gistfile1.txt

class ShareViewController: UIViewController {
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        // Get the all encompasing object that holds whatever was shared. If not, dismiss view.
        guard let extensionItem = extensionContext?.inputItems.first as? NSExtensionItem else {
            self.extensionContext?.completeRequest(returningItems: nil, completionHandler: nil)
            return
        }

        accessWebpageProperties(extensionItem: extensionItem)
    }
    
    private func accessWebpageProperties(extensionItem: NSExtensionItem) {
        guard let attachments = extensionItem.attachments else {
            return
        }
        
        Task {
            for attachment in attachments {
                
                if let url = await handleIncomingURL(itemProvider: attachment) {
                    shareAndBye(url: url)
                    return
                }
                
                if let url = await handleIncomingText(itemProvider: attachment) {
                    shareAndBye(url: url)
                    return
                }
            }
            
            bye()
        }
    }
    
    private func handleIncomingURL(itemProvider: NSItemProvider) async -> String? {
        do {
            if let url = try await itemProvider.loadItem(forTypeIdentifier: UTType.url.identifier, options: nil) as? NSURL {
                
                if let urlString = url.absoluteString?.trimmingCharacters(in: .whitespacesAndNewlines), ShareViewController.isValidWebsiteURL(urlString) {
                    return urlString
                }
            }
        } catch {
            // Handle errors appropriately here
            print("Error handling incoming URL: \(error)")
        }
        
        return nil
    }
    
    private func handleIncomingText(itemProvider: NSItemProvider) async -> String? {
        do {
            let text = try await itemProvider.loadItem(forTypeIdentifier: UTType.text.identifier, options: nil) as? String
            
            if let text = text?.trimmingCharacters(in: .whitespacesAndNewlines) {
                do {
                    let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
                    let matches = detector.matches(
                        in: text,
                        options: [],
                        range: NSRange(location: 0, length: text.utf16.count)
                    )

                    for match in matches {
                        if let range = Range(match.range, in: text) {
                            
                            let url = String(text[range]).trimmingCharacters(in: .whitespacesAndNewlines)
                            
                            if ShareViewController.isValidWebsiteURL(url) {
                                return url
                            }
                        }
                    }
                } catch let error {
                    print("Do-Try Error: \(error.localizedDescription)")
                }
            }
        } catch {
            // Handle errors appropriately here
            print("Error handling incoming text: \(error)")
        }
        
        return nil
    }

    // TODO: Need to fix this.
    private static func isValidWebsiteURL(_ urlString: String) -> Bool {
        if urlString.isEmpty {
            return false
        }
        
        if let url = URL(string: urlString), url.host != nil, (url.scheme == "http" || url.scheme == "https") {
            return true
        }
        
        return false
    }
    

    
    @MainActor
    private func shareAndBye(url: String) {
        self.extensionContext?.completeRequest(returningItems: nil, completionHandler: { _ in
            if let encodedURL = url.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) {
                let appURL = "melonote://share?url=" + encodedURL
                guard let url = URL(string: appURL) else { return }
                _ = self.openURL(url)
            }
        })
    }
    
    @MainActor
    private func bye() {
        self.extensionContext?.completeRequest(returningItems: nil, completionHandler: nil)
    }
    
    // Courtesy: https://stackoverflow.com/a/44499222/13363449 👇🏾
    // Function must be named exactly like this so a selector can be found by the compiler!
    // Anyway - it's another selector in another instance that would be "performed" instead.
    @objc private func openURL(_ url: URL) -> Bool {
        var responder: UIResponder? = self
        while responder != nil {
            if let application = responder as? UIApplication {
                return application.perform(#selector(openURL(_:)), with: url) != nil
            }
            responder = responder?.next
        }
        return false
    }
}