ERC20 tokens support (#141)

- implement available balance in adapters
- add fee error for ERC20

BankWallet/BankWallet/Core/Adapters/BitcoinAdapter.swift

@@ -4,6 +4,7 @@ import RxSwift
 
 class BitcoinAdapter {
     let decimal = 8
+    let feeCoinCode: CoinCode? = nil
 
     let coin: Coin
 
@@ -110,13 +111,19 @@ extension BitcoinAdapter: IAdapter {
         }
     }
 
-    func fee(for value: Decimal, address: String?, senderPay: Bool) throws -> Decimal {
+    func availableBalance(for address: String?) -> Decimal {
+        return max(0, balance - fee(for: balance, address: address, senderPay: true))
+    }
+
+    func fee(for value: Decimal, address: String?, senderPay: Bool) -> Decimal {
         do {
             let amount = convertToSatoshi(value: value)
             let fee = try bitcoinKit.fee(for: amount, toAddress: address, senderPay: senderPay)
             return Decimal(fee) / coinRate
         } catch SelectorError.notEnough(let maxFee) {
-            throw FeeError.insufficientAmount(fee: Decimal(maxFee) / coinRate)
+            return Decimal(maxFee) / coinRate
+        } catch {
+            return 0
         }
     }
 
@@ -129,6 +136,14 @@ extension BitcoinAdapter: IAdapter {
         try bitcoinKit.validate(address: address)
     }
 
+    func validate(amount: Decimal, address: String?, senderPay: Bool) -> [SendStateError] {
+        var errors = [SendStateError]()
+        if amount > availableBalance(for: address) {
+            errors.append(.insufficientAmount)
+        }
+        return errors
+    }
+
     func parse(paymentAddress: String) -> PaymentRequestAddress {
         let paymentData = bitcoinKit.parse(paymentAddress: paymentAddress)
         return PaymentRequestAddress(address: paymentData.address, amount: paymentData.amount.map { Decimal($0) })

BankWallet/BankWallet/Core/Adapters/Erc20Adapter.swift

@@ -3,6 +3,7 @@ import RxSwift
 
 class Erc20Adapter: EthereumBaseAdapter {
     let contractAddress: String
+    let feeCoinCode: CoinCode? = "ETH"
 
     init(coin: Coin, ethereumKit: EthereumKit, contractAddress: String, decimal: Int) {
         self.contractAddress = contractAddress
@@ -36,12 +37,23 @@ extension Erc20Adapter: IAdapter {
         ethereumKit.erc20Send(to: address, contractAddress: contractAddress, value: value, gasPrice: nil, completion: completion)
     }
 
-    func fee(for value: Decimal, address: String?, senderPay: Bool) throws -> Decimal {
-        let fee =  ethereumKit.erc20Fee
-        if ethereumKit.balance > 0, ethereumKit.balance - fee < 0 {
-            throw FeeError.insufficientAmount(fee: fee)
+    func availableBalance(for address: String?) -> Decimal {
+        return balance
+    }
+
+    func fee(for value: Decimal, address: String?, senderPay: Bool) -> Decimal {
+        return ethereumKit.erc20Fee
+    }
+
+    func validate(amount: Decimal, address: String?, senderPay: Bool) -> [SendStateError] {
+        var errors = [SendStateError]()
+        if amount > availableBalance(for: address) {
+            errors.append(.insufficientAmount)
+        }
+        if ethereumKit.balance < fee(for: amount, address: address, senderPay: senderPay) {
+            errors.append(.insufficientFeeBalance)
         }
-        return fee
+        return errors
     }
 
 }

BankWallet/BankWallet/Core/Adapters/EthereumAdapter.swift

@@ -2,6 +2,7 @@ import HSEthereumKit
 import RxSwift
 
 class EthereumAdapter: EthereumBaseAdapter {
+    let feeCoinCode: CoinCode? = nil
 
     init(coin: Coin, ethereumKit: EthereumKit) {
         super.init(coin: coin, ethereumKit: ethereumKit, decimal: 18)
@@ -32,12 +33,20 @@ extension EthereumAdapter: IAdapter {
         ethereumKit.send(to: address, value: value, gasPrice: nil, completion: completion)
     }
 
-    func fee(for value: Decimal, address: String?, senderPay: Bool) throws -> Decimal {
-        let fee = ethereumKit.fee
-        if balance > 0, balance - value - fee < 0 {
-            throw FeeError.insufficientAmount(fee: fee)
+    func availableBalance(for address: String?) -> Decimal {
+        return max(0, balance - fee(for: balance, address: address, senderPay: true))
+    }
+
+    func fee(for value: Decimal, address: String?, senderPay: Bool) -> Decimal {
+        return ethereumKit.fee
+    }
+
+    func validate(amount: Decimal, address: String?, senderPay: Bool) -> [SendStateError] {
+        var errors = [SendStateError]()
+        if amount > availableBalance(for: address) {
+            errors.append(.insufficientAmount)
         }
-        return fee
+        return errors
     }
 
 }

BankWallet/BankWallet/Core/Managers/AppConfigProvider.swift

@@ -47,11 +47,10 @@ class AppConfigProvider: IAppConfigProvider {
     ]
 
     var defaultCoins: [Coin] {
-        let suffix = testMode ? "t" : ""
         return [
-            Coin(title: "Bitcoin", code: "BTC\(suffix)", type: .bitcoin),
-            Coin(title: "Bitcoin Cash", code: "BCH\(suffix)", type: .bitcoinCash),
-            Coin(title: "Ethereum", code: "ETH\(suffix)", type: .ethereum),
+            Coin(title: "Bitcoin", code: "BTC", type: .bitcoin),
+            Coin(title: "Bitcoin Cash", code: "BCH", type: .bitcoinCash),
+            Coin(title: "Ethereum", code: "ETH", type: .ethereum),
         ]
     }
 

BankWallet/BankWallet/Core/Protocols.swift

@@ -77,12 +77,9 @@ enum AdapterState {
     case notSynced
 }
 
-enum FeeError: Error {
-    case insufficientAmount(fee: Decimal)
-}
-
 protocol IAdapter: class {
     var coin: Coin { get }
+    var feeCoinCode: CoinCode? { get }
 
     var decimal: Int { get }
     var balance: Decimal { get }
@@ -111,8 +108,10 @@ protocol IAdapter: class {
 
     func send(to address: String, value: Decimal, completion: ((Error?) -> ())?)
 
-    func fee(for value: Decimal, address: String?, senderPay: Bool) throws -> Decimal
+    func availableBalance(for address: String?) -> Decimal
+    func fee(for value: Decimal, address: String?, senderPay: Bool) -> Decimal
     func validate(address: String) throws
+    func validate(amount: Decimal, address: String?, senderPay: Bool) -> [SendStateError]
     func parse(paymentAddress: String) -> PaymentRequestAddress
 
     var receiveAddress: String { get }

BankWallet/BankWallet/Modules/Send/SendInteractor.swift

@@ -85,60 +85,45 @@ extension SendInteractor: ISendInteractor {
             }
         }
 
-        var feeValue: Decimal?
-        if let coinValue = sendState.coinValue {
-            do {
-                let value = try adapter.fee(for: coinValue.value, address: input.address, senderPay: true)
-                feeValue = value
-            } catch FeeError.insufficientAmount(let fee) {
-                feeValue = fee
-                sendState.amountError = createAmountError(forInput: input, fee: fee)
-            } catch {
-                print("unhandled error: \(error)")
+        let errors = adapter.validate(amount: sendState.coinValue?.value ?? 0, address: input.address, senderPay: true)
+        errors.forEach {
+            switch($0) {
+            case .insufficientAmount: sendState.amountError = createAmountError(forInput: input)
+            case .insufficientFeeBalance: break//sendState.feeError = createAmountError(forInput: input)
             }
         }
-        if let feeValue = feeValue {
+        if let coinValue = sendState.coinValue {
+            let feeValue = adapter.fee(for: coinValue.value, address: input.address, senderPay: true)
             sendState.feeCoinValue = CoinValue(coinCode: coinCode, value: feeValue)
         }
-
         if let rateValue = state.rateValue, let feeCoinValue = sendState.feeCoinValue {
             sendState.feeCurrencyValue = CurrencyValue(currency: baseCurrency, value: rateValue * feeCoinValue.value)
         }
 
         return sendState
     }
 
-    private func createAmountError(forInput input: SendUserInput, fee: Decimal) -> AmountError? {
-        var balanceMinusFee = state.adapter.balance - fee
-        if balanceMinusFee < 0 {
-            balanceMinusFee = 0
-        }
+    private func createAmountError(forInput input: SendUserInput) -> AmountError? {
+        let availableBalance = state.adapter.availableBalance(for: input.address)
         switch input.inputType {
         case .coin:
-            return AmountError.insufficientAmount(amountInfo: .coinValue(coinValue: CoinValue(coinCode: coin.code, value: balanceMinusFee)))
+            return .insufficientAmount(amountInfo: .coinValue(coinValue: CoinValue(coinCode: coin.code, value: availableBalance)))
         case .currency:
             return state.rateValue.map {
-                let currencyBalanceMinusFee = balanceMinusFee * $0
-                return AmountError.insufficientAmount(amountInfo: .currencyValue(currencyValue: CurrencyValue(currency: currencyManager.baseCurrency, value: currencyBalanceMinusFee)))
+                let currencyBalanceMinusFee = availableBalance * $0
+                return .insufficientAmount(amountInfo: .currencyValue(currencyValue: CurrencyValue(currency: currencyManager.baseCurrency, value: currencyBalanceMinusFee)))
             }
         }
     }
 
     func totalBalanceMinusFee(forInputType input: SendInputType, address: String?) -> Decimal {
-        var fee: Decimal
-        do {
-            fee = try state.adapter.fee(for: state.adapter.balance, address: address, senderPay: false)
-        } catch {
-            print(error)
-            return 0
-        }
-        let balanceMinusFee = state.adapter.balance - fee
+        let availableBalance =  state.adapter.availableBalance(for: address)
         switch input {
         case .coin:
-            return balanceMinusFee
+            return availableBalance
         case .currency:
             return state.rateValue.map {
-                return balanceMinusFee * $0
+                return availableBalance * $0
             } ?? 0
         }
     }

BankWallet/BankWallet/Modules/Send/SendModule.swift

@@ -74,6 +74,11 @@ enum SendInputType: String {
     case currency = "currency"
 }
 
+enum SendStateError {
+    case insufficientAmount
+    case insufficientFeeBalance
+}
+
 enum AmountError: Error {
     case insufficientAmount(amountInfo: AmountInfo)
 }
@@ -118,6 +123,7 @@ class SendState {
     var coinValue: CoinValue?
     var currencyValue: CurrencyValue?
     var amountError: AmountError?
+    var feeError: AmountError?
     var address: String?
     var addressError: AddressError?
     var feeCoinValue: CoinValue?