Improved the GetUserUseCase use case by moving some logic to this use case.

Libraries/Sources/UseCases/Users/GetUserUseCase.swift

@@ -10,22 +10,76 @@ import APIService
 import DataModels
 import DependencyInjection
 import Dependencies
+import KeychainStorage
 
-public struct GetUserUseCase {
+public actor GetUserUseCase {
     
-    // MARK: Dependencies
+    // MARK: Properties
     
-    @Dependency(\.apiService) private var apiService
+    private let apiService: APIService
+
+    private var account: Account?
     
     // MARK: Initialisers
     
-    public init() {}
+    public init(
+        apiService: APIService,
+        account: Account?
+    ) {
+        self.apiService = apiService
+        self.account = account
+    }
     
     // MARK: Functions
     
+    public func callAsFunction() async throws -> User {
+        guard let account else { throw GetUserError .accountNotFound }
+        
+        return try await getUser(
+            username: account.username,
+            password: account.password
+        )
+    }
+    
     public func callAsFunction(
         username: String,
         password: String
+    ) async throws -> User {
+        let user = try await getUser(
+            username: username,
+            password: password
+        )
+        
+        account = .init(
+            username: username,
+            password: password
+        )
+        
+        return user
+    }
+
+}
+
+// MARK: - Initialisers
+
+public extension GetUserUseCase {
+    init() {
+        @Dependency(\.apiService) var apiService
+        @KeychainStorage(key: .KeychainStorage.account) var account: Account?
+        
+        self.init(
+            apiService: apiService,
+            account: account
+        )
+    }
+}
+
+// MARK: - Helpers
+
+private extension GetUserUseCase {
+    func getUser(
+        username: String,
+        password: String
     ) async throws -> User {
         let me = try await apiService.getUser(
             credentials: .init(
@@ -46,5 +100,10 @@ public struct GetUserUseCase {
             )
         )
     }
-
+}
+
+// MARK: - Errors
+
+public enum GetUserError: Error {
+    case accountNotFound
 }