[Library] Coordination library (#15)

This PR contains the work done to implement the necessary protocols and router to implement the Coordinators pattern in the app.

Reviewed-on: rock-n-code/app-reviews#15
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Libraries/Coordination/Kit/Sources/Protocols/Coordinator.swift

@@ -0,0 +1,57 @@
+//
+//  Coordinator.swift
+//  ReviewsCoordinationKit
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+public protocol Coordinator: AnyObject {
+    
+    // MARK: Properties
+    var children: [Coordinator] { get set }
+    var router: Router { get }
+    
+    // MARK: Functions
+    func present(animated: Bool, onDismiss: Router.OnDismissClosure?)
+    
+}
+
+// MARK: - Implementations
+public extension Coordinator {
+
+    // MARK: Functions
+    func present(
+        child: Coordinator,
+        animated: Bool,
+        onDismiss: Router.OnDismissClosure? = nil
+    ) {
+        store(child)
+
+        child.present(animated: animated) { [weak self, weak child] in
+            guard let self, let child else { return }
+            
+            self.free(child)
+            onDismiss?()
+        }
+    }
+
+    func dismiss(animated: Bool) {
+        router.dismiss(animated: animated)
+    }
+    
+}
+
+// MARK: - Helpers
+private extension Coordinator {
+    
+    // MARK: Functions
+    func store(_ coordinator: Coordinator) {
+        children.append(coordinator)
+    }
+    
+    func free(_ coordinator: Coordinator) {
+        children = children.filter { $0 !== coordinator }
+    }
+    
+}

Libraries/Coordination/Kit/Sources/Protocols/Router.swift

@@ -0,0 +1,42 @@
+//
+//  Router.swift
+//  ReviewsCoordinationKet
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+public protocol Router: AnyObject {
+    
+    // MARK: Type aliases
+    typealias OnDismissClosure = () -> Void
+    
+    // MARK: Functions
+    func present(
+        _ viewController: UIViewController,
+        animated: Bool,
+        onDismiss: OnDismissClosure?
+    )
+
+    func dismiss(animated: Bool)
+    
+}
+
+// MARK: - Implementations
+public extension Router {
+    
+    // MARK: Functions
+    func present(
+        _ viewController: UIViewController,
+        animated: Bool
+    ) {
+        present(
+            viewController,
+            animated: animated,
+            onDismiss: nil
+        )
+    }
+    
+}

Libraries/Coordination/Kit/Sources/Routers/NavigationRouter.swift

@@ -0,0 +1,55 @@
+//
+//  NavigationRouter.swift
+//  ReviewsCoordinationKit
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+public class NavigationRouter: NSObject {
+    
+    // MARK: Properties
+    var navigationController: UINavigationController
+    var onDismissForViewController: [UIViewController: Router.OnDismissClosure] = [:]
+    
+    // MARK: Initialisers
+    init(navigationController: UINavigationController) {
+        self.navigationController = navigationController
+        
+        super.init()
+        
+        self.navigationController.delegate = self
+    }
+    
+    // MARK: Functions
+    func performOnDismiss(for viewController: UIViewController) {
+        guard let onDismiss = onDismissForViewController[viewController] else {
+            return
+        }
+        
+        onDismiss()
+        
+        onDismissForViewController[viewController] = nil
+    }
+    
+}
+
+// MARK: - UINavigationControllerDelegate
+extension NavigationRouter: UINavigationControllerDelegate {
+    
+    // MARK: Functions
+    public func navigationController(
+        _ navigationController: UINavigationController,
+        didShow viewController: UIViewController,
+        animated: Bool
+    ) {
+        guard let viewControllerToDismiss = navigationController.transitionCoordinator?.viewController(forKey: .from) else {
+            return
+        }
+        
+        performOnDismiss(for: viewControllerToDismiss)
+    }
+    
+}

Libraries/Coordination/Kit/Sources/Routers/PushRouter.swift

@@ -0,0 +1,56 @@
+//
+//  File.swift
+//  ReviewsCoordinationKit
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+public class PushRouter: NavigationRouter {
+    
+    // MARK: Constants
+    private let rootViewController: UIViewController?
+    
+    // MARK: Initialisers
+    public init(
+        navigationController: UINavigationController,
+        rootViewController: UIViewController? = nil
+    ) {
+        self.rootViewController = navigationController.viewControllers.first ?? rootViewController
+        
+        super.init(navigationController: navigationController)
+    }
+    
+}
+
+// MARK: - Router
+extension PushRouter: Router {
+    
+    // MARK: Functions
+    public func present(
+        _ viewController: UIViewController,
+        animated: Bool,
+        onDismiss: OnDismissClosure?
+    ) {
+        onDismissForViewController[viewController] = onDismiss
+        
+        navigationController.pushViewController(viewController, animated: animated)
+    }
+    
+    public func dismiss(animated: Bool) {
+        guard let rootViewController else {
+            navigationController.popViewController(animated: animated)
+            return
+        }
+        
+        performOnDismiss(for: rootViewController)
+        
+        navigationController.popToViewController(
+            rootViewController,
+            animated: animated
+        )
+    }
+    
+}

Libraries/Coordination/Kit/Sources/Routers/WindowRouter.swift

@@ -0,0 +1,35 @@
+//
+//  WindowRouter.swift
+//  ReviewsCoordinationKit
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+public class WindowRouter: Router {
+    
+    // MARK: Constants
+    private let window: UIWindow?
+    
+    // MARK: Initialisers
+    public init(window: UIWindow?) {
+        self.window = window
+    }
+    
+    // MARK: Functions
+    public func present(
+        _ viewController: UIViewController,
+        animated: Bool,
+        onDismiss: OnDismissClosure?
+    ) {
+        window?.rootViewController = viewController
+        window?.makeKeyAndVisible()
+    }
+    
+    public func dismiss(animated: Bool) {
+        // Nothing to do here...
+    }
+    
+}