Subscribe and unsubscribe to talk page topics

Wikipedia/Code/TalkPageCellViewModel.swift

@@ -7,6 +7,7 @@ final class TalkPageCellViewModel {
 
     let topicTitle: String
     let timestamp: Date?
+    let topicName: String
 
     let id: String
     var leadComment: TalkPageCellCommentViewModel
@@ -21,10 +22,11 @@ final class TalkPageCellViewModel {
 
     let isUserLoggedIn: Bool
 
-    init(id: String, topicTitle: String, timestamp: Date?, leadComment: TalkPageCellCommentViewModel, replies: [TalkPageCellCommentViewModel], activeUsersCount: String, isUserLoggedIn: Bool) {
+    init(id: String, topicTitle: String, timestamp: Date?, topicName: String, leadComment: TalkPageCellCommentViewModel, replies: [TalkPageCellCommentViewModel], activeUsersCount: String, isUserLoggedIn: Bool) {
         self.id = id
         self.topicTitle = topicTitle
         self.timestamp = timestamp
+        self.topicName = topicName
         self.leadComment = leadComment
         self.replies = replies
         self.activeUsersCount = activeUsersCount

Wikipedia/Code/TalkPageDataController.swift

@@ -20,7 +20,7 @@ class TalkPageDataController {
 
     // MARK: Public
 
-    typealias TalkPageResult = Result<(articleSummary: WMFArticle?, items: [TalkPageItem]), Error>
+    typealias TalkPageResult = Result<(articleSummary: WMFArticle?, items: [TalkPageItem], subscribedTopicNames: [String]), Error>
 
     func fetchTalkPage(completion: @escaping (TalkPageResult) -> Void) {
 
@@ -31,6 +31,7 @@ class TalkPageDataController {
         var finalErrors: [Error] = []
         var finalItems: [TalkPageItem] = []
         var finalArticleSummary: WMFArticle?
+        var finalSubscribedTopics: [String] = []
 
         fetchTalkPageItems(dispatchGroup: group) { items, errors in
             finalItems = items
@@ -42,15 +43,21 @@ class TalkPageDataController {
             finalErrors.append(contentsOf: errors)
         }
 
+
         group.notify(queue: DispatchQueue.main, execute: {
 
             if let firstError = finalErrors.first {
                 completion(.failure(firstError))
                 return
             }
-
-            completion(.success((finalArticleSummary, finalItems)))
+            self.fetchTopicSubscriptions(for: finalItems, dispatchGroup: group) { items, errors in
+                finalSubscribedTopics = items
+                finalErrors.append(contentsOf: errors)
+                completion(.success((finalArticleSummary, finalItems, finalSubscribedTopics)))
+            }
+
         })
+
     }
 
     func postReply(commentId: String, comment: String, completion: @escaping(Result<Void, Error>) -> Void) {
@@ -72,22 +79,40 @@ class TalkPageDataController {
     }
 
     func subscribeToTopic(topicName: String, shouldSubscribe: Bool, completion: @escaping (Result<Bool, Error>) -> Void) {
-        talkPageFetcher.subscribeToTopic(talkPageTitle: pageTitle, siteURL: siteURL, topic: topicName, shouldSubscribe: shouldSubscribe, completion: completion)
-    }
-
-    func fetchSubscriptions(for topics: [String], completion: @escaping (Result<[String], Error>) -> Void) {
-        talkPageFetcher.getSubscribedTopics(siteURL: siteURL, topics: topics) { result in
-            switch result {
-            case let .success(result):
-                completion(.success(result))
-            case let .failure(error):
-                completion(.failure(error))
+
+        talkPageFetcher.subscribeToTopic(talkPageTitle: pageTitle, siteURL: siteURL, topic: topicName, shouldSubscribe: shouldSubscribe) { result in 
+            DispatchQueue.main.async {
+                completion(result)
             }
         }
     }
 
     // MARK: Private
 
+    private func fetchTopicSubscriptions(for items: [TalkPageItem], dispatchGroup group: DispatchGroup, completion: @escaping  ([String], [Error]) -> Void) {
+
+        var topicNames = [String]()
+        for item in items {
+            if let itemName = item.name {
+                topicNames.append(itemName)
+            }
+        }
+
+
+        talkPageFetcher.getSubscribedTopics(siteURL: siteURL, topics: topicNames) { result in
+
+            DispatchQueue.main.async {
+                switch result {
+                case let .success(result):
+                    completion(result, [])
+                case let .failure(error):
+                    completion([], [error])
+                }
+            }
+
+        }
+    }
+
     private func fetchTalkPageItems(dispatchGroup group: DispatchGroup, completion: @escaping ([TalkPageItem], [Error]) -> Void) {
 
         group.enter()

Wikipedia/Code/TalkPageFetcher.swift

@@ -145,6 +145,11 @@ class TalkPageFetcher: Fetcher {
         }
     }
 
+    /// Returns a list of active talk page topics subscription
+    /// - Parameters:
+    ///   - siteURL: URL for the talk page, takes a URL object
+    ///   - topics: Expects a array of Strings containing the `name` value from `TalkPageItem`
+    ///   - completion: Returns either and array with the the `name` property of subscribed topics or an Error
     func getSubscribedTopics(siteURL: URL, topics: [String], completion: @escaping (Result<[String], Error>) -> Void) {
 
         let joinedString = topics.joined(separator: "|")

Wikipedia/Code/TalkPageViewController.swift

@@ -368,9 +368,25 @@ extension TalkPageViewController: TalkPageCellDelegate {
         }
 
         let configuredCellViewModel = viewModel.topics[indexOfConfiguredCell]
-        configuredCellViewModel.isSubscribed.toggle()
+
+        let shouldSubscribe = !configuredCellViewModel.isSubscribed
+        cellViewModel.isSubscribed.toggle()
         cell.configure(viewModel: configuredCellViewModel, linkDelegate: self)
-        self.handleSubscriptionAlert(isSubscribedToTopic: configuredCellViewModel.isSubscribed)
+
+        viewModel.subscribe(to: configuredCellViewModel.topicName, shouldSubscribe: shouldSubscribe) { result in
+            switch result {
+            case let .success(didSubscribe):
+                self.handleSubscriptionAlert(isSubscribedToTopic: didSubscribe)
+            case let .failure(error):
+                cellViewModel.isSubscribed.toggle()
+                if cell.viewModel?.topicName == cellViewModel.topicName {
+                    cell.configure(viewModel: cellViewModel, linkDelegate: self)
+                }
+                DDLogError("Error subscribing to topic: \(error)")
+                // TODO: Error handling
+            }
+        }
+
     }
 }
 

Wikipedia/Code/TalkPageViewModel.swift

@@ -76,6 +76,7 @@ final class TalkPageViewModel {
                 let oldViewModels: [TalkPageCellViewModel] = self.topics
                 self.topics.removeAll()
                 self.populateCellData(topics: result.items, oldViewModels: oldViewModels)
+                self.updateSubscriptionForTopic(topicNames: result.subscribedTopicNames)
                 completion(.success(()))
             case .failure(let error):
                 DDLogError("Failure fetching talk page: \(error)")
@@ -84,27 +85,35 @@ final class TalkPageViewModel {
             }
         }
     }
-    
+
     func postTopic(topicTitle: String, topicBody: String, completion: @escaping(Result<Void, Error>) -> Void) {
         dataController.postTopic(topicTitle: topicTitle, topicBody: topicBody, completion: completion)
     }
 
+    func postReply(commentId: String, comment: String, completion: @escaping(Result<Void, Error>) -> Void) {
+        dataController.postReply(commentId: commentId, comment: comment, completion: completion)
+    }
+
 
-    func updateSubscriptionToTopic(topic: String, shouldSubscribe: Bool, completion: @escaping (Result<Bool, Error>) -> Void) {
-        dataController.subscribeToTopic(topicName: topic, shouldSubscribe: shouldSubscribe) { [self] result in
+    func subscribe(to topic: String, shouldSubscribe: Bool, completion: @escaping (Result<Bool, Error>) -> Void) {
+        dataController.subscribeToTopic(topicName: topic, shouldSubscribe: shouldSubscribe) { result in
             switch result {
             case let .success(result) :
-                let topicUpdated = topics.filter { $0.topicTitle == topic}
-                topicUpdated[0].isSubscribed = result
                 completion(.success(result))
             case let .failure(error):
                 completion(.failure(error))
             }
         }
     }
 
-    func postReply(commentId: String, comment: String, completion: @escaping(Result<Void, Error>) -> Void) {
-        dataController.postReply(commentId: commentId, comment: comment, completion: completion)
+    func updateSubscriptionForTopic(topicNames: [String]) {
+        for topic in topics {
+            for id in topicNames {
+                if topic.topicName == id {
+                    topic.isSubscribed = true
+                }
+            }
+        }
     }
 
     // MARK: - Private
@@ -166,8 +175,13 @@ final class TalkPageViewModel {
 
             let activeUsersCount = activeUsersCount(topic: topic)
 
-            let topicViewModel = TalkPageCellViewModel(id: topic.id, topicTitle: topicTitle, timestamp: firstReply.timestamp, leadComment: leadCommentViewModel, replies: remainingCommentViewModels, activeUsersCount: activeUsersCount, isUserLoggedIn: isUserLoggedIn)
-
+            guard let topicName = topic.name else {
+                DDLogError("Unable to parse topic name")
+                continue
+            }
+
+            let topicViewModel = TalkPageCellViewModel(id: topic.id, topicTitle: topicTitle, timestamp: firstReply.timestamp, topicName: topicName, leadComment: leadCommentViewModel, replies: remainingCommentViewModels, activeUsersCount: activeUsersCount, isUserLoggedIn: isUserLoggedIn)
+
             // Note this is a nested loop, so it will not perform well with many topics.
             // Talk pages generally have a limited number of topics, so optimize later if we determine it's needed
             assignExpandedFlag(to: topicViewModel, from: oldViewModels)