From edd89450aa8a8e861544a53a27d94b8a9af22c3a Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sun, 4 Apr 2021 14:43:51 -0400
Subject: [PATCH] Fail gracefully when fetching statuses in timeline controller

---
 .../Timeline/TimelineTableViewController.swift    | 15 ++++++++++++---
 .../TimelineLikeTableViewController.swift         | 11 ++++++++++-
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/Tusker/Screens/Timeline/TimelineTableViewController.swift b/Tusker/Screens/Timeline/TimelineTableViewController.swift
index a28fd626..b2905246 100644
--- a/Tusker/Screens/Timeline/TimelineTableViewController.swift
+++ b/Tusker/Screens/Timeline/TimelineTableViewController.swift
@@ -72,7 +72,10 @@ class TimelineTableViewController: TimelineLikeTableViewController<TimelineEntry
         let request = Client.getStatuses(timeline: timeline)
         
         mastodonController?.run(request) { (response) in
-            guard case let .success(statuses, pagination) = response else { fatalError() }
+            guard case let .success(statuses, pagination) = response else {
+                completion([])
+                return
+            }
             
             self.newer = pagination?.newer
             self.older = pagination?.older
@@ -92,7 +95,10 @@ class TimelineTableViewController: TimelineLikeTableViewController<TimelineEntry
         let request = Client.getStatuses(timeline: timeline, range: older)
         
         mastodonController.run(request) { (response) in
-            guard case let .success(statuses, pagination) = response else { fatalError() }
+            guard case let .success(statuses, pagination) = response else {
+                completion([])
+                return
+            }
             
             self.older = pagination?.older
             
@@ -111,7 +117,10 @@ class TimelineTableViewController: TimelineLikeTableViewController<TimelineEntry
         let request = Client.getStatuses(timeline: timeline, range: newer)
         
         mastodonController.run(request) { (response) in
-            guard case let .success(statuses, pagination) = response else { fatalError() }
+            guard case let .success(statuses, pagination) = response else {
+                completion([])
+                return
+            }
             
             // if there are no new statuses, pagination is nil
             // if we were to then overwrite self.newer, future refreshes would fail
diff --git a/Tusker/Screens/Utilities/TimelineLikeTableViewController.swift b/Tusker/Screens/Utilities/TimelineLikeTableViewController.swift
index 1cfa7fdd..eb999268 100644
--- a/Tusker/Screens/Utilities/TimelineLikeTableViewController.swift
+++ b/Tusker/Screens/Utilities/TimelineLikeTableViewController.swift
@@ -65,11 +65,18 @@ class TimelineLikeTableViewController<Item>: EnhancedTableViewController, Refres
     
     func loadInitial() {
         guard !loaded else { return }
+        // set loaded immediately so we don't trigger another request while the current one is running
         loaded = true
         
         loadInitialItems() { (items) in
-            guard items.count > 0 else { return }
             DispatchQueue.main.async {
+                guard items.count > 0 else {
+                    // set loaded back to false so the next time the VC appears, we try to load again
+                    // todo: this should probably retry automatically
+                    self.loaded = false
+                    return
+                }
+                
                 if self.sections.count < self.headerSectionsCount() {
                     self.sections.insert(contentsOf: Array(repeating: [], count: self.headerSectionsCount() - self.sections.count), at: 0)
                 }
@@ -97,6 +104,8 @@ class TimelineLikeTableViewController<Item>: EnhancedTableViewController, Refres
         return "Refresh"
     }
     
+    // todo: these three should use Result<[Item], Client.Error> so we can differentiate between failed requests and there actually being no results
+    
     func loadInitialItems(completion: @escaping ([Item]) -> Void) {
         fatalError("loadInitialItems(completion:) must be implemented by subclasses")
     }