Store followed hashtags

The followed hashtags may not load until after the timeline request
completes, and we want to be able to show the hashtag indicator (or at
least make a best effort attempt) immediately.

Pachyderm/Sources/Pachyderm/Client.swift

@@ -261,6 +261,10 @@ public class Client {
         return Request<Account>(method: .post, path: "/api/v1/follows", body: ParametersBody(["uri" => acct]))
     }
     
+    public static func getFollowedHashtags() -> Request<[Hashtag]> {
+        return Request(method: .get, path: "/api/v1/followed_tags")
+    }
+    
     // MARK: - Lists
     public static func getLists() -> Request<[List]> {
         return Request<[List]>(method: .get, path: "/api/v1/lists")

Pachyderm/Sources/Pachyderm/Model/Hashtag.swift

@@ -15,11 +15,14 @@ public class Hashtag: Codable {
     public let url: WebURL
     /// Only present when returned from the trending hashtags endpoint
     public let history: [History]?
+    /// Only present on Mastodon >= 4 and when logged in
+    public let following: Bool?
     
     public init(name: String, url: URL) {
         self.name = name
         self.url = WebURL(url)!
         self.history = nil
+        self.following = nil
     }
     
     public required init(from decoder: Decoder) throws {
@@ -28,6 +31,7 @@ public class Hashtag: Codable {
         // pixelfed (possibly others) don't fully escape special characters in the hashtag url
         self.url = try container.decode(WebURL.self, forKey: .url)
         self.history = try container.decodeIfPresent([History].self, forKey: .history)
+        self.following = try container.decodeIfPresent(Bool.self, forKey: .following)
     }
     
     public func encode(to encoder: Encoder) throws {
@@ -35,12 +39,14 @@ public class Hashtag: Codable {
         try container.encode(name, forKey: .name)
         try container.encode(url, forKey: .url)
         try container.encodeIfPresent(history, forKey: .history)
+        try container.encodeIfPresent(following, forKey: .following)
     }
     
     private enum CodingKeys: String, CodingKey {
         case name
         case url
         case history
+        case following
     }
 }
 

Tusker.xcodeproj/project.pbxproj

@@ -50,6 +50,7 @@
 		D61F758E2933C69C00C0B37F /* StatusUpdatedNotificationTableViewCell.xib in Resources */ = {isa = PBXBuildFile; fileRef = D61F758C2933C69C00C0B37F /* StatusUpdatedNotificationTableViewCell.xib */; };
 		D61F759029353B4300C0B37F /* FileManager+Size.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F758F29353B4300C0B37F /* FileManager+Size.swift */; };
 		D61F759229365C6C00C0B37F /* CollectionViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F759129365C6C00C0B37F /* CollectionViewController.swift */; };
+		D61F75942936F0DA00C0B37F /* FollowedHashtag.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61F75932936F0DA00C0B37F /* FollowedHashtag.swift */; };
 		D620483423D3801D008A63EF /* LinkTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483323D3801D008A63EF /* LinkTextView.swift */; };
 		D620483623D38075008A63EF /* ContentTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483523D38075008A63EF /* ContentTextView.swift */; };
 		D620483823D38190008A63EF /* StatusContentTextView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D620483723D38190008A63EF /* StatusContentTextView.swift */; };
@@ -416,6 +417,7 @@
 		D61F758C2933C69C00C0B37F /* StatusUpdatedNotificationTableViewCell.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = StatusUpdatedNotificationTableViewCell.xib; sourceTree = "<group>"; };
 		D61F758F29353B4300C0B37F /* FileManager+Size.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "FileManager+Size.swift"; sourceTree = "<group>"; };
 		D61F759129365C6C00C0B37F /* CollectionViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CollectionViewController.swift; sourceTree = "<group>"; };
+		D61F75932936F0DA00C0B37F /* FollowedHashtag.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FollowedHashtag.swift; sourceTree = "<group>"; };
 		D620483323D3801D008A63EF /* LinkTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LinkTextView.swift; sourceTree = "<group>"; };
 		D620483523D38075008A63EF /* ContentTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentTextView.swift; sourceTree = "<group>"; };
 		D620483723D38190008A63EF /* StatusContentTextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusContentTextView.swift; sourceTree = "<group>"; };
@@ -881,6 +883,7 @@
 				D6DF95C02533F5DE0027A9B6 /* RelationshipMO.swift */,
 				D6B9366E2828452F00237D0E /* SavedHashtag.swift */,
 				D6B9366C2828444F00237D0E /* SavedInstance.swift */,
+				D61F75932936F0DA00C0B37F /* FollowedHashtag.swift */,
 				D60E2F2D244248BF005F8713 /* MastodonCachePersistentStore.swift */,
 				D6B936702829F72900237D0E /* NSManagedObjectContext+Helpers.swift */,
 			);
@@ -1824,6 +1827,7 @@
 				0450531F22B0097E00100BA2 /* Timline+UI.swift in Sources */,
 				D667E5F52135BCD50057A976 /* ConversationTableViewController.swift in Sources */,
 				D6C7D27D22B6EBF800071952 /* AttachmentsContainerView.swift in Sources */,
+				D61F75942936F0DA00C0B37F /* FollowedHashtag.swift in Sources */,
 				D63CC7122911F57C000E19DE /* StatusBarTappableViewController.swift in Sources */,
 				D620483823D38190008A63EF /* StatusContentTextView.swift in Sources */,
 				D6D3FDE224F46A8D00FF50A5 /* ComposeUIState.swift in Sources */,

Tusker/API/InstanceFeatures.swift

@@ -84,6 +84,14 @@ struct InstanceFeatures {
         }
     }
     
+    var canFollowHashtags: Bool {
+        if case .mastodon(_, .some(let version)) = instanceType {
+            return version >= Version(4, 0, 0)
+        } else {
+            return false
+        }
+    }
+    
     mutating func update(instance: Instance, nodeInfo: NodeInfo?) {
         let ver = instance.version.lowercased()
         if ver.contains("glitch") {

Tusker/API/MastodonController.swift

@@ -49,6 +49,7 @@ class MastodonController: ObservableObject {
     @Published private(set) var instanceFeatures = InstanceFeatures()
     @Published private(set) var lists: [List] = []
     @Published private(set) var customEmojis: [Emoji]?
+    @Published private(set) var followedHashtags: [FollowedHashtag] = []
     
     private var cancellables = Set<AnyCancellable>()
     
@@ -78,6 +79,15 @@ class MastodonController: ObservableObject {
                 self.instanceFeatures.update(instance: instance, nodeInfo: nodeInfo)
             }
             .store(in: &cancellables)
+        
+        $instanceFeatures
+            .filter { [unowned self] in $0.canFollowHashtags && self.followedHashtags.isEmpty }
+            .sink { [unowned self] _ in
+                Task {
+                    await self.loadFollowedHashtags()
+                }
+            }
+            .store(in: &cancellables)
     }
     
     @discardableResult
@@ -321,6 +331,20 @@ class MastodonController: ObservableObject {
         self.lists = new
     }
     
+    @MainActor
+    private func loadFollowedHashtags() async {
+        followedHashtags = (try? persistentContainer.viewContext.fetch(FollowedHashtag.fetchRequest())) ?? []
+        
+        let req = Client.getFollowedHashtags()
+        if let (hashtags, _) = try? await run(req) {
+            self.persistentContainer.updateFollowedHashtags(hashtags) {
+                if case .success(let hashtags) = $0 {
+                    self.followedHashtags = hashtags
+                }
+            }
+        }
+    }
+    
 }
 
 private struct ListComparator: SortComparator {

Tusker/CoreData/FollowedHashtag.swift

@@ -0,0 +1,38 @@
+//
+//  FollowedHashtag.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 11/29/22.
+//  Copyright © 2022 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+import CoreData
+import Pachyderm
+import WebURLFoundationExtras
+
+@objc(FollowedHashtag)
+public final class FollowedHashtag: NSManagedObject {
+    
+    @nonobjc public class func fetchRequest() -> NSFetchRequest<FollowedHashtag> {
+        return NSFetchRequest<FollowedHashtag>(entityName: "FollowedHashtag")
+    }
+    
+    @nonobjc public class func fetchRequest(name: String) -> NSFetchRequest<FollowedHashtag> {
+        let req = NSFetchRequest<FollowedHashtag>(entityName: "FollowedHashtag")
+        req.predicate = NSPredicate(format: "name = %@", name)
+        return req
+    }
+    
+    @NSManaged public var name: String
+    @NSManaged public var url: URL
+    
+}
+
+extension FollowedHashtag {
+    convenience init(hashtag: Hashtag, context: NSManagedObjectContext) {
+        self.init(context: context)
+        self.name = hashtag.name
+        self.url = URL(hashtag.url)!
+    }
+}

Tusker/CoreData/MastodonCachePersistentStore.swift

@@ -267,6 +267,38 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         }
     }
     
+    func updateFollowedHashtags(_ hashtags: [Hashtag], completion: @escaping (Result<[FollowedHashtag], Error>) -> Void) {
+        viewContext.perform {
+            do {
+                var all = try self.viewContext.fetch(FollowedHashtag.fetchRequest())
+                
+                let toDelete = all.filter { existing in !hashtags.contains(where: { $0.name == existing.name }) }.map(\.objectID)
+                if !toDelete.isEmpty {
+                    try self.viewContext.execute(NSBatchDeleteRequest(objectIDs: toDelete))
+                }
+                
+                for hashtag in hashtags where !all.contains(where: { $0.name == hashtag.name}) {
+                    let mo = FollowedHashtag(hashtag: hashtag, context: self.viewContext)
+                    all.append(mo)
+                }
+                
+                self.save(context: self.viewContext)
+                completion(.success(all))
+            } catch {
+                completion(.failure(error))
+            }
+        }
+    }
+    
+    func hasFollowedHashtag(_ hashtag: Hashtag) -> Bool {
+        do {
+            let req = FollowedHashtag.fetchRequest(name: name)
+            return try viewContext.count(for: req) > 0
+        } catch {
+            return false
+        }
+    }
+    
     @objc private func managedObjectsDidChange(_ notification: Foundation.Notification) {
         let changes = hasChangedSavedHashtagsOrInstances(notification)
         if changes.hashtags {

Tusker/CoreData/Tusker.xcdatamodeld/Tusker.xcdatamodel/contents

@@ -28,6 +28,10 @@
             </uniquenessConstraint>
         </uniquenessConstraints>
     </entity>
+    <entity name="FollowedHashtag" representedClassName="FollowedHashtag" syncable="YES">
+        <attribute name="name" attributeType="String"/>
+        <attribute name="url" attributeType="URI"/>
+    </entity>
     <entity name="Relationship" representedClassName="RelationshipMO" syncable="YES">
         <attribute name="accountID" optional="YES" attributeType="String"/>
         <attribute name="blocking" optional="YES" attributeType="Boolean" usesScalarValueType="YES"/>