Prevent more than one OPML import from being run at the same time.

Frameworks/Account/Account.swift

@@ -36,9 +36,25 @@ public enum AccountType: Int {
 	// TODO: more
 }
 
-public enum AccountError: Error {
+public enum AccountError: LocalizedError {
+	
 	case createErrorNotFound
 	case createErrorAlreadySubscribed
+	case opmlImportInProgress
+	
+	public var errorDescription: String? {
+		switch self {
+		case .opmlImportInProgress:
+			return NSLocalizedString("An OPML import for this account is already running.", comment: "Import running")
+		default:
+			return NSLocalizedString("An unknown error occurred.", comment: "Unknown error")
+		}
+	}
+	
+	public var recoverySuggestion: String? {
+		return NSLocalizedString("Please try again later.", comment: "Try later")
+	}
+	
 }
 
 public final class Account: DisplayNameProvider, UnreadCountProvider, Container, Hashable {
@@ -299,6 +315,12 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 	}
 	
 	public func importOPML(_ opmlFile: URL, completion: @escaping (Result<Void, Error>) -> Void) {
+		
+		guard !delegate.opmlImportInProgress else {
+			completion(.failure(AccountError.opmlImportInProgress))
+			return
+		}
+		
 		delegate.importOPML(for: self, opmlFile: opmlFile) { [weak self] result in
 			switch result {
 			case .success:
@@ -312,6 +334,7 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 				completion(.failure(error))
 			}
 		}
+		
 	}
 	
 	public func markArticles(_ articles: Set<Article>, statusKey: ArticleStatus.Key, flag: Bool) -> Set<Article>? {

Frameworks/Account/AccountDelegate.swift

@@ -14,6 +14,8 @@ protocol AccountDelegate {
 
 	// Local account does not; some synced accounts might.
 	var supportsSubFolders: Bool { get }
+	var opmlImportInProgress: Bool { get }
+	
 	var server: String? { get }
 	var credentials: Credentials? { get set }
 	var accountMetadata: AccountMetadata? { get set }

Frameworks/Account/Feedbin/FeedbinAccountDelegate.swift

@@ -32,6 +32,7 @@ final class FeedbinAccountDelegate: AccountDelegate {
 
 	let supportsSubFolders = false
 	let server: String? = "api.feedbin.com"
+	var opmlImportInProgress = false
 	
 	var credentials: Credentials? {
 		didSet {
@@ -201,6 +202,7 @@ final class FeedbinAccountDelegate: AccountDelegate {
 		}
 		
 		os_log(.debug, log: log, "Begin importing OPML...")
+		opmlImportInProgress = true
 		
 		caller.importOPML(opmlData: opmlData) { [weak self] result in
 			switch result {
@@ -208,6 +210,7 @@ final class FeedbinAccountDelegate: AccountDelegate {
 				if importResult.complete {
 					guard let self = self else { return }
 					os_log(.debug, log: self.log, "Import OPML done.")
+					self.opmlImportInProgress = false
 					DispatchQueue.main.async {
 						completion(.success(()))
 					}
@@ -217,6 +220,7 @@ final class FeedbinAccountDelegate: AccountDelegate {
 			case .failure(let error):
 				guard let self = self else { return }
 				os_log(.debug, log: self.log, "Import OPML failed.")
+				self.opmlImportInProgress = false
 				DispatchQueue.main.async {
 					completion(.failure(error))
 				}
@@ -225,41 +229,6 @@ final class FeedbinAccountDelegate: AccountDelegate {
 		
 	}
 	
-	private func checkImportResult(opmlImportResultID: Int, completion: @escaping (Result<Void, Error>) -> Void) {
-		
-		DispatchQueue.main.async {
-			
-			Timer.scheduledTimer(withTimeInterval: 15, repeats: true) { [weak self] timer in
-				
-				guard let self = self else { return }
-				
-				os_log(.debug, log: self.log, "Checking status of OPML import...")
-				
-				self.caller.retrieveOPMLImportResult(importID: opmlImportResultID) { result in
-					switch result {
-					case .success(let importResult):
-						if let result = importResult, result.complete {
-							os_log(.debug, log: self.log, "Checking status of OPML import successfully completed.")
-							timer.invalidate()
-							DispatchQueue.main.async {
-								completion(.success(()))
-							}
-						}
-					case .failure(let error):
-						os_log(.debug, log: self.log, "Import OPML check failed.")
-						timer.invalidate()
-						DispatchQueue.main.async {
-							completion(.failure(error))
-						}
-					}
-				}
-				
-			}
-			
-		}
-
-	}
-	
 	func renameFolder(for account: Account, with folder: Folder, to name: String, completion: @escaping (Result<Void, Error>) -> Void) {
 		
 		caller.renameTag(oldName: folder.name ?? "", newName: name) { result in
@@ -546,6 +515,43 @@ private extension FeedbinAccountDelegate {
 		
 	}
 	
+	func checkImportResult(opmlImportResultID: Int, completion: @escaping (Result<Void, Error>) -> Void) {
+		
+		DispatchQueue.main.async {
+			
+			Timer.scheduledTimer(withTimeInterval: 15, repeats: true) { [weak self] timer in
+				
+				guard let self = self else { return }
+				
+				os_log(.debug, log: self.log, "Checking status of OPML import...")
+				
+				self.caller.retrieveOPMLImportResult(importID: opmlImportResultID) { result in
+					switch result {
+					case .success(let importResult):
+						if let result = importResult, result.complete {
+							os_log(.debug, log: self.log, "Checking status of OPML import successfully completed.")
+							timer.invalidate()
+							self.opmlImportInProgress = false
+							DispatchQueue.main.async {
+								completion(.success(()))
+							}
+						}
+					case .failure(let error):
+						os_log(.debug, log: self.log, "Import OPML check failed.")
+						timer.invalidate()
+						self.opmlImportInProgress = false
+						DispatchQueue.main.async {
+							completion(.failure(error))
+						}
+					}
+				}
+				
+			}
+			
+		}
+		
+	}
+	
 	func syncFolders(_ account: Account, _ tags: [FeedbinTag]?) {
 		
 		guard let tags = tags else { return }

Frameworks/Account/LocalAccount/LocalAccountDelegate.swift

@@ -18,6 +18,8 @@ public enum LocalAccountDelegateError: String, Error {
 final class LocalAccountDelegate: AccountDelegate {
 	
 	let supportsSubFolders = false
+	let opmlImportInProgress = false
+	
 	let server: String? = nil
 	var credentials: Credentials?
 	var accountMetadata: AccountMetadata?