feat: 도서 검색 실패 기능 개발

src/Projects/BKData/Sources/DataAssembly.swift

@@ -165,5 +165,9 @@ public struct DataAssembly: Assembly {
                 pushTokenStore: pushTokenStore
             )
         }
+
+        container.register(type: ExternalLinkRepository.self) { _ in
+            return DefaultExternalLinkRepository()
+        }
     }
 }

src/Projects/BKData/Sources/Repository/DefaultExternalLinkRepository.swift

@@ -0,0 +1,37 @@
+// Copyright © 2026 Booket. All rights reserved
+
+import BKCore
+import BKDomain
+import Combine
+import UIKit
+
+final class DefaultExternalLinkRepository: ExternalLinkRepository {
+    func canOpen(_ urlString: String) -> Bool {
+        guard let url = URL(string: urlString) else {
+            Log.error("유효하지 않은 URL 형식: \(urlString)", logger: AppLogger.network)
+            return false
+        }
+        return UIApplication.shared.canOpenURL(url)
+    }
+
+    func open(_ urlString: String) -> AnyPublisher<Bool, Never> {
+        return Future<Bool, Never> { promise in
+            guard let url = URL(string: urlString) else {
+                Log.error("URL 객체 생성 실패: \(urlString)", logger: AppLogger.network)
+                promise(.success(false))
+                return
+            }
+
+            DispatchQueue.main.async {
+                if UIApplication.shared.canOpenURL(url) {
+                    UIApplication.shared.open(url, options: [:]) { success in
+                        promise(.success(success))
+                    }
+                } else {
+                    promise(.success(false))
+                }
+            }
+        }
+        .eraseToAnyPublisher()
+    }
+}

src/Projects/BKDomain/Sources/DomainAssembly.swift

@@ -255,5 +255,10 @@ public struct DomainAssembly: Assembly {
                 notificationRepository: notificationRepository
             )
         }
+
+        container.register(type: OpenExternalLinkUseCase.self) { _ in
+            @Autowired var repository: ExternalLinkRepository
+            return DefaultOpenExternalLinkUseCase(repository: repository)
+        }
     }
 }

src/Projects/BKDomain/Sources/Interface/Repository/ExternalLinkRepository.swift

@@ -0,0 +1,20 @@
+// Copyright © 2026 Booket. All rights reserved
+
+import Combine
+import Foundation
+
+/// 외부 시스템(앱 스킴 또는 웹 브라우저)으로 링크를 연결하고 상태를 확인하는 인터페이스입니다.
+public protocol ExternalLinkRepository {
+
+    /// 전달받은 URL 문자열이 현재 시스템에서 실행 가능한지 여부를 확인합니다.
+    ///
+    /// - Parameter urlString: 확인할 대상 URL 문자열 (예: "kakaoplus://...", "https://...")
+    /// - Returns: 실행 가능 여부 (true: 실행 가능, false: 실행 불가 또는 스킴 미등록)
+    func canOpen(_ urlString: String) -> Bool
+
+    /// 전달받은 URL 문자열을 통해 외부 링크를 실행합니다.
+    ///
+    /// - Parameter urlString: 실행할 대상 URL 문자열
+    /// - Returns: 실행 성공 여부를 전달하는 Publisher (true: 실행 성공, false: 실행 실패)
+    func open(_ urlString: String) -> AnyPublisher<Bool, Never>
+}

src/Projects/BKDomain/Sources/Interface/Usecase/OpenExternalLinkUseCase.swift

@@ -0,0 +1,10 @@
+// Copyright © 2026 Booket. All rights reserved
+
+import Combine
+import Foundation
+
+public protocol OpenExternalLinkUseCase {
+    /// 외부 링크를 실행합니다.
+    /// appScheme이 있고 실행 가능한 경우 우선 실행하며, 실패 시 urlString을 실행합니다.
+    func execute(urlString: String, appScheme: String?) -> AnyPublisher<Bool, Never>
+}

src/Projects/BKDomain/Sources/UseCase/DefaultOpenExternalLinkUseCase.swift

@@ -0,0 +1,20 @@
+// Copyright © 2026 Booket. All rights reserved
+
+import Combine
+import Foundation
+
+public struct DefaultOpenExternalLinkUseCase: OpenExternalLinkUseCase {
+    private let repository: ExternalLinkRepository
+
+    init(repository: ExternalLinkRepository) {
+        self.repository = repository
+    }
+
+    public func execute(urlString: String, appScheme: String?) -> AnyPublisher<Bool, Never> {
+        if let appScheme = appScheme, repository.canOpen(appScheme) {
+            return repository.open(appScheme)
+        }
+
+        return repository.open(urlString)
+    }
+}

src/Projects/BKPresentation/Sources/ArchiveFlow/View/ArchiveView.swift

@@ -73,7 +73,7 @@ final class ArchiveView: BaseView, UIGestureRecognizerDelegate {
         setupLayout()
         updateEmptyState()
 
-        emptyStateView.onTapLogin = { [weak self] in
+        emptyStateView.onTapActionButton = { [weak self] in
             self?.eventPublisher.send(.loginButtonTapped)
         }
 

src/Projects/BKPresentation/Sources/ArchiveFlow/View/EmptyStateView.swift

@@ -6,7 +6,11 @@ import UIKit
 import SnapKit
 
 final class EmptyStateView: BaseView {
-    var onTapLogin: (() -> Void)?
+    var onTapActionButton: (() -> Void)?
+
+    private var memberCustomTitle: String?
+    private var memberCustomDescription: String?
+    private var memberCustomActionTitle: String?
 
     private var cancellables = Set<AnyCancellable>()
     private let titleLabel = BKLabel(
@@ -23,13 +27,13 @@ final class EmptyStateView: BaseView {
         alignment: .center
     )
 
-    private let loginButton: BKButton = {
+    private let actionButton: BKButton = {
         let button = BKButton(style: .secondary, size: .small)
         return button
     }()
 
     private lazy var stackView: UIStackView = {
-        let stackView = UIStackView(arrangedSubviews: [titleLabel, descriptionLabel, loginButton])
+        let stackView = UIStackView(arrangedSubviews: [titleLabel, descriptionLabel, actionButton])
         stackView.axis = .vertical
         stackView.alignment = .center
         stackView.spacing = 8
@@ -50,18 +54,28 @@ final class EmptyStateView: BaseView {
     }
 
     override func configure() {
-        loginButton.title = Constants.loginButtonTitle
-        loginButton.addTarget(self, action: #selector(tapLogin), for: .touchUpInside)
+        actionButton.addTarget(self, action: #selector(tapActionButton), for: .touchUpInside)
 
         AccessModeCenter.shared.mode
             .receive(on: DispatchQueue.main)
             .sink { [weak self] mode in
-                self?.apply(mode: mode)
+                self?.updateUI(for: mode)
             }
             .store(in: &cancellables)
 
-        apply(mode: AccessModeCenter.shared.mode.value)
+        updateUI(for: AccessModeCenter.shared.mode.value)
     }
+
+    public func setContent(title: String, description: String, actionTitle: String? = nil) {
+        self.memberCustomTitle = title
+        self.memberCustomDescription = description
+        self.memberCustomActionTitle = actionTitle
+
+        if AccessModeCenter.shared.mode.value == .member {
+            updateUI(for: .member)
+        }
+    }
+
 }
 
 private extension EmptyStateView {
@@ -73,20 +87,31 @@ private extension EmptyStateView {
         static let loginButtonTitle = "로그인하기"
     }
 
-    func apply(mode: AppAccessMode) {
+    private func updateUI(for mode: AppAccessMode) {
         switch mode {
         case .guest:
             titleLabel.setText(text: Constants.guestTitle)
             descriptionLabel.setText(text: Constants.guestSubtitle)
-            loginButton.isHidden = false
+            actionButton.title = Constants.loginButtonTitle
+            actionButton.isHidden = false
+
         case .member:
-            titleLabel.setText(text: Constants.memberTitle)
-            descriptionLabel.setText(text: Constants.memberSubtitle)
-            loginButton.isHidden = true
+            let title = memberCustomTitle ?? Constants.memberTitle
+            let desc = memberCustomDescription ?? Constants.memberSubtitle
+
+            titleLabel.setText(text: title)
+            descriptionLabel.setText(text: desc)
+
+            if let actionTitle = memberCustomActionTitle {
+                actionButton.title = actionTitle
+                actionButton.isHidden = false
+            } else {
+                actionButton.isHidden = true
+            }
         }
     }
 
-    @objc func tapLogin() {
-        onTapLogin?()
+    @objc func tapActionButton() {
+        onTapActionButton?()
     }
 }

src/Projects/BKPresentation/Sources/Constant/URLConstants.swift

@@ -0,0 +1,19 @@
+// Copyright © 2026 Booket. All rights reserved
+
+import Foundation
+
+private final class PresentationBundleToken {}
+
+public enum URLConstants {
+    private static let bundle = Bundle(for: PresentationBundleToken.self)
+
+    private static let kakaoAccount: String = {
+        guard let value = bundle.object(forInfoDictionaryKey: "KAKAO_ACCOUNT") as? String else {
+            fatalError("Can't load KAKAO_ACCOUNT")
+        }
+        return value
+    }()
+
+    public static let kakaoAppScheme = "kakaoplus://plusfriend/home/\(kakaoAccount)"
+    public static let kakaoChatURL = "https://pf.kakao.com/\(kakaoAccount)/chat"
+}

src/Projects/BKPresentation/Sources/MainFlow/Search/Coordinator/SearchCoordinator.swift

@@ -1,5 +1,9 @@
 // Copyright © 2025 Booket. All rights reserved
 
+import BKCore
+import BKDesign
+import BKDomain
+import Combine
 import UIKit
 
 final class SearchCoordinator: Coordinator {
@@ -8,6 +12,9 @@ final class SearchCoordinator: Coordinator {
     var navigationController: UINavigationController
 
     private let searchViewType: SearchViewType
+    private var cancellables = Set<AnyCancellable>()
+
+    @Autowired var openExternalLinkUseCase: OpenExternalLinkUseCase
 
     init(
         parentCoordinator: Coordinator?,
@@ -57,4 +64,22 @@ extension SearchCoordinator {
         addChildCoordinator(bookDetailCoordinator)
         bookDetailCoordinator.start()
     }
+
+    func showRequestPage() {
+        let webURL = URLConstants.kakaoChatURL
+        let appScheme = URLConstants.kakaoAppScheme
+
+        Log.debug("외부 링크 오픈 시도 - Web: \(webURL), App: \(appScheme)", logger: AppLogger.ui)
+
+        openExternalLinkUseCase.execute(urlString: webURL, appScheme: appScheme)
+            .receive(on: DispatchQueue.main)
+            .sink { success in
+                if success {
+                    Log.debug("외부 링크 오픈 성공", logger: AppLogger.ui)
+                } else {
+                    Log.error("외부 링크 오픈 실패 (URL 스킴 확인 필요)", logger: AppLogger.ui)
+                }
+            }
+            .store(in: &cancellables)
+    }
 }

src/Projects/BKPresentation/Sources/MainFlow/Search/View/SearchView.swift

@@ -26,6 +26,7 @@ final class SearchView: BaseView {
 
     private let divider = BKDivider(type: .medium)
     private let header = SearchSectionHeaderView()
+    private let emptyView = EmptyStateView()
 
     private lazy var collectionView: UICollectionView = {
         return setupCollectionView()
@@ -38,13 +39,23 @@ final class SearchView: BaseView {
     private var layoutMode = CollectionLayoutMode.beforeSearch
 
     override func setupView() {
-        addSubviews(searchBar, divider, header, collectionView)
+        addSubviews(searchBar, divider, header, collectionView, emptyView)
     }
 
     override func configure() {
         searchBar.setOnReturn { [weak self] text in
             self?.eventPublisher.send(.search(text))
         }
+
+        emptyView.onTapActionButton = { [weak self] in
+            let currentMode = AccessModeCenter.shared.mode.value
+
+            if currentMode == .guest {
+                self?.eventPublisher.send(.goToLogin)
+            } else {
+                self?.eventPublisher.send(.goToRequestPage)
+            }
+        }
     }
 
     override func setupLayout() {
@@ -72,6 +83,12 @@ final class SearchView: BaseView {
                 .offset(LayoutConstants.headerOffset)
             $0.leading.trailing.bottom.equalToSuperview()
         }
+
+        emptyView.snp.makeConstraints {
+            $0.top.equalTo(header.snp.bottom)
+                .offset(LayoutConstants.headerOffset)
+            $0.leading.trailing.bottom.equalToSuperview()
+        }
     }
 
     func setSearchBarPlaceholder(with placeholder: String) {
@@ -90,6 +107,9 @@ final class SearchView: BaseView {
 
         switch state {
         case .recent(let state):
+            emptyView.isHidden = true
+            collectionView.isHidden = false
+
             if state.queries.isEmpty {
                 collectionView.backgroundView = makeEmptyLabel(state.placeholder)
             } else {
@@ -102,12 +122,15 @@ final class SearchView: BaseView {
         case .result(let state):
             let isEmpty = state.books.isEmpty && state.bookInfos.isEmpty
             if isEmpty {
-                header.layoutIfNeeded()
-                let headerHeight = header.bounds.height
-                let offset = -(headerHeight / 2.0)
-                collectionView.backgroundView = makeEmptyLabel(state.placeholder, verticalOffset: offset)
+                updateEmptyState(
+                    isHidden: false,
+                    title: "아직 등록된 책이 없어요",
+                    description: "카카오톡 채널로 문의를 남겨주세요",
+                    buttonTitle: "문의하기"
+                )
                 searchBar.setClearButtonMode(.whileEditing)
             } else {
+                updateEmptyState(isHidden: true)
                 collectionView.backgroundView = nil
                 snapshot.appendSections([.result])
                 // Book과 BookInfo 모두 처리
@@ -273,11 +296,27 @@ private extension SearchView {
             $0.centerX.equalToSuperview()
             $0.centerY.equalToSuperview().offset(verticalOffset)
         }
-
+        
         return container
     }
 
-    @objc func searchButtonTapped() {
+    private func updateEmptyState(
+        isHidden: Bool,
+        title: String = "",
+        description: String = "",
+        buttonTitle: String = ""
+    ) {
+        emptyView.isHidden = isHidden
+        collectionView.isHidden = !isHidden
+
+        if !isHidden {
+            emptyView.setContent(title: title, description: description, actionTitle: buttonTitle)
+            bringSubviewToFront(emptyView)
+        }
+    }
+
+    @objc
+    func searchButtonTapped() {
         guard let text = searchBar.text, !text.isEmpty else { return }
         eventPublisher.send(.search(text))
     }