feat: add prefetching feaature for reporting

Mastodon/Scene/Report/ReportViewController.swift

@@ -68,6 +68,7 @@ class ReportViewController: UIViewController, NeedsDependency {
         tableView.backgroundColor = .clear
         tableView.translatesAutoresizingMaskIntoConstraints = false
         tableView.delegate = self
+        tableView.prefetchDataSource = self
         tableView.allowsMultipleSelection = true
         return tableView
     }()
@@ -310,6 +311,7 @@ class ReportViewController: UIViewController, NeedsDependency {
     }
 }
 
+// MARK: - UITableViewDelegate
 extension ReportViewController: UITableViewDelegate {
     func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         guard let item = viewModel.diffableDataSource?.itemIdentifier(for: indexPath) else {
@@ -326,6 +328,14 @@ extension ReportViewController: UITableViewDelegate {
     }
 }
 
+// MARK: - UITableViewDataSourcePrefetching
+extension ReportViewController: UITableViewDataSourcePrefetching {
+    func tableView(_ tableView: UITableView, prefetchRowsAt indexPaths: [IndexPath]) {
+        viewModel.prefetchData(prefetchRowsAt: indexPaths)
+    }
+}
+
+// MARK: - UITextViewDelegate
 extension ReportViewController: UITextViewDelegate {
     func textViewDidChange(_ textView: UITextView) {
         self.comment.send(textView.text)

Mastodon/Scene/Report/ReportViewModel+Data.swift

@@ -97,4 +97,42 @@ extension ReportViewModel {
             }
             .store(in: &disposeBag)
     }
+    
+    func prefetchData(prefetchRowsAt indexPaths: [IndexPath]) {
+        guard let diffableDataSource = diffableDataSource else { return }
+        
+        // prefetch reply status
+        guard let activeMastodonAuthenticationBox = context.authenticationService.activeMastodonAuthenticationBox.value else { return }
+        let domain = activeMastodonAuthenticationBox.domain
+        
+        var statusObjectIDs: [NSManagedObjectID] = []
+        for indexPath in indexPaths {
+            let item = diffableDataSource.itemIdentifier(for: indexPath)
+            switch item {
+            case .reportStatus(let objectID, _):
+                statusObjectIDs.append(objectID)
+            default:
+                continue
+            }
+        }
+        
+        let backgroundManagedObjectContext = context.backgroundManagedObjectContext
+        backgroundManagedObjectContext.perform { [weak self] in
+            guard let self = self else { return }
+            for objectID in statusObjectIDs {
+                let status = backgroundManagedObjectContext.object(with: objectID) as! Status
+                guard let replyToID = status.inReplyToID, status.replyTo == nil else {
+                    // skip
+                    continue
+                }
+                self.context.statusPrefetchingService.prefetchReplyTo(
+                    domain: domain,
+                    statusObjectID: status.objectID,
+                    statusID: status.id,
+                    replyToStatusID: replyToID,
+                    authorizationBox: activeMastodonAuthenticationBox
+                )
+            }
+        }
+    }
 }