feat: add reload to Hashtags tab for Discovery scene

Mastodon/Scene/Discovery/Hashtags/DiscoveryHashtagsViewController.swift

@@ -31,6 +31,8 @@ final class DiscoveryHashtagsViewController: UIViewController, NeedsDependency,
         return tableView
     }()
     
+    let refreshControl = UIRefreshControl()
+    
     deinit {
         os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", ((#file as NSString).lastPathComponent), #line, #function)
     }
@@ -60,6 +62,9 @@ extension DiscoveryHashtagsViewController {
             tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
         ])
         
+        tableView.refreshControl = refreshControl
+        refreshControl.addTarget(self, action: #selector(DiscoveryHashtagsViewController.refreshControlValueChanged(_:)), for: .valueChanged)
+
         tableView.delegate = self
         viewModel.setupDiffableDataSource(
             tableView: tableView
@@ -80,6 +85,21 @@ extension DiscoveryHashtagsViewController {
     
 }
 
+extension DiscoveryHashtagsViewController {
+    
+    @objc private func refreshControlValueChanged(_ sender: UIRefreshControl) {
+        Task { @MainActor in
+            do {
+                try await viewModel.fetch()
+            } catch {
+                // do nothing
+            }
+            sender.endRefreshing()
+        }   // end Task
+    }
+    
+}
+
 // MARK: - UITableViewDelegate
 extension DiscoveryHashtagsViewController: UITableViewDelegate {
 

Mastodon/Scene/Discovery/Hashtags/DiscoveryHashtagsViewModel.swift

@@ -15,6 +15,8 @@ import MastodonSDK
 
 final class DiscoveryHashtagsViewModel {
     
+    let logger = Logger(subsystem: "DiscoveryHashtagsViewModel", category: "ViewModel")
+    
     var disposeBag = Set<AnyCancellable>()
     
     // input
@@ -61,3 +63,14 @@ final class DiscoveryHashtagsViewModel {
     }
     
 }
+
+extension DiscoveryHashtagsViewModel {
+    
+    @MainActor
+    func fetch() async throws {
+        guard let authenticationBox = context.authenticationService.activeMastodonAuthenticationBox.value else { return }
+        let response = try await context.apiService.trendHashtags(domain: authenticationBox.domain, query: nil)
+        hashtags = response.value.filter { !$0.name.isEmpty }
+        logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): fetch tags: \(response.value.count)")
+    }
+}