feat: implement background fetch worker (cont.)

app/build.gradle

@@ -16,7 +16,7 @@ android {
 
     defaultConfig {
         applicationId "io.github.kabirnayeem99.islamqaorg"
-        minSdk 26
+        minSdk 29
         targetSdk 34
         versionCode 1
         versionName "1.2.1-alpha"

app/src/main/AndroidManifest.xml

@@ -4,7 +4,8 @@
 
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.INTERNET" />
-    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
 
     <application
         android:name=".common.base.IslamQaApp"
@@ -31,6 +32,11 @@
             android:exported="true"
             android:fitsSystemWindows="true" />
 
+        <service
+            android:name="androidx.work.impl.foreground.SystemForegroundService"
+            android:foregroundServiceType="dataSync"
+            tools:node="merge" />
+
         <provider
             android:name="androidx.startup.InitializationProvider"
             android:authorities="${applicationId}.androidx-startup"

app/src/main/java/io/github/kabirnayeem99/islamqaorg/data/dataSource/localDb/QuestionListDao.kt

@@ -43,7 +43,7 @@ interface QuestionListDao {
      * Returns a list of QuestionEntity objects, ordered by timeInMillis in descending order, and
      * limited to 10 items
      */
-    @Query("SELECT * FROM questionentity ORDER BY timeInMillis desc LIMIT 10")
+    @Query("SELECT * FROM questionentity ORDER BY RANDOM() desc LIMIT 10")
     suspend fun getRandomQuestions(): List<QuestionEntity>
 
 //    @Query("SELECT * FROM questionentity WHERE question LIKE '%' || :query || '%' ORDER BY timeInMillis desc LIMIT 10")

app/src/main/java/io/github/kabirnayeem99/islamqaorg/data/dataSource/service/ScrapingService.kt

@@ -110,8 +110,6 @@ class ScrapingService {
                         fiqh = getFiqhForQuestionDetails(),
                         source = getSourceForQuestionDetails(),
                         originalLink = link,
-                        nextQuestionLink = getPrevOrNextLink(Page.NEXT),
-                        previousQuestionLink = getPrevOrNextLink(Page.PREV),
                         relevantQuestions = getRelevantQuestionsFromQuestionDetails()
                     )
                 }

app/src/main/java/io/github/kabirnayeem99/islamqaorg/data/repository/QuestionAnswerRepositoryImpl.kt

@@ -11,13 +11,18 @@ import io.github.kabirnayeem99.islamqaorg.domain.entity.Fiqh
 import io.github.kabirnayeem99.islamqaorg.domain.entity.Question
 import io.github.kabirnayeem99.islamqaorg.domain.entity.QuestionDetail
 import io.github.kabirnayeem99.islamqaorg.domain.repository.QuestionAnswerRepository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import timber.log.Timber
 import javax.inject.Inject
+import kotlin.random.Random
 
 class QuestionAnswerRepositoryImpl
 @Inject constructor(
@@ -34,27 +39,19 @@ class QuestionAnswerRepositoryImpl
     private var inMemoryRandomQuestionList = emptyList<Question>()
 
     override suspend fun getRandomQuestionList(shouldRefresh: Boolean): Flow<List<Question>> {
-        val cachedRandomQuestionList = inMemoryMutex.withLock { inMemoryRandomQuestionList }
         return flow {
-            if (isNetworkAvailable) {
-                val remoteData = getRandomQuestionListFromRemoteDataSource()
-                emit(remoteData)
-            } else {
-                val localQuestionList = localDataSource.getRandomQuestionList()
-                if (localQuestionList.isEmpty()) {
-                    val remoteData = getRandomQuestionListFromRemoteDataSource()
-                    emit(remoteData)
-                }
-                inMemoryMutex.withLock { inMemoryRandomQuestionList = localQuestionList }
-                preferenceDataSource.updateNeedingToRefresh()
-                emit(localQuestionList)
-            }
+            val localQuestionList = localDataSource.getRandomQuestionList()
+            inMemoryRandomQuestionList = localQuestionList
+            emit(localQuestionList)
         }.onStart {
-            if (cachedRandomQuestionList.isNotEmpty()) emit(cachedRandomQuestionList)
-        }
+            if (inMemoryRandomQuestionList.isNotEmpty()) emit(inMemoryRandomQuestionList)
+        }.catch { e ->
+            Timber.e(e, "getRandomQuestionList: ")
+            emit(inMemoryFiqhBasedQuestionList)
+        }.flowOn(Dispatchers.IO)
     }
 
-    override suspend fun fetchAndSaveRandomQuestionList(): Boolean {
+    override suspend fun fetchAndSaveQuestionListByFiqh(setProgress: suspend (Int) -> Unit): Boolean {
         try {
             val fiqh = getCurrentlySelectedFiqh()
             val lastSyncedPage = preferenceDataSource.getCurrentFiqhLastPageSynced()
@@ -66,6 +63,11 @@ class QuestionAnswerRepositoryImpl
                     throw IllegalStateException("Failed with page $page for fiqh ${fiqh.displayName}")
                 } else {
                     localDataSource.cacheQuestionList(list)
+                    list.forEachIndexed { index, q ->
+                        delay(Random.nextLong(q.url.length.toLong()))
+                        getAndCacheQuestionDetailFromRemote(q.url)
+                        setProgress(((page + 1) - newStartingPage) * (index + 1))
+                    }
                     preferenceDataSource.saveCurrentFiqhLastPageSynced(newLastSyncingPage)
                     Timber.i("fetchAndSaveRandomQuestionList: saved page $page for fiqh ${fiqh.displayName}")
                 }
@@ -95,7 +97,6 @@ class QuestionAnswerRepositoryImpl
 
     override suspend fun getQuestionDetails(url: String): Flow<QuestionDetail> {
         val inMemoryQuestionDetail = inMemoryQuestionDetails.get(url) ?: QuestionDetail()
-
         return flow {
             try {
                 val questionDetailLocal = localDataSource.getDetailedQuestionAndAnswer(url)

app/src/main/java/io/github/kabirnayeem99/islamqaorg/data/workers/BackgroundQAListFetcherWorker.kt

@@ -1,9 +1,14 @@
 package io.github.kabirnayeem99.islamqaorg.data.workers
 
+import android.app.NotificationChannel
+import android.app.NotificationManager
 import android.content.Context
+import android.content.pm.ServiceInfo
+import androidx.core.app.NotificationCompat
 import androidx.work.Constraints
 import androidx.work.CoroutineWorker
 import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.ForegroundInfo
 import androidx.work.ListenableWorker
 import androidx.work.NetworkType
 import androidx.work.PeriodicWorkRequest
@@ -12,6 +17,11 @@ import androidx.work.WorkerFactory
 import androidx.work.WorkerParameters
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedInject
+import io.github.kabirnayeem99.islamqaorg.R
+import io.github.kabirnayeem99.islamqaorg.data.dataSource.workers.CHANNEL_ID
+import io.github.kabirnayeem99.islamqaorg.data.dataSource.workers.NOTIFICATION_ID
+import io.github.kabirnayeem99.islamqaorg.data.dataSource.workers.SYNC_NOTIFICATION_CHANNEL_DESCRIPTION
+import io.github.kabirnayeem99.islamqaorg.data.dataSource.workers.SYNC_NOTIFICATION_CHANNEL_NAME
 import io.github.kabirnayeem99.islamqaorg.domain.repository.QuestionAnswerRepository
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
@@ -24,17 +34,53 @@ class BackgroundQAListFetcherWorker @AssistedInject constructor(
     @Assisted private val workerParams: WorkerParameters,
     private val questionAnswerRepository: QuestionAnswerRepository,
 ) : CoroutineWorker(appContext, workerParams) {
+
     override suspend fun doWork(): Result {
         return withContext(Dispatchers.IO) {
-            val successfullySynced = questionAnswerRepository.fetchAndSaveRandomQuestionList()
+            createChannel()
+            setForeground(createForegroundInfo(1))
+            val successfullySynced = questionAnswerRepository.fetchAndSaveQuestionListByFiqh { p ->
+                setForeground(createForegroundInfo(p))
+            }
             if (successfullySynced) Result.success() else Result.failure()
         }
     }
 
+
+    private fun createForegroundInfo(progress: Int): ForegroundInfo {
+        val title = applicationContext.getString(R.string.notification_title)
+        val cancel = applicationContext.getString(R.string.cancel_download)
+        val intent = WorkManager.getInstance(applicationContext).createCancelPendingIntent(id)
+        val progressText = "Loading questions: ${progress}%"
+        val notification =
+            NotificationCompat.Builder(applicationContext, CHANNEL_ID).setContentTitle(title)
+                .setTicker(title).setContentText(progressText).setSmallIcon(R.drawable.ic_islamqa)
+                .setOngoing(true).addAction(R.drawable.ic_arrow_forward, cancel, intent)
+                .setProgress(100, progress, false)
+                .build()
+        return ForegroundInfo(
+            NOTIFICATION_ID,
+            notification,
+            ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC
+        )
+    }
+
+    private fun createChannel() {
+        val name = SYNC_NOTIFICATION_CHANNEL_NAME
+        val description = SYNC_NOTIFICATION_CHANNEL_DESCRIPTION
+        val importance = NotificationManager.IMPORTANCE_LOW
+        val channel = NotificationChannel(CHANNEL_ID, name, importance)
+        channel.description = description
+        val notificationManager =
+            appContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager?
+        notificationManager?.createNotificationChannel(channel)
+    }
+
+
     companion object {
         private const val TAG = "BackgroundQAListFetcher"
         private const val SYNC_INTERVAL_HOURS = 4L
-         fun enqueue(workManager: WorkManager) {
+        fun enqueue(workManager: WorkManager) {
             try {
                 val constraintsBuilder = Constraints.Builder()
                 constraintsBuilder.apply {

app/src/main/java/io/github/kabirnayeem99/islamqaorg/domain/repository/QuestionAnswerRepository.kt

@@ -8,7 +8,7 @@ interface QuestionAnswerRepository {
 
     suspend fun getRandomQuestionList(shouldRefresh: Boolean = false): Flow<List<Question>>
 
-    suspend fun fetchAndSaveRandomQuestionList(): Boolean
+    suspend fun fetchAndSaveQuestionListByFiqh(setProgress: suspend (Int) -> Unit = {}): Boolean
 
     suspend fun getFiqhBasedQuestionList(
         pageNumber: Int, shouldRefresh: Boolean = false

app/src/main/res/values-night/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="notification_title">Syncing questions and answers</string>
+</resources>

app/src/main/res/values-v31/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="notification_title">Syncing questions and answers</string>
+</resources>

app/src/main/res/values/strings.xml

@@ -41,4 +41,6 @@
     <string name="label_syncing">We are syncing the questions and answers from IslamQA.org in the background. It will ensure faster loading, the next time you enter this app. It will also reduce load on the original website.</string>
     <string name="label_synced">We are done syncing. Note that, this app is just a frontend for IslamQA.org. Please, pray for the creator of this awesome website for their amazing work. Visit this website for any of your query.</string>
     <string name="content_desc_search">Search for questions</string>
+    <string name="notification_title">Syncing questions and answers</string>
+    <string name="cancel_download">Cancel syncing</string>
 </resources>