From 8f8b5ab315c85182df5803b888b62d307c639658 Mon Sep 17 00:00:00 2001
From: Sammy Cannillo <scannillo@paypal.com>
Date: Wed, 7 Aug 2024 15:35:28 -0500
Subject: [PATCH] WIP - Use while loop to prevent duplicate config GET requests
 & bool flag

Signed-off-by: Jax DesMarais-Leder <jdesmarais@paypal.com>
---
 Sources/BraintreeCore/BTAPIClient.swift       | 18 ++++-----
 Sources/BraintreeCore/BTHTTP.swift            | 13 +++++++
 .../ConfigurationCallbackStorage.swift        |  3 ++
 .../Configuration/ConfigurationLoader.swift   | 38 +++++++++++++++----
 4 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/Sources/BraintreeCore/BTAPIClient.swift b/Sources/BraintreeCore/BTAPIClient.swift
index 4479a94a05..92ddfce900 100644
--- a/Sources/BraintreeCore/BTAPIClient.swift
+++ b/Sources/BraintreeCore/BTAPIClient.swift
@@ -93,19 +93,15 @@ import Foundation
     /// cached on subsequent calls for better performance.
     @_documentation(visibility: private)
     public func fetchOrReturnRemoteConfiguration(_ completion: @escaping (BTConfiguration?, Error?) -> Void) {
-        configurationLoader.getConfig { [weak self] configuration, error in
-            guard let self else {
-                completion(nil, BTAPIClientError.deallocated)
-                return
-            }
-            
-            if let error {
+        // TODO: - Consider updating all feature clients to use async version of this method?
+        Task {
+            do {
+                let configuration = try await configurationLoader.getConfig()
+                setupHTTPCredentials(configuration)
+                completion(configuration, nil)
+            } catch {
                 completion(nil, error)
-                return
             }
-            
-            setupHTTPCredentials(configuration)
-            completion(configuration, nil)
         }
     }
     
diff --git a/Sources/BraintreeCore/BTHTTP.swift b/Sources/BraintreeCore/BTHTTP.swift
index ef72f275e9..b7df2773f1 100644
--- a/Sources/BraintreeCore/BTHTTP.swift
+++ b/Sources/BraintreeCore/BTHTTP.swift
@@ -77,6 +77,19 @@ class BTHTTP: NSObject, URLSessionTaskDelegate {
             completion(nil, nil, error)
         }
     }
+    
+    func get(_ path: String, configuration: BTConfiguration? = nil, parameters: Encodable? = nil) async throws -> (BTJSON, HTTPURLResponse) {
+        try await withCheckedThrowingContinuation { continuation in
+            get(path, configuration: configuration, parameters: parameters) { body, response, error in
+                if let error {
+                    continuation.resume(throwing: error)
+                } else if let body, let response {
+                    continuation.resume(returning: (body, response))
+                }
+            }
+            // TODO: - How do we want to handle case of nil body or response
+        }
+    }
 
     // TODO: - Remove when all POST bodies use Codable, instead of BTJSON/raw dictionaries
     func post(
diff --git a/Sources/BraintreeCore/Configuration/ConfigurationCallbackStorage.swift b/Sources/BraintreeCore/Configuration/ConfigurationCallbackStorage.swift
index a2ccbb430a..1b6b5ce132 100644
--- a/Sources/BraintreeCore/Configuration/ConfigurationCallbackStorage.swift
+++ b/Sources/BraintreeCore/Configuration/ConfigurationCallbackStorage.swift
@@ -1,8 +1,11 @@
 import Foundation
 
+// TODO: - Do we still need this class? It no-longer wraps an array to provide thread-safety
+
 /// Used to store, access, and manage an array of to-be-invoked `BTConfiguration` GET result callbacks
 class ConfigurationCallbackStorage {
     
+    // TODO: - Remove. Not an option to store array of completions.
     private var pendingCompletions: [(BTConfiguration?, Error?) -> Void] = []
     
     /// The number of completions that are waiting to be invoked
diff --git a/Sources/BraintreeCore/Configuration/ConfigurationLoader.swift b/Sources/BraintreeCore/Configuration/ConfigurationLoader.swift
index ecc15220f6..5b667a3b3f 100644
--- a/Sources/BraintreeCore/Configuration/ConfigurationLoader.swift
+++ b/Sources/BraintreeCore/Configuration/ConfigurationLoader.swift
@@ -8,7 +8,8 @@ class ConfigurationLoader {
     private let configurationCache = ConfigurationCache.shared
     private let http: BTHTTP
     private let pendingCompletions = ConfigurationCallbackStorage()
-    
+    private var isConfigCached = false // TODO: - Rename; should this bool live here?
+
     // MARK: - Intitializer
     
     init(http: BTHTTP) {
@@ -69,17 +70,38 @@ class ConfigurationLoader {
             }
         }
     }
-    
+        
     func getConfig() async throws -> BTConfiguration {
-        try await withCheckedThrowingContinuation { continuation in
-            getConfig { configuration, error in
-                if let error {
-                    continuation.resume(throwing: error)
-                } else if let configuration {
-                    continuation.resume(returning: configuration)
+        if let cachedConfig = try? configurationCache.getFromCache(authorization: http.authorization.bearer) {
+            isConfigCached = true
+            return cachedConfig
+        }
+     
+        while !isConfigCached {
+            print("While loop body")
+            
+            do {
+                print("🤞GET request made")
+                let (body, response) = try await http.get(configPath, parameters: BTConfigurationRequest())
+                
+                if response.statusCode != 200 { // || body == nil {
+                    throw BTAPIClientError.configurationUnavailable
+                } else {
+                    let configuration = BTConfiguration(json: body)
+                    
+                    try? configurationCache.putInCache(authorization: http.authorization.bearer, configuration: configuration)
+                    
+                    NotificationCenter.default.post(name: Notification.Name("ConfigGet"), object: configuration)
+                    isConfigCached = true
+
+                    return configuration
                 }
+            } catch {
+                throw error
             }
         }
+        print("Exited while loop")
+        throw BTAPIClientError.configurationUnavailable
     }
     
     // MARK: - Private Methods