taler-ios

iOS apps for GNU Taler (wallet)
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WalletCore.swift (35351B)


      1 /*
      2  * This file is part of GNU Taler, ©2022-25 Taler Systems S.A.
      3  * See LICENSE.md
      4  */
      5 /**
      6  * @author Marc Stibane
      7  * @author Iván Ávalos
      8  */
      9 import SwiftUI              // FOUNDATION has no AppStorage
     10 import AnyCodable
     11 import SymLog
     12 import os
     13 import LocalConsole
     14 
     15 /// Delegate for the wallet backend.
     16 protocol WalletBackendDelegate {
     17     /// Called when the backend interface receives a message it does not know how to handle.
     18     func walletBackendReceivedUnknownMessage(_ walletCore: WalletCore, message: String)
     19 }
     20 
     21 // MARK: -
     22 /// An interface to the wallet backend.
     23 class WalletCore: QuickjsMessageHandler {
     24     public static let shared = try! WalletCore()          // will (and should) crash on failure
     25     private let symLog = SymLogC()
     26 
     27     @AppStorage("logTransactions") var logTransactions: Bool = false
     28 
     29     private var queue: DispatchQueue
     30     private var semaphore: DispatchSemaphore
     31 
     32     private let quickjs: Quickjs
     33     private var requestsMade: UInt          // counter for array of completion closures
     34     private var completions: [UInt : (Date, (UInt, Date, String?, Data?, TalerErrorDetail?) -> Void)] = [:]
     35     var delegate: WalletBackendDelegate?
     36 
     37     var versionInfo: VersionInfo?           // shown in SettingsView
     38     var nativeDB: Bool
     39     var isObserving: Int
     40     var isLogging: Bool
     41     let logger = Logger(subsystem: "net.taler.gnu", category: "WalletCore")
     42 
     43     private var expired: [String] = []      // save txID of expired items to not beep twice
     44 
     45     private struct FullRequest: Encodable {
     46         let operation: String
     47         let id: UInt
     48         let args: AnyEncodable
     49     }
     50 
     51     private struct FullResponse: Decodable {
     52         let type: String
     53         let operation: String
     54         let id: UInt
     55         let result: AnyCodable
     56     }
     57     
     58     struct FullError: Decodable {
     59         let type: String
     60         let operation: String
     61         let id: UInt
     62         let error: TalerErrorDetail
     63     }
     64 
     65     var lastError: FullError?
     66 
     67     struct ResponseOrNotification: Decodable {
     68         let type: String
     69         let operation: String?
     70         let id: UInt?
     71         let result: AnyCodable?
     72         let error: TalerErrorDetail?
     73         let payload: AnyCodable?
     74     }
     75 
     76     /// the bare envelope, which still decodes when the full `ResponseOrNotification` doesn't
     77     private struct ResponseHeader: Decodable {
     78         let type: String
     79         let id: UInt?
     80     }
     81 
     82     struct Payload: Decodable {
     83         let type: String
     84         let id: String?
     85         let reservePub: String?
     86         let isInternal: Bool?
     87         let hintTransactionId: String?
     88         let event: [String: AnyCodable]?
     89         let exchangeBaseUrl: String?
     90         let newExchangeState: ExchangeState?
     91         let operation: String?      // indexeddb-to-native-migration
     92         let phase: String?          // fixup | copy | verify | complete | failed
     93         let error: TalerErrorDetail?    // only when phase is "failed"
     94         let step: String?           // config | currencyInfo | contacts | mailboxMessages | mailboxConfigurations | contractTerms | tombstones | operationRetries | bankAccounts | globalCurrencyExchanges | globalCurrencyAuditors | exchangeBaseUrlFixups | exchangeBaseUrlMigrationLog | reserves | exchanges | exchangeDetails | exchangeSignKeys | denominationFamilies | denominations | withdrawalGroups | purchases | refreshGroups | coins | planchets | refreshSessions | coinHistory | coinAvailability | refundGroups | tokens | slates | depositGroups | recoupGroups | denomLossEvents | peerPushDebit | peerPushCredit | peerPullDebit | peerPullCredit | donationSummaries | donationPlanchets | donationReceipts | transactionsMeta | refundItems
     95         let completedSteps: Int?
     96         let totalSteps: Int?
     97         let processedRecords: Int?
     98         let totalRecords: Int?
     99         let completionPercent: Int?
    100     }
    101 
    102     deinit {
    103         logger.log("shutdown Quickjs")
    104     // TODO: send shutdown message to talerWalletInstance
    105 //        quickjs.waitStopped()
    106     }
    107 
    108     init() throws {
    109         nativeDB = false
    110         isObserving = 0
    111         isLogging = false
    112 //        logger.trace("init Quickjs")
    113         requestsMade = 0
    114         queue = DispatchQueue(label: "net.taler.myQueue", attributes: .concurrent)
    115         semaphore = DispatchSemaphore(value: 1)
    116         quickjs = Quickjs()
    117         quickjs.messageHandler = self
    118         logger.log("Quickjs running")
    119     }
    120 }
    121 // MARK: -  completionHandler functions
    122 extension WalletCore {
    123     /// `requestsMade` and `completions` are touched both from the request queue and from
    124     /// wallet-core's message handler, thus every access must be guarded by the semaphore.
    125     private func reserveRequestId() -> UInt {
    126         semaphore.wait()
    127         defer { semaphore.signal() }
    128         let requestId = requestsMade
    129         requestsMade += 1
    130         return requestId
    131     }
    132 
    133     private func setCompletion(_ requestId: UInt, _ sendTime: Date,
    134                                _ completion: @escaping (UInt, Date, String?, Data?, TalerErrorDetail?) -> Void) {
    135         semaphore.wait()
    136         defer { semaphore.signal() }
    137         completions[requestId] = (sendTime, completion)
    138     }
    139 
    140     /// Take the completion out of the list, so that it can never be called twice.
    141     /// Whoever gets it must call it - on every path, including all error paths.
    142     private func takeCompletion(_ requestId: UInt)
    143                              -> (Date, (UInt, Date, String?, Data?, TalerErrorDetail?) -> Void)? {
    144         semaphore.wait()
    145         defer { semaphore.signal() }
    146         return completions.removeValue(forKey: requestId)
    147     }
    148 
    149     private func handleError(_ decoded: ResponseOrNotification, _ message: String?) throws {
    150         guard let requestId = decoded.id else {
    151             logger.error("didn't find requestId in error response")
    152             // TODO: show error alert
    153             throw WalletBackendError.deserializationError
    154         }
    155         guard let (timeSent, completion) = takeCompletion(requestId) else {
    156             logger.error("requestId \(requestId, privacy: .public) not in list")
    157             // TODO: show error alert
    158             throw WalletBackendError.deserializationError
    159         }
    160         if let walletError = decoded.error {            // wallet-core sent an error message
    161             do {
    162                 let jsonData = try JSONEncoder().encode(walletError)
    163                 let responseCode = walletError.code
    164                 logger.error("wallet-core sent back error \(walletError.code, privacy: .public), \(responseCode, privacy: .public) for request \(requestId, privacy: .public)")
    165                 symLog.log("id:\(requestId)  \(walletError)")
    166                 completion(requestId, timeSent, message, jsonData, walletError)
    167             } catch {        // JSON encoding of response.result failed / should never happen
    168                 symLog.log(decoded)
    169                 logger.error("cannot encode wallet-core Error")
    170                 completion(requestId, timeSent, message, nil, WalletCore.parseFailureError())
    171             }
    172         } else {             // JSON decoding of error message failed
    173             completion(requestId, timeSent, message, nil, WalletCore.parseFailureError())
    174         }
    175     }
    176 
    177     private func handleResponse(_ decoded: ResponseOrNotification, _ message: String) throws {
    178         guard let requestId = decoded.id else {
    179             logger.error("didn't find requestId in response")
    180             symLog.log(decoded)                 // TODO: .error
    181             throw WalletBackendError.deserializationError
    182         }
    183         guard let (timeSent, completion) = takeCompletion(requestId) else {
    184             logger.error("requestId \(requestId, privacy: .public) not in list")
    185             throw WalletBackendError.deserializationError
    186         }
    187         guard let result = decoded.result else {        // don't throw - we own the completion now
    188             logger.error("requestId \(requestId, privacy: .public) got no result")
    189             completion(requestId, timeSent, message, nil, WalletCore.parseResponseError())
    190             return
    191         }
    192         do {
    193             let jsonData = try JSONEncoder().encode(result)
    194             if let operation = decoded.operation {
    195                 if operation == "getTransactionsV2" {
    196                     if logTransactions {
    197                         symLog.log(message)
    198                     }
    199                 } else {
    200                     if #available(iOS 16.0, *) {
    201                         let regex = #/"data:image(.*?)"/#
    202                         let modString = message.replacing(regex, with: "\"XXX\"")
    203                         symLog.log(modString)
    204                     } else {
    205                         symLog.log(message)
    206                     }
    207 
    208                 }
    209             }
    210 //            logger.info(result)   TODO: log result
    211             completion(requestId, timeSent, message, jsonData, nil)
    212         } catch {        // JSON encoding of response.result failed / should never happen
    213             symLog.log(result)                 // TODO: .error
    214             completion(requestId, timeSent, message, nil, WalletCore.parseResponseError())
    215         }
    216     }
    217 
    218     @MainActor
    219     private func postNotificationM(_ aName: NSNotification.Name,
    220                            object anObject: Any? = nil,
    221                                   userInfo: [AnyHashable: Any]? = nil) async {
    222         NotificationCenter.default.post(name: aName, object: anObject, userInfo: userInfo)
    223     }
    224     private func postNotification(_ aName: NSNotification.Name,
    225                           object anObject: Any? = nil,
    226                                  userInfo: [AnyHashable: Any]? = nil) {
    227         Task { // runs on MainActor
    228             await postNotificationM(aName, object: anObject, userInfo: userInfo)
    229 //            logger.info("Notification sent: \(aName.rawValue, privacy: .public)")
    230         }
    231     }
    232 
    233     @MainActor
    234     private func handleRequestProgressError(_ jsonData: Data) throws {
    235         do {
    236             let decoded = try JSONDecoder().decode(RequestProgressError.self, from: jsonData)
    237             DispatchQueue.main.async {
    238                 Controller.shared.lastProgressError = decoded
    239                 self.postNotification(.RequestProgressError,
    240                                       userInfo: [NOTIFICATIONERROR: decoded])
    241             }
    242         }
    243     }
    244 
    245     @MainActor
    246     private func handleRequestProgressPhase(_ jsonData: Data) throws {
    247         do {
    248             let decoded = try JSONDecoder().decode(RequestProgressPhase.self, from: jsonData)
    249             DispatchQueue.main.async {
    250                 Controller.shared.lastProgressPhase = decoded
    251                 self.postNotification(.RequestProgressPhase,
    252                              userInfo: [NOTIFICATIONPHASE: decoded])
    253             }
    254         }
    255     }
    256 
    257     private func handlePendingProcessed(_ payload: Payload) throws {
    258         guard let id = payload.id else {
    259             throw WalletBackendError.deserializationError
    260         }
    261         let pendingOp = Notification.Name.PendingOperationProcessed.rawValue
    262         if id.hasPrefix("exchange-update:") {
    263             // Bla Bla Bla
    264         } else if id.hasPrefix("refresh:") {
    265             // Bla Bla Bla
    266         } else if id.hasPrefix("purchase:") {
    267             // TODO: handle purchase
    268 //            symLog.log("\(pendingOp): \(id)")
    269         } else if id.hasPrefix("withdraw:") {
    270             // TODO: handle withdraw
    271 //            symLog.log("\(pendingOp): \(id)")
    272         } else if id.hasPrefix("peer-pull-credit:") {
    273             // TODO: handle peer-pull-credit
    274 //            symLog.log("\(pendingOp): \(id)")
    275         } else if id.hasPrefix("peer-push-debit:") {
    276             // TODO: handle peer-push-debit
    277 //            symLog.log("\(pendingOp): \(id)")
    278         } else {
    279             // TODO: handle other pending-operation-processed
    280             logger.log("❗️ \(pendingOp, privacy: .public): \(id, privacy: .public)")        // this is a new pendingOp I haven't seen before
    281         }
    282     }
    283     @MainActor
    284     private func handleStateTransition(_ jsonData: Data) throws {
    285         do {
    286             let decoded = try JSONDecoder().decode(TransactionTransition.self, from: jsonData)
    287             if let errorInfo = decoded.errorInfo {
    288                 // reload pending transaction list to add error badge
    289                 postNotification(.TransactionError, userInfo: [NOTIFICATIONERROR: WalletBackendError.walletCoreError(errorInfo)])
    290             } else {
    291                 guard decoded.newTxState != decoded.oldTxState else {
    292                     logger.info("handleStateTransition: No State change: \(decoded.transactionId, privacy: .private(mask: .hash))")
    293                     return
    294                 }
    295             }
    296 
    297             let components = decoded.transactionId.components(separatedBy: ":")
    298             if components.count >= 3 {  // txn:$txtype:$uid
    299                 if let type = TransactionType(rawValue: components[1]) {
    300                     guard type != .refresh else { return }
    301                     let newMajor = decoded.newTxState.major
    302                     let newMinor = decoded.newTxState.minor
    303                     let oldMinor = decoded.oldTxState?.minor
    304                     switch newMajor {
    305                         case .done:
    306                             logger.info("handleStateTransition: Done: \(decoded.transactionId, privacy: .private(mask: .hash))")
    307                             if type.isWithdrawal {
    308                                 Controller.shared.playSound(2)  // play payment_received only for withdrawals
    309                             } else if !type.isIncoming {
    310                                 if !(oldMinor == .autoRefund || oldMinor == .acceptRefund) {
    311                                     Controller.shared.playSound(1)  // play payment_sent for all outgoing tx
    312                                 }
    313                             } else {    // incoming but not withdrawal
    314                                 logger.info("    incoming payment done - NO sound - \(type.rawValue)")
    315                             }
    316                             postNotification(.TransactionDone, userInfo: [TRANSACTIONTRANSITION: decoded])
    317                             return
    318                         case .aborting, .aborted:
    319                             logger.log("handleStateTransition: Aborting: \(decoded.transactionId, privacy: .private(mask: .hash))")
    320                             postNotification(.TransactionStateTransition, userInfo: [TRANSACTIONTRANSITION: decoded])
    321                         case .expired, .deleted:
    322                             logger.warning("handleStateTransition: Expired: \(decoded.transactionId, privacy: .private(mask: .hash))")
    323                             if let index = expired.firstIndex(of: components[2]) {
    324                                 expired.remove(at: index)                       // don't beep twice
    325                             } else {
    326                                 expired.append(components[2])
    327                                 Controller.shared.playSound(0)                  // beep at first sight
    328                             }
    329                             postNotification(.TransactionExpired, userInfo: [TRANSACTIONTRANSITION: decoded])
    330                         case .pending:
    331                             if let newMinor {
    332                                 if newMinor == .ready {
    333                                     logger.log("handleStateTransition: PendingReady: \(decoded.transactionId, privacy: .private(mask: .hash))")
    334                                     postNotification(.PendingReady, userInfo: [TRANSACTIONTRANSITION: decoded])
    335                                     return
    336                                 } else if newMinor == .exchangeWaitReserve      // user did confirm on bank website
    337                                        || newMinor == .withdraw {               // coin-withdrawal has started
    338 //                                    logger.log("DismissSheet: \(decoded.transactionId, privacy: .private(mask: .hash))")
    339                                     postNotification(.DismissSheet, userInfo: [TRANSACTIONTRANSITION: decoded])
    340                                     return
    341                                 } else if newMinor == .kyc {       // user did confirm on bank website, but KYC is needed
    342                                     logger.log("handleStateTransition: KYCrequired: \(decoded.transactionId, privacy: .private(mask: .hash))")
    343                                     postNotification(.KYCrequired, userInfo: [TRANSACTIONTRANSITION: decoded])
    344                                     return
    345                                 }
    346                                 logger.trace("handleStateTransition: Pending:\(newMinor.rawValue, privacy: .public) \(decoded.transactionId, privacy: .private(mask: .hash))")
    347                             } else {
    348                                 logger.trace("handleStateTransition: Pending: \(decoded.transactionId, privacy: .private(mask: .hash))")
    349                             }
    350                             postNotification(.TransactionStateTransition, userInfo: [TRANSACTIONTRANSITION: decoded])
    351                         default:
    352                             if let newMinor {
    353                                 logger.log("handleStateTransition: \(newMajor.rawValue, privacy: .public):\(newMinor.rawValue, privacy: .public) \(decoded.transactionId, privacy: .private(mask: .hash))")
    354                             } else {
    355                                 logger.warning("handleStateTransition: \(newMajor.rawValue, privacy: .public): \(decoded.transactionId, privacy: .private(mask: .hash))")
    356                             }
    357                             postNotification(.TransactionStateTransition, userInfo: [TRANSACTIONTRANSITION: decoded])
    358                     } // switch
    359                 } // type
    360             } // 3 components
    361             return
    362         } catch DecodingError.dataCorrupted(let context) {
    363             logger.error("handleStateTransition: \(context.debugDescription)")
    364         } catch DecodingError.keyNotFound(let key, let context) {
    365             logger.error("handleStateTransition: Key '\(key.stringValue)' not found:\(context.debugDescription)")
    366             logger.error("\(context.codingPath)")
    367         } catch DecodingError.valueNotFound(let value, let context) {
    368             logger.error("handleStateTransition: Value '\(value)' not found:\(context.debugDescription)")
    369             logger.error("\(context.codingPath)")
    370         } catch DecodingError.typeMismatch(let type, let context) {
    371             logger.error("handleStateTransition: Type '\(type)' mismatch:\(context.debugDescription)")
    372             logger.error("\(context.codingPath)")
    373         } catch let error {       // rethrows
    374             logger.error("handleStateTransition: \(error.localizedDescription)")
    375         }
    376         throw WalletBackendError.walletCoreError(nil)       // TODO: error?
    377     }
    378 
    379     @MainActor private func handleNotification(_ anyCodable: AnyCodable?, _ message: String) throws {
    380         guard let anyPayload = anyCodable else {
    381             throw WalletBackendError.deserializationError
    382         }
    383         do {
    384             let jsonData = try JSONEncoder().encode(anyPayload)
    385             let payload = try JSONDecoder().decode(Payload.self, from: jsonData)
    386 
    387             switch payload.type {
    388                 case Notification.Name.Idle.rawValue:
    389 //                    symLog.log(message)
    390                     break
    391                 case Notification.Name.DatabaseMaintenance.rawValue:
    392                     symLog.log(message)
    393                     postNotification(.DatabaseMaintenance, userInfo: [NOTIFICATIONPAYLOAD: payload])
    394                     break
    395                 case Notification.Name.ExchangeStateTransition.rawValue:
    396                     symLog.log(message)
    397                     if let baseUrl = payload.exchangeBaseUrl,
    398                        let state = payload.newExchangeState {
    399                         Controller.shared.updateExchange(for: baseUrl, state: state)
    400                     }
    401                     break
    402                 case Notification.Name.RequestProgressError.rawValue:
    403                     symLog.log(message)
    404                     try handleRequestProgressError(jsonData)
    405                 case Notification.Name.RequestProgressPhase.rawValue:
    406                     symLog.log(message)
    407                     try handleRequestProgressPhase(jsonData)
    408                 case Notification.Name.TransactionStateTransition.rawValue:
    409                     symLog.log(message)
    410                     try handleStateTransition(jsonData)
    411                 case Notification.Name.PendingOperationProcessed.rawValue:
    412                     try handlePendingProcessed(payload)
    413                 case Notification.Name.BalanceChange.rawValue:
    414                     let now = Date()
    415                     symLog.log(message)
    416                     if !(payload.isInternal ?? false) {     // don't re-post internals
    417                         if let txID = payload.hintTransactionId {
    418                             if txID.contains("txn:refresh:") {
    419                                 break                       // don't re-post refresh
    420                             }
    421                         }
    422                         postNotification(.BalanceChange, userInfo: [NOTIFICATIONTIME: now])
    423                     }
    424                 case Notification.Name.BankAccountChange.rawValue:
    425                     symLog.log(message)
    426                     postNotification(.BankAccountChange)
    427                 case Notification.Name.ExchangeAdded.rawValue:
    428                     symLog.log(message)
    429                     postNotification(.ExchangeAdded)
    430                 case Notification.Name.ExchangeDeleted.rawValue:
    431                     symLog.log(message)
    432                     postNotification(.ExchangeDeleted)
    433                 case Notification.Name.ReserveNotYetFound.rawValue:
    434                     if let reservePub = payload.reservePub {
    435                         let userInfo = ["reservePub" : reservePub]
    436 //                        postNotification(.ReserveNotYetFound, userInfo: userInfo)   // TODO: remind User to confirm withdrawal
    437                     } // else { throw WalletBackendError.deserializationError }   shouldn't happen, but if it does just ignore it
    438 
    439                 case Notification.Name.ProposalAccepted.rawValue:               // "proposal-accepted":
    440                     symLog.log(message)
    441                     postNotification(.ProposalAccepted, userInfo: nil)
    442                 case Notification.Name.ProposalDownloaded.rawValue:             // "proposal-downloaded":
    443                     symLog.log(message)
    444                     postNotification(.ProposalDownloaded, userInfo: nil)
    445                 case Notification.Name.TaskObservabilityEvent.rawValue,
    446                      Notification.Name.RequestObservabilityEvent.rawValue:
    447                     if isObserving != 0 {
    448                         symLog.log(message)
    449                         let timestamp = TalerDater.dateString()
    450                         if let event = payload.event, let json = event.toJSON() {
    451                             let type = event["type"]?.value as? String
    452                             let eventID = event["id"]?.value as? String
    453                             if #available(iOS 16.0, *) {
    454                                 observe(json: json,
    455                                         type: type,
    456                                      eventID: eventID,
    457                                    timestamp: timestamp)
    458                             }
    459                         }
    460                     }
    461                     // TODO: remove these once wallet-core doesn't send them anymore
    462 //                case "refresh-started", "refresh-melted",
    463 //                     "refresh-revealed", "refresh-unwarranted":
    464 //                    break
    465                 default:
    466                     logger.error("NEW Notification: \(message)")        // this is a new notification I haven't seen before
    467                     break
    468             }
    469         } catch let error {
    470             logger.error("Error \(error) parsing notification: \(message)")
    471             postNotification(.GeneralError, userInfo: [NOTIFICATIONERROR: error])
    472         // TODO: if DevMode then should log into file for user
    473         }
    474     }
    475 
    476     /// wallet-core logs from its own thread, thus hop to the main actor before the console
    477     func handleLog(message: String) {
    478         guard isLogging else { return }         // don't flood the main queue when nobody looks
    479         DispatchQueue.main.async { [self] in
    480             handleLogM(message: message)
    481         }
    482     }
    483 
    484     @MainActor private func handleLogM(message: String) {
    485         if #available (iOS 16.0, *) {
    486             if isLogging {
    487                 let consoleManager = LCManager.shared
    488                 consoleManager.print(message)
    489             }
    490         }
    491     }
    492 
    493     @available(iOS 16.0, *)
    494     @MainActor func observe(json: String, type: String?, eventID: String?, timestamp: String) {
    495         let consoleManager = LCManager.shared
    496         if let type {
    497             if let eventID {
    498                 consoleManager.print("\(type)   \(eventID)")
    499             } else {
    500                 consoleManager.print(type)
    501             }
    502         }
    503         consoleManager.print("   \(timestamp)")
    504         if isObserving < 0 {
    505             consoleManager.print(json)
    506         }
    507         consoleManager.print("-   -   -")
    508     }
    509 
    510     /// A message we could not decode may still be the answer to a pending request.
    511     /// Fail that request, otherwise it would wait for an answer which never comes.
    512     private func failPendingRequest(_ messageData: Data, _ message: String) {
    513         guard let header = try? JSONDecoder().decode(ResponseHeader.self, from: messageData),
    514               header.type == "response" || header.type == "error",
    515               let requestId = header.id,
    516               let (timeSent, completion) = takeCompletion(requestId)
    517         else { return }
    518         logger.error("undecodable \(header.type, privacy: .public) for request \(requestId, privacy: .public)")
    519         completion(requestId, timeSent, message, nil, WalletCore.parseFailureError())
    520     }
    521 
    522     /// wallet-core calls this from its own thread, thus hop to the main actor
    523     func handleMessage(message: String) {
    524         DispatchQueue.main.async { [self] in
    525             handleMessageM(message: message)
    526         }
    527     }
    528 
    529     /// here not only responses, but also notifications from wallet-core will be received
    530     @MainActor private func handleMessageM(message: String) {
    531         do {
    532             guard let messageData = message.data(using: .utf8) else {
    533                 throw WalletBackendError.deserializationError
    534             }
    535             do {
    536                 let decoded = try JSONDecoder().decode(ResponseOrNotification.self, from: messageData)
    537                 switch decoded.type {
    538                     case "error":
    539                         symLog.log("\"id\":\(decoded.id ?? 0)  \(message)")
    540                         try handleError(decoded, message)
    541                     case "response":
    542 //                        symLog.log(message)
    543                         try handleResponse(decoded, message)
    544                     case "notification":
    545 //                        symLog.log(message)
    546                         try handleNotification(decoded.payload, message)
    547                     case "tunnelHttp":          // TODO: Handle tunnelHttp
    548                         symLog.log("Can't handle tunnelHttp: \(message)")    // TODO: .error
    549                         throw WalletBackendError.deserializationError
    550                     default:
    551                         symLog.log("Unknown response type: \(message)")    // TODO: .error
    552                         throw WalletBackendError.deserializationError
    553                 }
    554             } catch {   // e.g. a TalerErrorDetail from a remote server which doesn't decode
    555                 failPendingRequest(messageData, message)    // never leave a request hanging
    556                 throw error
    557             }
    558         } catch DecodingError.dataCorrupted(let context) {
    559             logger.error("\(context.debugDescription)")
    560         } catch DecodingError.keyNotFound(let key, let context) {
    561             logger.error("Key '\(key.stringValue)' not found:\(context.debugDescription)")
    562             logger.error("\(context.codingPath)")
    563         } catch DecodingError.valueNotFound(let value, let context) {
    564             logger.error("Value '\(value)' not found:\(context.debugDescription)")
    565             logger.error("\(context.codingPath)")
    566         } catch DecodingError.typeMismatch(let type, let context) {
    567             logger.error("Type '\(type)' mismatch:\(context.debugDescription)")
    568             logger.error("\(context.codingPath)")
    569         } catch let error {
    570             logger.error("\(error.localizedDescription)")
    571             // Anything that is not a DecodingError means we could not classify the
    572             // message at all (e.g. tunnelHttp, or an unknown "type"). A second
    573             // `catch` after this one would be unreachable, so notify from here.
    574             delegate?.walletBackendReceivedUnknownMessage(self, message: message)
    575         }
    576     }
    577     
    578     private func encodeAndSend(_ request: WalletBackendRequest, completionHandler: @escaping (UInt, Date, String?, Data?, TalerErrorDetail?) -> Void) {
    579         // Encode the request and send it to the backend.
    580         queue.async {
    581             let requestId = self.reserveRequestId()
    582             let sendTime = Date.now
    583             do {
    584                 let full = FullRequest(operation: request.operation, id: requestId, args: request.args)
    585 //          symLog.log(full)
    586                 let encoded = try JSONEncoder().encode(full)
    587                 guard let jsonString = String(data: encoded, encoding: .utf8) else { throw WalletBackendError.serializationError }
    588                     let args = try JSONEncoder().encode(request.args)
    589                     if let jsonArgs = String(data: args, encoding: .utf8) {
    590                         if request.operation == "getTransactionsV2" {
    591                             if self.logTransactions {
    592                                 self.logger.trace("🔴\"id\":\(requestId, privacy: .public) \(request.operation, privacy: .public)\(jsonArgs, privacy: .auto)")
    593                             }
    594                         } else {
    595                             self.logger.log("🔴\"id\":\(requestId, privacy: .public) \(request.operation, privacy: .public)\(jsonArgs, privacy: .auto)")
    596                         }
    597                     } else {    // should NEVER happen since the whole request was already successfully encoded and stringified
    598                         self.logger.log("🔴\"id\":\(requestId, privacy: .public) \(request.operation, privacy: .public) 🔴 Error: jsonArgs")
    599                     }
    600                 // register only after everything which can throw did succeed, but before
    601                 // sending - the answer may arrive before sendMessage() even returns
    602                 self.setCompletion(requestId, sendTime, completionHandler)
    603                 self.quickjs.sendMessage(message: jsonString)
    604 //              self.symLog.log(jsonString)
    605             } catch {       // call completion - nothing was registered, thus nobody else will
    606                 self.logger.error("\(error.localizedDescription)")
    607 //              self.symLog.log(error)
    608                 completionHandler(requestId, sendTime, nil, nil, WalletCore.serializeRequestError());
    609             }
    610         }
    611     }
    612 }
    613 // MARK: -  async / await function
    614 extension WalletCore {
    615     /// send async requests to wallet-core
    616     func sendFormattedRequest<T: WalletBackendFormattedRequest> (_ request: T, asJSON: Bool = false) async throws -> (T.Response, UInt) {
    617         let reqData = WalletBackendRequest(operation: request.operation,
    618                                            args: AnyEncodable(request.args()))
    619         return try await withCheckedThrowingContinuation { continuation in
    620             encodeAndSend(reqData) { [self] requestId, timeSent, message, result, error in
    621                 let timeUsed = Date.now - timeSent
    622                 let millisecs = timeUsed.milliseconds
    623                 if let error {
    624                     logger.error("Request \"id\":\(requestId, privacy: .public) failed after \(millisecs, privacy: .public) ms, error: \(error.code, privacy: .public)")
    625                 } else {
    626 #if DEBUG
    627                     if millisecs > (nativeDB ? 20 : 50) {
    628                         logger.info("Request \"id\":\(requestId, privacy: .public) took \(millisecs, privacy: .public) ms")
    629                     }
    630 #endif
    631                 }
    632                 var err: Error? = nil
    633                 if let json = result, error == nil {
    634                     do {
    635                         if asJSON {
    636                             if let message, let response = message as? T.Response {
    637                                 continuation.resume(returning: (response, requestId))
    638                             } else {
    639                                 continuation.resume(throwing: TransactionDecodingError.invalidStringValue)
    640                             }
    641                         } else {
    642                             let decoded = try JSONDecoder().decode(T.Response.self, from: json)
    643                             continuation.resume(returning: (decoded, requestId))
    644                         }
    645                         return
    646                     } catch DecodingError.dataCorrupted(let context) {
    647                         logger.error("\(context.debugDescription)")
    648                         err = DecodingError.dataCorrupted(context)
    649                     } catch DecodingError.keyNotFound(let key, let context) {
    650                         logger.error("Key '\(key.stringValue)' not found:\(context.debugDescription)")
    651                         logger.error("\(context.codingPath)")
    652                         err = DecodingError.keyNotFound(key, context)
    653                     } catch DecodingError.valueNotFound(let value, let context) {
    654                         logger.error("Value '\(value)' not found:\(context.debugDescription)")
    655                         logger.error("\(context.codingPath)")
    656                         err = DecodingError.valueNotFound(value, context)
    657                     } catch DecodingError.typeMismatch(let type, let context) {
    658                         logger.error("Type '\(type)' mismatch:\(context.debugDescription)")
    659                         logger.error("\(context.codingPath)")
    660                         err = DecodingError.typeMismatch(type, context)
    661                     } catch {       // rethrows
    662                         if let jsonString = String(data: json, encoding: .utf8) {
    663                             symLog.log(jsonString)       // TODO: .error
    664                         } else {
    665                             symLog.log(json)       // TODO: .error
    666                         }
    667                         err = error     // this will be thrown in continuation.resume(throwing:), otherwise keep nil
    668                     }
    669                 } else if let error {
    670                     // TODO: WALLET_CORE_REQUEST_CANCELLED
    671                     lastError = FullError(type: "error", operation: request.operation, id: requestId, error: error)
    672                     err = WalletBackendError.walletCoreError(error)
    673                 } else {        // both result and error are nil
    674                     lastError = nil
    675                 }
    676                 continuation.resume(throwing: err ?? TransactionDecodingError.invalidStringValue)
    677             }
    678         }
    679     }
    680 }