feat(Network): Adds retry mechanism for the failed networking requests

Example/Shared/Networking/GetPlacements.swift

@@ -22,7 +22,7 @@ class GetPlacements {
         guard let url = URL(string: "\(root)/placements.json") else { return nil }
         let session = URLSession.shared
         let publisher = session.dataTaskPublisher(for: url)
-            .tryMap() { element -> Data in
+            .tryMap { element -> Data in
                 guard let httpResponse = element.response as? HTTPURLResponse,
                       httpResponse.statusCode == 200 else {
                     throw URLError(.badServerResponse)

Pod/Classes/Common/Model/Constants.swift

@@ -6,6 +6,12 @@
 //
 
 struct Constants {
+    /// Number of retries for each network request before it fails
+    static let numberOfRetries = 5
+
+    /// The delay between each request when retrying
+    static let retryDelay: TimeInterval = 1
+
     static let defaultClickThresholdInSecs = 5
     static let defaultTestMode = false
     static let defaultParentalGate = false

Pod/Classes/Network/DI/NetworkModule.swift

@@ -25,7 +25,10 @@ class NetworkModule: DependencyModule {
                                                             cont.resolve() as MoyaLoggerPlugin])
         }
         container.single(AwesomeAdsApiDataSourceType.self) { cont, _ in
-            MoyaAwesomeAdsApiDataSource(provider: cont.resolve(), environment: cont.resolve())
+            MoyaAwesomeAdsApiDataSource(provider: cont.resolve(),
+                                        environment: cont.resolve(),
+                                        retryDelay: Constants.retryDelay,
+                                        logger: cont.resolve(param: MoyaAwesomeAdsApiDataSource.self) as LoggerType)
         }
         container.single(NetworkDataSourceType.self) { _, _ in
             AFNetworkDataSource()

Pod/Classes/Network/DataSources/MoyaAwesomeAdsApiDataSource.swift

@@ -11,10 +11,14 @@ class MoyaAwesomeAdsApiDataSource: AwesomeAdsApiDataSourceType {
 
     private let provider: MoyaProvider<AwesomeAdsTarget>
     private let environment: Environment
+    private let retryDelay: TimeInterval
+    private let logger: LoggerType
 
-    init(provider: MoyaProvider<AwesomeAdsTarget>, environment: Environment) {
+    init(provider: MoyaProvider<AwesomeAdsTarget>, environment: Environment, retryDelay: TimeInterval, logger: LoggerType) {
         self.provider = provider
         self.environment = environment
+        self.retryDelay = retryDelay
+        self.logger = logger
     }
 
     func getAd(placementId: Int, query: QueryBundle, completion: @escaping OnResult<Ad>) {
@@ -107,18 +111,39 @@ class MoyaAwesomeAdsApiDataSource: AwesomeAdsApiDataSourceType {
     }
 
     private func responseHandler(target: AwesomeAdsTarget, completion: OnResult<Void>?) {
-        provider.request(target) { result in
-            switch result {
-            case .success(let response):
-                do {
-                    _ = try response.filterSuccessfulStatusCodes()
-                    completion?(Result.success(Void()))
-                } catch let error {
-                    completion?(Result.failure(error))
+        var retries = 0
+        let delay = retryDelay
+        let innerLogger = logger
+
+        func innerRequest() {
+            provider.request(target) { result in
+                switch result {
+                case .success(let response):
+                    do {
+                        _ = try response.filterSuccessfulStatusCodes()
+                        completion?(Result.success(Void()))
+                    } catch let error {
+                        // If the server responds with a 4xx or 5xx error
+                        completion?(Result.failure(error))
+                    }
+                case .failure(let error):
+                    // This means there was a network failure
+                    // - either the request wasn't sent (connectivity),
+                    // - or no response was received (server timed out)
+                    if retries < Constants.numberOfRetries {
+                        innerLogger.error("Network failure, retrying again", error: error)
+                        retries += 1
+                        DispatchQueue.global().asyncAfter(deadline: .now() + delay) {
+                            innerRequest()
+                        }
+                    } else {
+                        innerLogger.error("Number of retries reached", error: error)
+                        completion?(Result.failure(error))
+                    }
                 }
-            case .failure(let error):
-                completion?(Result.failure(error))
             }
         }
+
+        innerRequest()
     }
 }

Pod/Classes/UI/Managed/SAManagedAdViewController.swift

@@ -66,7 +66,7 @@ import WebKit
 
     private func configureCloseButton() {
 
-        if (closeButton != nil) {
+        if closeButton != nil {
             closeButton?.removeFromSuperview()
             closeButton = nil
         }
@@ -161,7 +161,7 @@ extension SAManagedAdViewController: AdViewJavaScriptBridge {
     func onEvent(event: AdEvent) {
         callback?(placementId, event)
 
-        if (event == .adShown && config.closeButtonState == .visibleWithDelay) {
+        if event == .adShown && config.closeButtonState == .visibleWithDelay {
             showCloseButtonAfterDelay()
         }