Fixes #34 [BUG] TooManyProviderTokenUpdates (#35)

* requests will cache jwt and reuse until timeout

* Resolves comments; Implements in struct instead of class

* Implement token as a computed property

Author: itcohorts

Sources/APNSwift/APNSwiftBearerToken.swift

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the APNSwift open source project
+//
+// Copyright (c) 2019 the APNSwift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of APNSwift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+
+public struct APNSwiftBearerToken {
+    let configuration: APNSwiftConfiguration
+    let timeout: TimeInterval
+    var createdAt: TimeInterval?
+    private var cachedToken: String?
+    
+    public init(configuration: APNSwiftConfiguration, timeout: TimeInterval) {
+        self.configuration = configuration
+        self.timeout = timeout
+    }
+    
+    public var token: String? {
+        mutating get {
+            let now = Date().timeIntervalSince1970
+            guard let existingToken = cachedToken, let timeCreated = createdAt, (now - timeCreated) <= timeout else {
+                cachedToken = try? createToken()
+                createdAt = now
+                return cachedToken
+            }
+            return existingToken
+        }
+    }
+    
+    private func createToken() throws -> String {
+        let jwt = APNSwiftJWT(keyID: configuration.keyIdentifier, teamID: configuration.teamIdentifier, issueDate: Date(), expireDuration: timeout)
+        var token: String
+        let digestValues = try jwt.getDigest()
+        var signature = try configuration.signer.sign(digest: digestValues.fixedDigest)
+        guard let data = signature.readData(length: signature.readableBytes) else {
+            throw APNSwiftError.SigningError.invalidSignatureData
+        }
+        token = digestValues.digest + "." + data.base64EncodedURLString()
+        return token
+    }
+}

Sources/APNSwift/APNSwiftConnection.swift

@@ -76,6 +76,7 @@ public final class APNSwiftConnection {
     /**
      APNSwiftConnection send method. Sends a notification to the desired deviceToken.
      - Parameter notification: the notification meta data and alert to send.
+     - Parameter bearerToken: the bearer token to authenitcate our request
      - Parameter deviceToken: device token to send alert to.
      - Parameter encoder: customer JSON encoder if needed.
      - Parameter expiration: a date that the notificaiton expires.
@@ -89,16 +90,17 @@ public final class APNSwiftConnection {
      ```
      let apns = APNSwiftConnection.connect()
      let expiry = Date().addingTimeInterval(5)
-     try apns.send(notification, to: "b27a07be2092c7fbb02ab5f62f3135c615e18acc0ddf39a30ffde34d41665276", with: JSONEncoder(), expiration: expiry, priority: 10, collapseIdentifier: "huro2").wait()
+     let bearerToken = APNSwiftBearerToken(configuration: apnsConfig, timeout: 50.0)
+     try apns.send(notification, bearerToken: bearerToken,to: "b27a07be2092c7fbb02ab5f62f3135c615e18acc0ddf39a30ffde34d41665276", with: JSONEncoder(), expiration: expiry, priority: 10, collapseIdentifier: "huro2").wait()
      ```
      */
-    public func send<Notification>(_ notification: Notification, to deviceToken: String, with encoder: JSONEncoder = JSONEncoder(), expiration: Date? = nil, priority: Int? = nil, collapseIdentifier: String? = nil, topic: String? = nil) -> EventLoopFuture<Void>
+    public func send<Notification>(_ notification: Notification, bearerToken: APNSwiftBearerToken, to deviceToken: String, with encoder: JSONEncoder = JSONEncoder(), expiration: Date? = nil, priority: Int? = nil, collapseIdentifier: String? = nil, topic: String? = nil) -> EventLoopFuture<Void>
         where Notification: APNSwiftNotification {
             let streamPromise = channel.eventLoop.makePromise(of: Channel.self)
             multiplexer.createStreamChannel(promise: streamPromise) { channel, streamID in
                 let handlers: [ChannelHandler] = [
                     HTTP2ToHTTP1ClientCodec(streamID: streamID, httpProtocol: .https),
-                    APNSwiftRequestEncoder<Notification>(deviceToken: deviceToken, configuration: self.configuration, expiration: expiration, priority: priority, collapseIdentifier: collapseIdentifier),
+                    APNSwiftRequestEncoder<Notification>(deviceToken: deviceToken, configuration: self.configuration, bearerToken: bearerToken, expiration: expiration, priority: priority, collapseIdentifier: collapseIdentifier),
                     APNSwiftResponseDecoder(),
                     APNSwiftStreamHandler(),
                 ]

Sources/APNSwift/APNSwiftRequestEncoder.swift

@@ -27,14 +27,17 @@ internal final class APNSwiftRequestEncoder<Notification>: ChannelOutboundHandle
     typealias OutboundOut = HTTPClientRequestPart
 
     let configuration: APNSwiftConfiguration
+    var bearerToken: APNSwiftBearerToken
     let deviceToken: String
     let priority: Int?
     let expiration: Date?
     let collapseIdentifier: String?
     let topic: String?
-
-    init(deviceToken: String, configuration: APNSwiftConfiguration, expiration: Date?, priority: Int?, collapseIdentifier: String?, topic: String? = nil) {
+    
+    
+    init(deviceToken: String, configuration: APNSwiftConfiguration, bearerToken: APNSwiftBearerToken, expiration: Date?, priority: Int?, collapseIdentifier: String?, topic: String? = nil) {
         self.configuration = configuration
+        self.bearerToken = bearerToken
         self.deviceToken = deviceToken
         self.expiration = expiration
         self.priority = priority
@@ -65,18 +68,8 @@ internal final class APNSwiftRequestEncoder<Notification>: ChannelOutboundHandle
             reqHead.headers.add(name: "apns-collapse-id", value: collapseId)
         }
         reqHead.headers.add(name: "host", value: configuration.url.host!)
-        let jwt = APNSwiftJWT(keyID: configuration.keyIdentifier, teamID: configuration.teamIdentifier, issueDate: Date(), expireDuration: 60 * 60)
-        var token: String
-        do {
-            let digestValues = try jwt.getDigest()
-            let signature = try configuration.signer.sign(digest: digestValues.fixedDigest)
-            guard let data = signature.getData(at: 0, length: signature.readableBytes) else {
-                throw APNSwiftError.SigningError.invalidSignatureData
-            }
-            token = digestValues.digest + "." + data.base64EncodedURLString()
-        } catch {
-            promise?.fail(error)
-            context.close(promise: nil)
+        guard let token = bearerToken.token else {
+            promise?.fail(APNSwiftError.SigningError.invalidSignatureData)
             return
         }
         reqHead.headers.add(name: "authorization", value: "bearer \(token)")

Sources/APNSwiftExample/main.swift

@@ -52,10 +52,16 @@ let aps = APNSwiftPayload(alert: alert, badge: 0, sound: .critical(apsSound), ha
 let temp = try! JSONEncoder().encode(aps)
 let string = String(bytes: temp, encoding: .utf8)
 let notification = AcmeNotification(acme2: ["bang", "whiz"], aps: aps)
+let token = APNSwiftBearerToken(configuration: apnsConfig, timeout: 50.0)
 
 do {
     let expiry = Date().addingTimeInterval(5)
-    try apns.send(notification, to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token, to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token, to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token,  to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token,  to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token,  to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
+    try apns.send(notification, bearerToken: token,  to: "b693f99efa926bcf9977adae75bc88a97988365f49e4c6abf94aa659a4d87a6b", expiration: expiry, priority: 10).wait()
 } catch {
     print(error)
 }