presence: Use server-provided params in the webapp.

As of the previous commit, the server provides these parameters in
page_params. The defaults match the values hard-coded in the webapp so
far - so get rid of the hard-coded values in favor of taking them from
page_params.

frontend_tests/node_tests/activity.js

@@ -577,6 +577,8 @@ test("update_presence_info", ({override}) => {
     override(pm_list, "update_private_messages", () => {});
 
     page_params.realm_presence_disabled = false;
+    page_params.server_presence_ping_interval_seconds = 50;
+    page_params.server_presence_offline_threshold_seconds = 140;
 
     const server_time = 500;
     const info = {

frontend_tests/node_tests/buddy_data.js

@@ -422,6 +422,8 @@ test("always show me", () => {
 });
 
 test("level", () => {
+    page_params.server_presence_offline_threshold_seconds = 140;
+
     add_canned_users();
     assert.equal(buddy_data.level(me.user_id), 0);
     assert.equal(buddy_data.level(selma.user_id), 3);

frontend_tests/node_tests/presence.js

@@ -5,7 +5,7 @@ const {strict: assert} = require("assert");
 const {mock_esm, zrequire} = require("../zjsunit/namespace");
 const {run_test} = require("../zjsunit/test");
 const blueslip = require("../zjsunit/zblueslip");
-const {user_settings} = require("../zjsunit/zpage_params");
+const {page_params, user_settings} = require("../zjsunit/zpage_params");
 
 const reload_state = mock_esm("../../static/js/reload_state", {
     is_in_progress: () => false,
@@ -78,6 +78,7 @@ people.initialize_current_user(me.user_id);
 
 function test(label, f) {
     run_test(label, ({override}) => {
+        page_params.server_presence_offline_threshold_seconds = OFFLINE_THRESHOLD_SECS;
         user_settings.presence_enabled = true;
         presence.clear_internal_data();
         f({override});

static/js/activity.js

@@ -27,8 +27,6 @@ export let user_filter;
 
 /* Broadcast "idle" to server after 5 minutes of local inactivity */
 const DEFAULT_IDLE_TIMEOUT_MS = 5 * 60 * 1000;
-/* Time between keep-alive pings */
-const ACTIVE_PING_INTERVAL_MS = 50 * 1000;
 
 /* Keep in sync with views.py:update_active_status_backend() */
 export const ACTIVE = "active";
@@ -246,7 +244,9 @@ export function initialize() {
         send_presence_to_server(true);
     }
 
-    util.call_function_periodically(get_full_presence_list_update, ACTIVE_PING_INTERVAL_MS);
+    /* Time between keep-alive pings */
+    const active_ping_interval_ms = page_params.server_presence_ping_interval_seconds * 1000;
+    util.call_function_periodically(get_full_presence_list_update, active_ping_interval_ms);
 
     // Let the server know we're here, but pass "false" for
     // want_redraw, since we just got all this info in page_params.

static/js/presence.js

@@ -1,4 +1,5 @@
 import * as blueslip from "./blueslip";
+import {page_params} from "./page_params";
 import * as people from "./people";
 import * as reload_state from "./reload_state";
 import {user_settings} from "./user_settings";
@@ -22,11 +23,6 @@ export function clear_internal_data() {
     presence_info.clear();
 }
 
-/* Mark users as offline after 140 seconds since their last checkin,
- * Keep in sync with zerver/tornado/event_queue.py:receiver_is_idle
- */
-const OFFLINE_THRESHOLD_SECS = 140;
-
 const BIG_REALM_COUNT = 250;
 
 export function get_status(user_id) {
@@ -58,6 +54,10 @@ export function status_from_raw(raw) {
             server_timestamp: 1585745140
         }
     */
+
+    /* Mark users as offline after this many seconds since their last checkin, */
+    const offline_threshold_secs = page_params.server_presence_offline_threshold_seconds;
+
     function age(timestamp) {
         return raw.server_timestamp - (timestamp || 0);
     }
@@ -79,14 +79,14 @@ export function status_from_raw(raw) {
         show the user as active (even if there's a newer
         timestamp for idle).
     */
-    if (age(active_timestamp) < OFFLINE_THRESHOLD_SECS) {
+    if (age(active_timestamp) < offline_threshold_secs) {
         return {
             status: "active",
             last_active,
         };
     }
 
-    if (age(idle_timestamp) < OFFLINE_THRESHOLD_SECS) {
+    if (age(idle_timestamp) < offline_threshold_secs) {
         return {
             status: "idle",
             last_active,

zproject/default_settings.py

@@ -488,7 +488,6 @@ LOG_API_EVENT_TYPES = False
 STAGING = False
 
 # How long to wait before presence should treat a user as offline.
-# Should match the presence.js constant.
 OFFLINE_THRESHOLD_SECS = 140
 
 # How often a client should ping by asking for presence data of all users.