsOf: tokensUint8)
return buffer
}
func encodeMessageForTrade(
price: BigUInt,
expiryBuffer: BigUInt,
tokenIds: [BigUInt],
contractAddress: AlphaWallet.Address
) -> [UInt8] {
let arrayLength: Int = 84 + tokenIds.count * 32
var buffer = [UInt8]()
buffer.reserveCapacity(arrayLength)
let priceInWei = Array(price.serialize())
let expiry = Array(expiryBuffer.serialize())
buffer.append(contentsOf: UniversalLinkHandler.padTo32(priceInWei))
buffer.append(contentsOf: UniversalLinkHandler.padTo32(expiry))
buffer.append(contentsOf: contractAddress.eip55String.hexToBytes)
for token in tokenIds {
buffer.append(contentsOf: UniversalLinkHandler.padTo32(token.serialize().array))
}
return buffer
}
public static func uInt16ArrayToUInt8(arrayOfUInt16: [UInt16]) -> [UInt8] {
var arrayOfUint8 = [UInt8]()
for i in 0..<arrayOfUInt16.count {
let UInt8ArrayPair = arrayOfUInt16[i].bigEndian.data.array
arrayOfUint8.append(UInt8ArrayPair[0])
arrayOfUint8.append(UInt8ArrayPair[1])
}
return arrayOfUint8
}
}