Prevent adding duplicate word anywhere

Resources/iOSSupport/Localization/en.lproj/Localizable.strings

@@ -80,3 +80,5 @@ more_menu = "More menu";
 memorize_words = "Memorize words";
 next_word = "Next word";
 previous_word = "Previous word";
+
+duplicate_word = "Duplicate word.";

Resources/iOSSupport/Localization/ko.lproj/Localizable.strings

@@ -79,3 +79,5 @@ more_menu = "메뉴 더보기";
 memorize_words = "단어 암기";
 next_word = "다음 단어";
 previous_word = "이전 단어";
+
+duplicate_word = "중복 단어입니다.";

Sources/Domain/Interfaces/UseCases/Word/WordUseCaseProtocol.swift

@@ -44,4 +44,9 @@ public protocol WordUseCaseProtocol {
 
     func getCurrentUnmemorizedWord() -> Single<Word>
 
+    /// `word` 파라미터로 전달된 단어가 이미 저장되어 있는 단어인지 검사합니다.
+    ///
+    /// - Returns: 반환된 Sequence 는 `ture` or `false` 값을 가진 next 이벤트만 방출됩니다. error 이벤트는 방출되지 않습니다.
+    func isWordDuplicated(_ word: String) -> Single<Bool>
+
 }

Sources/Domain/UseCases/WordUseCase.swift

@@ -99,6 +99,15 @@ public final class WordUseCase: WordUseCaseProtocol {
     }
 
     public func updateWord(by uuid: UUID, to newWord: Word) -> RxSwift.Single<Void> {
+        guard let originWord = wordRepository.getWord(by: uuid) else {
+            return .error(WordUseCaseError.retrieveFailed(reason: .uuidInvaild(uuid: uuid)))
+        }
+
+        let allWords = self.wordRepository.getAllWords()
+        if (originWord.word != newWord.word) && allWords.contains(where: { $0.word.lowercased() == newWord.word.lowercased() }) {
+            return .error(WordUseCaseError.saveFailed(reason: .duplicatedWord(word: newWord.word)))
+        }
+
         return .create { single in
             let updateTarget: Word = .init(
                 uuid: uuid,
@@ -180,4 +189,13 @@ public final class WordUseCase: WordUseCaseProtocol {
         return .just(currentWord)
     }
 
+    public func isWordDuplicated(_ word: String) -> Single<Bool> {
+        let allWords = self.wordRepository.getAllWords()
+        if allWords.contains(where: { $0.word.lowercased() == word.lowercased() }) {
+            return .just(true)
+        } else {
+            return .just(false)
+        }
+    }
+
 }

Sources/DomainTesting/WordUseCaseFake.swift

@@ -15,13 +15,18 @@ import Utility
 
 public final class WordUseCaseFake: WordUseCaseProtocol {
 
+    /// Fake 객체 구현을 위해 사용한 인메모리 단어 저장소
     public var _wordList: [Domain.Word] = []
 
     public var _unmemorizedWordList: UnmemorizedWordListRepositorySpy = .init()
 
     public init() {}
 
     public func addNewWord(_ word: Domain.Word) -> Single<Void> {
+        if _wordList.contains(where: { $0.word.lowercased() == word.word.lowercased() }) {
+            return .error(WordUseCaseError.saveFailed(reason: .duplicatedWord(word: word.word)))
+        }
+
         _wordList.append(word)
         _unmemorizedWordList.addWord(word)
         return .just(())
@@ -57,10 +62,33 @@ public final class WordUseCaseFake: WordUseCaseProtocol {
     }
 
     public func updateWord(by uuid: UUID, to newWord: Domain.Word) -> Single<Void> {
-        if let index = _wordList.firstIndex(where: { $0.uuid == uuid }) {
-            _wordList[index] = newWord
+        guard let index = _wordList.firstIndex(where: { $0.uuid == uuid }) else {
+            return .error(WordUseCaseError.retrieveFailed(reason: .uuidInvaild(uuid: uuid)))
+        }
+
+        if (newWord.word != _wordList[index].word) && _wordList.contains(where: { $0.word.lowercased() == newWord.word.lowercased() }) {
+            return .error(WordUseCaseError.saveFailed(reason: .duplicatedWord(word: newWord.word)))
+        }
+
+        let updateTarget: Word = .init(
+            uuid: uuid,
+            word: newWord.word,
+            memorizedState: newWord.memorizedState
+        )
+
+        if _unmemorizedWordList.contains(where: { $0.uuid == updateTarget.uuid }) {
+            switch updateTarget.memorizedState {
+            case .memorized:
+                _unmemorizedWordList.deleteWord(by: uuid)
+            case .memorizing:
+                _unmemorizedWordList.replaceWord(where: uuid, with: updateTarget)
+            }
+        } else if updateTarget.memorizedState == .memorizing {
+            _unmemorizedWordList.addWord(updateTarget)
         }
-        _unmemorizedWordList.replaceWord(where: uuid, with: newWord)
+
+        _wordList[index] = updateTarget
+
         return .just(())
     }
 
@@ -97,4 +125,12 @@ public final class WordUseCaseFake: WordUseCaseProtocol {
         return .just(currentWord)
     }
 
+    public func isWordDuplicated(_ word: String) -> Single<Bool> {
+        if _wordList.contains(where: { $0.word.lowercased() == word.lowercased() }) {
+            return .just(true)
+        } else {
+            return .just(false)
+        }
+    }
+
 }

Sources/iOSScenes/WordAddition/WordAdditionViewController.swift

@@ -31,6 +31,13 @@ final class WordAdditionViewController: RxBaseViewController, WordAdditionViewCo
         $0.borderStyle = .roundedRect
     }
 
+    let duplicatedWordAlertLabel: UILabel = .init().then {
+        $0.text = WCString.duplicate_word
+        $0.textColor = .systemRed
+        $0.adjustsFontForContentSizeCategory = true
+        $0.font = .preferredFont(forTextStyle: .footnote)
+    }
+
     lazy var cancelBarButton: UIBarButtonItem = .init(systemItem: .cancel)
 
     lazy var doneBarButton: UIBarButtonItem = .init(systemItem: .done).then {
@@ -55,11 +62,17 @@ final class WordAdditionViewController: RxBaseViewController, WordAdditionViewCo
 
     func setupSubviews() {
         self.view.addSubview(wordTextField)
+        self.view.addSubview(duplicatedWordAlertLabel)
 
         wordTextField.snp.makeConstraints { make in
             make.top.equalTo(self.view.safeAreaLayoutGuide).offset(10)
             make.leading.trailing.equalTo(self.view.safeAreaLayoutGuide).inset(20)
         }
+
+        duplicatedWordAlertLabel.snp.makeConstraints { make in
+            make.leading.trailing.equalTo(self.view.safeAreaLayoutGuide).inset(22)
+            make.top.equalTo(wordTextField.snp.bottom).offset(10)
+        }
     }
 
     func setupNavigationBar() {
@@ -75,7 +88,7 @@ final class WordAdditionViewController: RxBaseViewController, WordAdditionViewCo
             return
         }
         let input: WordAdditionViewModel.Input = .init(
-            wordText: wordTextField.rx.text.orEmpty.asDriver(),
+            wordText: wordTextField.rx.text.orEmpty.asDriver().distinctUntilChanged(),
             saveAttempt: doneBarButton.rx.tap.asSignal(),
             dismissAttempt: Signal.merge(
                 cancelBarButton.rx.tap.asSignal(),
@@ -89,8 +102,6 @@ final class WordAdditionViewController: RxBaseViewController, WordAdditionViewCo
                 .emit(with: self, onNext: { owner, _ in
                     owner.delegate?.viewControllerMustBeDismissed(owner)
                 }),
-            output.wordTextIsNotEmpty
-                .drive(doneBarButton.rx.isEnabled),
             output.reconfirmDismiss
                 .emit(with: self, onNext: { owner, _ in
                     owner.presentDismissActionSheet {
@@ -101,6 +112,15 @@ final class WordAdditionViewController: RxBaseViewController, WordAdditionViewCo
                 .emit(with: self, onNext: { owner, _ in
                     owner.delegate?.viewControllerMustBeDismissed(owner)
                 }),
+            output.enteredWordIsDuplicated
+                .distinctUntilChanged()
+                .map { !$0 }
+                .drive(duplicatedWordAlertLabel.rx.isHidden),
+            Driver.zip([
+                output.wordTextIsNotEmpty,
+                output.enteredWordIsDuplicated,
+            ]).map { $0[0] && !$0[1] }
+                .drive(doneBarButton.rx.isEnabled),
         ]
             .forEach { $0.disposed(by: disposeBag) }
     }

Sources/iOSScenes/WordAddition/WordAdditionViewModel.swift

@@ -22,7 +22,7 @@ final class WordAdditionViewModel: ViewModelType {
     }
 
     func transform(input: Input) -> Output {
-        let initialWordText = ""
+        let initialWordText = "" // 새 단어를 추가할때는 초기 단어가 없으므로
 
         let hasChanges = input.wordText.map { $0 != initialWordText }
 
@@ -53,11 +53,18 @@ final class WordAdditionViewModel: ViewModelType {
             .mapToVoid()
             .asSignalOnErrorJustComplete()
 
+        let enteredWordIsDuplicated = input.wordText
+            .flatMapLatest { word in
+                return self.wordUseCase.isWordDuplicated(word)
+                    .asDriverOnErrorJustComplete()
+            }
+
         return .init(
             saveComplete: saveComplete,
             wordTextIsNotEmpty: wordTextIsNotEmpty,
             reconfirmDismiss: reconfirmDismiss,
-            dismissComplete: dismissComplete
+            dismissComplete: dismissComplete,
+            enteredWordIsDuplicated: enteredWordIsDuplicated
         )
     }
 
@@ -81,10 +88,13 @@ extension WordAdditionViewModel {
 
         let wordTextIsNotEmpty: Driver<Bool>
 
+        /// Dismiss 해야하는지 재확인이 필요할때 next 이벤트가 방출됩니다.
         let reconfirmDismiss: Signal<Void>
 
         let dismissComplete: Signal<Void>
 
+        /// 입력되어 있는 단어가 중복된 단어인지 여부
+        var enteredWordIsDuplicated: Driver<Bool>
     }
 
 }

Sources/iOSScenes/WordDetail/WordDetailReactor.swift

@@ -17,21 +17,45 @@ final class WordDetailReactor: Reactor {
         case viewDidLoad
         case beginEditing
         case doneEditing
-        case editWord(String)
+
+        /// 현재 입력된 단어
+        case enteredWord(String)
+
         case changeMemorizedState(MemorizedState)
     }
 
     enum Mutation {
         case updateWord(Word)
         case markAsEditing
+
+        /// 현재 입력된 단어를 중복된 단어로 표시할지 결정하는 Mutation
+        case setDuplicated(Bool)
+
+        /// 현재 입력된 단어의 비어있음 상태를 결정하는 Mutation
+        case setEmpty(Bool)
     }
 
     struct State {
+
+        /// 현재 입력된 단어
         var word: Word
+
+        /// 현재 화면에서 변경사항이 발생했는지 여부를 나타내는 값
         var hasChanges: Bool
+
+        /// 입력되어 있는 단어가 중복된 단어인지 여부를 나타내는 값
+        var enteredWordIsDuplicated: Bool
+
+        /// 현재 입력된 단어가 비어있는지 여부를 나타내는 값
+        var enteredWordIsEmpty: Bool
     }
 
-    var initialState: State = State(word: .empty, hasChanges: false)
+    var initialState: State = State(
+        word: .empty,
+        hasChanges: false,
+        enteredWordIsDuplicated: false,
+        enteredWordIsEmpty: false // Detail 화면에서는 항상 초기 단어가 있으므로
+    )
 
     /// 현재 보여지고 있는 단어의 UUID 입니다.
     let uuid: UUID
@@ -73,10 +97,24 @@ final class WordDetailReactor: Reactor {
                 .asObservable()
                 .flatMap { _ -> Observable<Mutation> in return .empty() }
 
-        case .editWord(let word):
-            self.currentState.word.word = word
+        case .enteredWord(let enteredWord):
+            let setDuplicatedMutation = wordUseCase.isWordDuplicated(enteredWord)
+                .asObservable()
+                .map { [weak self] isWordDuplicated in
+                    if isWordDuplicated && (enteredWord != self?.originWord) { // 원래 단어와 달라야 중복이므로
+                        return Mutation.setDuplicated(true)
+                    } else {
+                        return Mutation.setDuplicated(false)
+                    }
+                }
+
+            self.currentState.word.word = enteredWord
 
-            return .just(.updateWord(self.currentState.word))
+            return .merge([
+                .just(.updateWord(self.currentState.word)),
+                setDuplicatedMutation,
+                .just(.setEmpty(enteredWord.isEmpty)),
+            ])
 
         case .changeMemorizedState(let state):
             self.currentState.word.memorizedState = state
@@ -96,6 +134,10 @@ final class WordDetailReactor: Reactor {
             state.word = word
         case .markAsEditing:
             state.hasChanges = true
+        case .setDuplicated(let enteredWordIsDuplicated):
+            state.enteredWordIsDuplicated = enteredWordIsDuplicated
+        case .setEmpty(let enteredWordIsEmpty):
+            state.enteredWordIsEmpty = enteredWordIsEmpty
         }
 
         return state