Fix loading of home timeline (IOS-176)

Mastodon/Scene/HomeTimeline/HomeTimelineViewController+DataSourceProvider.swift

@@ -21,7 +21,6 @@ extension HomeTimelineViewController: DataSourceProvider {
         
         switch item {
         case .feed(let feed):
-            let managedObjectContext = context.managedObjectContext
             let item: DataSourceItem? = {
                 guard feed.kind == .home else { return nil }
                 if let status = feed.status {

Mastodon/Scene/HomeTimeline/HomeTimelineViewModel.swift

@@ -80,7 +80,7 @@ final class HomeTimelineViewModel: NSObject {
     init(context: AppContext, authContext: AuthContext) {
         self.context  = context
         self.authContext = authContext
-        self.fetchedResultsController = FeedFetchedResultsController()
+        self.fetchedResultsController = FeedFetchedResultsController(context: context, authContext: authContext)
         self.homeTimelineNavigationBarTitleViewModel = HomeTimelineNavigationBarTitleViewModel(context: context)
         super.init()
         homeTimelineNeedRefresh
@@ -97,6 +97,8 @@ final class HomeTimelineViewModel: NSObject {
                 self.homeTimelineNeedRefresh.send()
             }
             .store(in: &disposeBag)
+        
+        self.fetchedResultsController.loadInitial(kind: .home)
     }
 }
 
@@ -110,7 +112,7 @@ extension HomeTimelineViewModel {
 
 extension HomeTimelineViewModel {
     func timelineDidReachEnd() {
-        #warning("Check if required, e.g. when locally caching MastodonStatus")
+        fetchedResultsController.loadNext(kind: .home)
     }
 }
 
@@ -122,29 +124,9 @@ extension HomeTimelineViewModel {
         guard let diffableDataSource = diffableDataSource else { return }
         var snapshot = diffableDataSource.snapshot()
 
-        
-//        let managedObjectContext = context.managedObjectContext
-//        let key = "LoadMore@\(record.objectID)"
-//        
-//        guard let feed = record.object(in: managedObjectContext) else { return }
-        
         guard let status = record.status else { return }
         record.isLoadingMore = true
-        
-//        // keep transient property live
-//        managedObjectContext.cache(feed, key: key)
-//        defer {
-//            managedObjectContext.cache(nil, key: key)
-//        }
-//        do {
-//            // update state
-//            try await managedObjectContext.performChanges {
-//                feed.update(isLoadingMore: true)
-//            }
-//        } catch {
-//            assertionFailure(error.localizedDescription)
-//        }
-        
+
         // reconfigure item
         snapshot.reconfigureItems([item])
         await updateSnapshotUsingReloadData(snapshot: snapshot)

Mastodon/Scene/Notification/NotificationTimeline/NotificationTimelineViewModel.swift

@@ -52,7 +52,7 @@ final class NotificationTimelineViewModel {
         self.context = context
         self.authContext = authContext
         self.scope = scope
-        self.feedFetchedResultsController = FeedFetchedResultsController()
+        self.feedFetchedResultsController = FeedFetchedResultsController(context: context, authContext: authContext)
     }
     
     

MastodonSDK/Sources/MastodonCore/FetchedResultsController/FeedFetchedResultsController.swift

@@ -14,6 +14,44 @@ import MastodonSDK
 final public class FeedFetchedResultsController {
 
     @Published public var records: [MastodonFeed] = []
+    
+    private let context: AppContext
+    private let authContext: AuthContext
 
-    public init() {}
+    public init(context: AppContext, authContext: AuthContext) {
+        self.context = context
+        self.authContext = authContext
+    }
+    
+    public func loadInitial(kind: MastodonFeed.Kind) {
+        Task {
+            records = try await load(kind: kind, sinceId: nil)
+        }
+    }
+    
+    public func loadNext(kind: MastodonFeed.Kind) {
+        Task {
+            guard let lastId = records.last?.status?.id else {
+                return loadInitial(kind: kind)
+            }
+            
+            records = try await load(kind: kind, sinceId: lastId)
+        }
+    }
+}
+
+private extension FeedFetchedResultsController {
+    func load(kind: MastodonFeed.Kind, sinceId: MastodonStatus.ID?) async throws -> [MastodonFeed] {
+        switch kind {
+        case .home:
+            return try await context.apiService.homeTimeline(sinceID: sinceId, authenticationBox: authContext.mastodonAuthenticationBox)
+                .value.map { .fromStatus(.fromEntity($0), kind: .home) }
+        case .notificationAll:
+            return try await context.apiService.notifications(maxID: nil, scope: .everything, authenticationBox: authContext.mastodonAuthenticationBox)
+                .value.map { .fromNotification($0, kind: .notificationAll) }
+        case .notificationMentions:
+            return try await context.apiService.notifications(maxID: nil, scope: .mentions, authenticationBox: authContext.mastodonAuthenticationBox)
+                .value.map { .fromNotification($0, kind: .notificationMentions) }
+        }
+    }
 }

MastodonSDK/Sources/MastodonCore/FetchedResultsController/StatusFetchedResultsController.swift

@@ -13,7 +13,8 @@ import MastodonSDK
 
 public final class StatusFetchedResultsController {
     @MainActor
-    @Published public private(set) var records: [MastodonStatus] = []
+    @Published 
+    public private(set) var records: [MastodonStatus] = []
     
     @MainActor
     public init(records: [MastodonStatus] = []) {

MastodonSDK/Sources/MastodonSDK/MastodonFeed.swift

@@ -4,6 +4,14 @@ import Foundation
 import CoreDataStack
 
 public final class MastodonFeed {
+    
+    public enum Kind {
+        case home
+        case notificationAll
+        case notificationMentions
+    }
+    
+    public let id: String
     public var hasMore: Bool = false
     public var isLoadingMore: Bool = false
     
@@ -13,6 +21,7 @@ public final class MastodonFeed {
     public let kind: Feed.Kind
     
     init(hasMore: Bool, isLoadingMore: Bool, status: MastodonStatus?, notification: Mastodon.Entity.Notification?, kind: Feed.Kind) {
+        self.id = status?.id ?? notification?.id ?? UUID().uuidString
         self.hasMore = hasMore
         self.isLoadingMore = isLoadingMore
         self.status = status
@@ -45,10 +54,11 @@ public extension MastodonFeed {
 
 extension MastodonFeed: Hashable {
     public static func == (lhs: MastodonFeed, rhs: MastodonFeed) -> Bool {
-        lhs.status?.id == rhs.status?.id || lhs.notification?.id == rhs.notification?.id
+        lhs.id == rhs.id && (lhs.status?.id == rhs.status?.id || lhs.notification?.id == rhs.notification?.id)
     }
     
     public func hash(into hasher: inout Hasher) {
+        hasher.combine(id)
         hasher.combine(status)
         hasher.combine(notification)
     }