Fix an issue with P2 sites and follow conversation (#24135)

* Fix an issue with P2 sites and follow conversation

* Update release notse

Author: kean

RELEASE-NOTES.txt

@@ -19,6 +19,8 @@
 * [*] Fix Reader Comments: Reply button is hidden when pasting long text (the ap now uses a sheet) [#17964]
 * [*] Fix Reader Comments: Cells could sometimes be displayed overlapping another cell [#17653]
 * [*] Fix Notifications: quote blocks in the Reply screen are not styled correctly [#13971]
+* [*] Fix an issue with "Follow Conversation" button not visible on some P2s [#24135]
+* [*] Fix an issue with "Enable Comments Notifications" button being visible and not working correctly on some P2s [#24135]
 * [*] Fix Notifications pointing to large threads sometimes break the app [#23993]
 * [*] Fix an issue with search results disappearing after returning from site details [#24121]
 * [*] Fix Reader: Opening comments is slow [#21887]

WordPress/Classes/Models/ReaderPost+Swift.swift

@@ -3,6 +3,21 @@ import WordPressUI
 
 extension ReaderPost {
 
+    /// - note: this is a workaround for https://github.com/wordpress-mobile/WordPress-iOS/issues/18975 and
+    /// https://github.com/wordpress-mobile/WordPress-iOS/issues/20953. This code
+    /// makes sure that you see the "Follow Conversation" button on P2s
+    /// but not if you have "Emails me all comments" option enabled, which
+    /// matches the behavior on the web.
+    var canActuallySubscribeToComments: Bool {
+        if canSubscribeComments {
+            return true
+        }
+        if isP2Type() {
+            return !((topic as? ReaderSiteTopic)?.emailSubscription?.sendComments ?? false)
+        }
+        return false
+    }
+
     func getSiteIconURL(size: Int) -> URL? {
         SiteIconViewModel.makeReaderSiteIconURL(iconURL: siteIconURL, siteID: siteID?.intValue, size: CGSize(width: size, height: size))
     }

WordPress/Classes/Services/FollowCommentsService.swift

@@ -35,7 +35,7 @@ class FollowCommentsService: NSObject {
     /// Returns a Bool indicating whether or not the comments on the post can be followed.
     ///
     @objc var canFollowConversation: Bool {
-        return post.canSubscribeComments
+        return post.canActuallySubscribeToComments
     }
 
     /// Fetches the subscription status of the specified post for the current user.

WordPress/Classes/ViewRelated/Reader/Detail/Views/ReaderDetailCommentsHeader.swift

@@ -46,7 +46,7 @@ class ReaderDetailCommentsHeader: UITableViewHeaderFooterView, NibReusable {
     ) {
         self.post = post
         self.totalComments = totalComments
-        self.followConversationEnabled = post.commentsOpen && post.canSubscribeComments
+        self.followConversationEnabled = post.commentsOpen && post.canActuallySubscribeToComments
         self.followButtonTappedClosure = followButtonTappedClosure
 
         configureTitle()