Allow clients to fetch statuses made while they were offline (#6876)

1 files changed, 29 insertions, 36 deletions

diff --git a/app/javascript/mastodon/reducers/timelines.js b/app/javascript/mastodon/reducers/timelines.js
index 9a10bcc59..f795e7e08 100644
--- a/app/javascript/mastodon/reducers/timelines.js
+++ b/app/javascript/mastodon/reducers/timelines.js
@@ -1,14 +1,10 @@
 import {
-  TIMELINE_REFRESH_REQUEST,
-  TIMELINE_REFRESH_SUCCESS,
-  TIMELINE_REFRESH_FAIL,
   TIMELINE_UPDATE,
   TIMELINE_DELETE,
   TIMELINE_EXPAND_SUCCESS,
   TIMELINE_EXPAND_REQUEST,
   TIMELINE_EXPAND_FAIL,
   TIMELINE_SCROLL_TOP,
-  TIMELINE_CONNECT,
   TIMELINE_DISCONNECT,
 } from '../actions/timelines';
 import {
@@ -22,37 +18,33 @@ const initialState = ImmutableMap();
 
 const initialTimeline = ImmutableMap({
   unread: 0,
-  online: false,
   top: true,
-  loaded: false,
   isLoading: false,
-  next: false,
+  hasMore: true,
   items: ImmutableList(),
 });
 
-const normalizeTimeline = (state, timeline, statuses, next, isPartial) => {
-  const oldIds    = state.getIn([timeline, 'items'], ImmutableList());
-  const ids       = ImmutableList(statuses.map(status => status.get('id'))).filter(newId => !oldIds.includes(newId));
-  const wasLoaded = state.getIn([timeline, 'loaded']);
-  const hadNext   = state.getIn([timeline, 'next']);
-
-  return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
-    mMap.set('loaded', true);
-    mMap.set('isLoading', false);
-    if (!hadNext) mMap.set('next', next);
-    mMap.set('items', wasLoaded ? ids.concat(oldIds) : oldIds.concat(ids));
-    mMap.set('isPartial', isPartial);
-  }));
-};
-
-const appendNormalizedTimeline = (state, timeline, statuses, next) => {
-  const oldIds = state.getIn([timeline, 'items'], ImmutableList());
-  const ids    = ImmutableList(statuses.map(status => status.get('id'))).filter(newId => !oldIds.includes(newId));
-
+const expandNormalizedTimeline = (state, timeline, statuses, next, isPartial) => {
   return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
     mMap.set('isLoading', false);
-    mMap.set('next', next);
-    mMap.set('items', oldIds.concat(ids));
+    if (!next) mMap.set('hasMore', false);
+
+    if (!statuses.isEmpty()) {
+      mMap.update('items', ImmutableList(), oldIds => {
+        const newIds = statuses.map(status => status.get('id'));
+        const lastIndex = oldIds.findLastIndex(id => id !== null && id >= newIds.last()) + 1;
+        const firstIndex = oldIds.take(lastIndex).findLastIndex(id => id !== null && id > newIds.first());
+
+        if (firstIndex < 0) {
+          return (isPartial ? newIds.unshift(null) : newIds).concat(oldIds.skip(lastIndex));
+        }
+
+        return oldIds.take(firstIndex + 1).concat(
+          isPartial && oldIds.get(firstIndex) !== null ? newIds.unshift(null) : newIds,
+          oldIds.skip(lastIndex)
+        );
+      });
+    }
   }));
 };
 
@@ -118,16 +110,12 @@ const updateTop = (state, timeline, top) => {
 
 export default function timelines(state = initialState, action) {
   switch(action.type) {
-  case TIMELINE_REFRESH_REQUEST:
   case TIMELINE_EXPAND_REQUEST:
     return state.update(action.timeline, initialTimeline, map => map.set('isLoading', true));
-  case TIMELINE_REFRESH_FAIL:
   case TIMELINE_EXPAND_FAIL:
     return state.update(action.timeline, initialTimeline, map => map.set('isLoading', false));
-  case TIMELINE_REFRESH_SUCCESS:
-    return normalizeTimeline(state, action.timeline, fromJS(action.statuses), action.next, action.partial);
   case TIMELINE_EXPAND_SUCCESS:
-    return appendNormalizedTimeline(state, action.timeline, fromJS(action.statuses), action.next);
+    return expandNormalizedTimeline(state, action.timeline, fromJS(action.statuses), action.next, action.partial);
   case TIMELINE_UPDATE:
     return updateTimeline(state, action.timeline, fromJS(action.status));
   case TIMELINE_DELETE:
@@ -139,10 +127,15 @@ export default function timelines(state = initialState, action) {
     return filterTimeline('home', state, action.relationship, action.statuses);
   case TIMELINE_SCROLL_TOP:
     return updateTop(state, action.timeline, action.top);
-  case TIMELINE_CONNECT:
-    return state.update(action.timeline, initialTimeline, map => map.set('online', true));
   case TIMELINE_DISCONNECT:
-    return state.update(action.timeline, initialTimeline, map => map.set('online', false));
+    return state.update(
+      action.timeline,
+      initialTimeline,
+      map => map.update(
+        'items',
+        items => items.first() ? items : items.unshift(null)
+      )
+    );
   default:
     return state;
   }