From 64effb46792dc20ab7966e7a221331123cce5a2e Mon Sep 17 00:00:00 2001
From: infinite-persistence <inf.persistence@gmail.com>
Date: Mon, 20 Sep 2021 10:30:23 +0800
Subject: [PATCH] doFetchActiveLivestreams: add interval and options checking

- Added a default minimum of 5 minutes between fetches. Clients can bypass this through `forceFetch` if needed.
- We'll need to support different 'orderBy', so adding an "options check" when determining if we just made the same fetch.
---
 flow-typed/livestream.js        |  2 ++
 ui/constants/action_types.js    |  1 +
 ui/redux/actions/livestream.js  | 49 +++++++++++++++++++++------------
 ui/redux/reducers/livestream.js | 12 ++++++--
 4 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/flow-typed/livestream.js b/flow-typed/livestream.js
index 63f1dd6a7..9bee62676 100644
--- a/flow-typed/livestream.js
+++ b/flow-typed/livestream.js
@@ -26,6 +26,8 @@ declare type LivestreamState = {
   viewersById: {},
   fetchingActiveLivestreams: boolean,
   activeLivestreams: ?LivestreamInfo,
+  activeLivestreamsLastFetchedDate: number,
+  activeLivestreamsLastFetchedOptions: {},
 }
 
 declare type LivestreamInfo = {
diff --git a/ui/constants/action_types.js b/ui/constants/action_types.js
index 6baee5377..17748007e 100644
--- a/ui/constants/action_types.js
+++ b/ui/constants/action_types.js
@@ -354,4 +354,5 @@ export const FETCH_NO_SOURCE_CLAIMS_FAILED = 'FETCH_NO_SOURCE_CLAIMS_FAILED';
 export const VIEWERS_RECEIVED = 'VIEWERS_RECEIVED';
 export const FETCH_ACTIVE_LIVESTREAMS_STARTED = 'FETCH_ACTIVE_LIVESTREAMS_STARTED';
 export const FETCH_ACTIVE_LIVESTREAMS_FAILED = 'FETCH_ACTIVE_LIVESTREAMS_FAILED';
+export const FETCH_ACTIVE_LIVESTREAMS_SKIPPED = 'FETCH_ACTIVE_LIVESTREAMS_SKIPPED';
 export const FETCH_ACTIVE_LIVESTREAMS_COMPLETED = 'FETCH_ACTIVE_LIVESTREAMS_COMPLETED';
diff --git a/ui/redux/actions/livestream.js b/ui/redux/actions/livestream.js
index 9ab7051a4..3f94b5a4c 100644
--- a/ui/redux/actions/livestream.js
+++ b/ui/redux/actions/livestream.js
@@ -33,19 +33,34 @@ export const doFetchNoSourceClaims = (channelId: string) => async (dispatch: Dis
   }
 };
 
-export const doFetchActiveLivestreams = () => {
-  return async (dispatch: Dispatch) => {
-    dispatch({
-      type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_STARTED,
-    });
+const FETCH_ACTIVE_LIVESTREAMS_MIN_INTERVAL_MS = 5 * 60 * 1000;
+
+export const doFetchActiveLivestreams = (
+  orderBy: Array<string> = ['release_time'],
+  pageSize: number = 50,
+  forceFetch: boolean = false
+) => {
+  return async (dispatch: Dispatch, getState: GetState) => {
+    const state = getState();
+    const now = Date.now();
+    const timeDelta = now - state.livestream.activeLivestreamsLastFetchedDate;
+
+    const prevOptions = state.livestream.activeLivestreamsLastFetchedOptions;
+    const nextOptions = { page_size: pageSize, order_by: orderBy };
+    const sameOptions = JSON.stringify(prevOptions) === JSON.stringify(nextOptions);
+
+    if (!forceFetch && sameOptions && timeDelta < FETCH_ACTIVE_LIVESTREAMS_MIN_INTERVAL_MS) {
+      dispatch({ type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_SKIPPED });
+      return;
+    }
+
+    dispatch({ type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_STARTED });
 
     fetch(LIVESTREAM_LIVE_API)
       .then((res) => res.json())
       .then((res) => {
         if (!res.data) {
-          dispatch({
-            type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED,
-          });
+          dispatch({ type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED });
           return;
         }
 
@@ -64,11 +79,11 @@ export const doFetchActiveLivestreams = () => {
           // live. The UI usually just wants to report the latest claim, so we
           // query that store it in `latestClaimUri`.
           doClaimSearch({
-            page_size: 50,
+            page_size: nextOptions.page_size,
             has_no_source: true,
             channel_ids: Object.keys(activeLivestreams),
             claim_type: ['stream'],
-            order_by: ['release_time'], // **
+            order_by: nextOptions.order_by, // **
             limit_claims_per_channel: 1, // **
             no_totals: true,
           })
@@ -88,19 +103,19 @@ export const doFetchActiveLivestreams = () => {
 
             dispatch({
               type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_COMPLETED,
-              data: activeLivestreams,
+              data: {
+                activeLivestreams,
+                activeLivestreamsLastFetchedDate: now,
+                activeLivestreamsLastFetchedOptions: nextOptions,
+              },
             });
           })
           .catch(() => {
-            dispatch({
-              type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED,
-            });
+            dispatch({ type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED });
           });
       })
       .catch((err) => {
-        dispatch({
-          type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED,
-        });
+        dispatch({ type: ACTIONS.FETCH_ACTIVE_LIVESTREAMS_FAILED });
       });
   };
 };
diff --git a/ui/redux/reducers/livestream.js b/ui/redux/reducers/livestream.js
index 932be2cb9..7a5d8af84 100644
--- a/ui/redux/reducers/livestream.js
+++ b/ui/redux/reducers/livestream.js
@@ -7,6 +7,8 @@ const defaultState: LivestreamState = {
   viewersById: {},
   fetchingActiveLivestreams: false,
   activeLivestreams: null,
+  activeLivestreamsLastFetchedDate: 0,
+  activeLivestreamsLastFetchedOptions: {},
 };
 
 export default handleActions(
@@ -45,8 +47,14 @@ export default handleActions(
       return { ...state, fetchingActiveLivestreams: false };
     },
     [ACTIONS.FETCH_ACTIVE_LIVESTREAMS_COMPLETED]: (state: LivestreamState, action: any) => {
-      const activeLivestreams: LivestreamInfo = action.data;
-      return { ...state, fetchingActiveLivestreams: false, activeLivestreams };
+      const { activeLivestreams, activeLivestreamsLastFetchedDate, activeLivestreamsLastFetchedOptions } = action.data;
+      return {
+        ...state,
+        fetchingActiveLivestreams: false,
+        activeLivestreams,
+        activeLivestreamsLastFetchedDate,
+        activeLivestreamsLastFetchedOptions,
+      };
     },
   },
   defaultState