background fetch

Author: hyoban

apps/mobile/package.json

@@ -54,6 +54,7 @@
     "expo-apple-authentication": "7.1.3",
     "expo-application": "6.0.2",
     "expo-av": "15.0.2",
+    "expo-background-fetch": "13.0.6",
     "expo-blur": "14.0.3",
     "expo-build-properties": "0.13.2",
     "expo-clipboard": "7.0.1",
@@ -78,6 +79,7 @@
     "expo-status-bar": "2.0.1",
     "expo-symbols": "0.2.2",
     "expo-system-ui": "4.0.9",
+    "expo-task-manager": "12.0.6",
     "expo-updates": "0.27.4",
     "expo-web-browser": "14.0.2",
     "hono": "4.7.5",

apps/mobile/src/initialize/background.ts

@@ -0,0 +1,27 @@
+import * as BackgroundFetch from "expo-background-fetch"
+import * as TaskManager from "expo-task-manager"
+
+import { unreadSyncService } from "../store/unread/store"
+
+const BACKGROUND_FETCH_TASK = "background-fetch"
+
+export async function initBackgroundFetch() {
+  TaskManager.defineTask(BACKGROUND_FETCH_TASK, async () => {
+    // const now = Date.now()
+    // console.log(`Got background fetch call at date: ${new Date(now).toISOString()}`)
+
+    try {
+      const res = await unreadSyncService.updateBadgeAtBackground()
+      return res
+        ? BackgroundFetch.BackgroundFetchResult.NewData
+        : BackgroundFetch.BackgroundFetchResult.NoData
+    } catch (err) {
+      console.error(err)
+      return BackgroundFetch.BackgroundFetchResult.Failed
+    }
+  })
+
+  return BackgroundFetch.registerTaskAsync(BACKGROUND_FETCH_TASK, {
+    minimumInterval: 60 * 15, // 15 minutes
+  })
+}

apps/mobile/src/initialize/index.ts

@@ -4,6 +4,7 @@ import { nativeApplicationVersion } from "expo-application"
 import { initializeDb } from "../database"
 import { initAnalytics } from "./analytics"
 import { initializeAppCheck } from "./app-check"
+import { initBackgroundFetch } from "./background"
 import { initCrashlytics } from "./crashlytics"
 import { initializeDayjs } from "./dayjs"
 import { hydrateDatabaseToStore, hydrateQueryClient, hydrateSettings } from "./hydrate"
@@ -40,6 +41,7 @@ export const initializeApp = async () => {
     using_indexed_db: true,
   })
   initCrashlytics()
+  initBackgroundFetch()
   console.log(`Initialize done,`, `${loadingTime}ms`)
 }
 

apps/mobile/src/store/unread/getter.ts

@@ -4,3 +4,8 @@ export const getUnreadCount = (id: string) => {
   const state = useUnreadStore.getState()
   return state.data[id] ?? 0
 }
+
+export const getAllUnreadCount = () => {
+  const state = useUnreadStore.getState()
+  return Object.values(state.data).reduce((acc, unread) => acc + unread, 0)
+}

apps/mobile/src/store/unread/store.ts

@@ -1,4 +1,5 @@
 import type { FeedViewType } from "@follow/constants"
+import * as Notifications from "expo-notifications"
 
 import type { UnreadSchema } from "@/src/database/schemas/types"
 import { apiClient } from "@/src/lib/api-fetch"
@@ -9,6 +10,7 @@ import { getEntry } from "../entry/getter"
 import { entryActions } from "../entry/store"
 import { createTransaction, createZustandStore } from "../internal/helper"
 import { getSubscriptionByView } from "../subscription/getter"
+import { getAllUnreadCount } from "./getter"
 
 type SubscriptionId = string
 interface UnreadStore {
@@ -30,6 +32,17 @@ class UnreadSyncService {
     return res.data
   }
 
+  async updateBadgeAtBackground() {
+    await this.fetch()
+    const allUnreadCount = getAllUnreadCount()
+    const currentBadgeCount = await Notifications.getBadgeCountAsync()
+    if (allUnreadCount === currentBadgeCount) {
+      return false
+    }
+    await Notifications.setBadgeCountAsync(allUnreadCount)
+    return true
+  }
+
   private async updateUnreadStatus(feedIds: string[]) {
     await unreadActions.upsertMany(feedIds.map((id) => ({ subscriptionId: id, count: 0 })))
     entryActions.markEntryReadStatusInSession({ feedIds, read: true })