Added UI to show the progress on fetching online content.

* Refactored the viewModel code to show the downloading updates, e.g. content is fetching, downloading the online content, etc.

app/src/main/java/org/kiwix/kiwixmobile/nav/destination/library/OnlineLibraryFragment.kt

@@ -195,6 +195,13 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
         showInternetAccessViaMobileNetworkDialog()
       }
     }
+    zimManageViewModel.downloadProgress.observe(viewLifecycleOwner) { progress ->
+      fragmentDestinationDownloadBinding?.onlineLibraryProgressBar?.progress = progress
+    }
+
+    zimManageViewModel.downloadStatus.observe(viewLifecycleOwner) { status ->
+      fragmentDestinationDownloadBinding?.libraryErrorText?.text = status
+    }
     setupMenu()
 
     // hides keyboard when scrolled
@@ -268,6 +275,7 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
       libraryErrorText.visibility = View.GONE
       libraryList.visibility = View.VISIBLE
     }
+    showProgressBarOfFetchingOnlineLibrary()
   }
 
   private fun hideRecyclerviewAndShowSwipeDownForLibraryErrorText() {
@@ -277,6 +285,17 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
       )
       libraryErrorText.visibility = View.VISIBLE
       libraryList.visibility = View.GONE
+      onlineLibraryProgressBar.visibility = View.GONE
+    }
+  }
+
+  private fun showProgressBarOfFetchingOnlineLibrary() {
+    fragmentDestinationDownloadBinding?.apply {
+      onlineLibraryProgressBar.visibility = View.VISIBLE
+      libraryErrorText.apply {
+        visibility = View.VISIBLE
+        setText(string.reaching_remote_library)
+      }
     }
   }
 
@@ -345,6 +364,7 @@ class OnlineLibraryFragment : BaseFragment(), FragmentActivityExtensions {
     if (it != null) {
       libraryAdapter.items = it
     }
+    fragmentDestinationDownloadBinding?.onlineLibraryProgressBar?.visibility = View.GONE
     if (it?.isEmpty() == true) {
       fragmentDestinationDownloadBinding?.libraryErrorText?.setText(
         if (isNotConnected) string.no_network_connection

app/src/main/java/org/kiwix/kiwixmobile/zimManager/AppProgressListenerProvider.kt

@@ -0,0 +1,31 @@
+/*
+ * Kiwix Android
+ * Copyright (c) 2024 Kiwix <android.kiwix.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.kiwix.kiwixmobile.zimManager
+
+import org.kiwix.kiwixmobile.core.data.remote.OnlineLibraryProgressListener
+
+class AppProgressListenerProvider(
+  private val zimManageViewModel: ZimManageViewModel
+) : OnlineLibraryProgressListener {
+  @Suppress("MagicNumber")
+  override fun onProgress(bytesRead: Long, contentLength: Long, done: Boolean) {
+    val progress = if (contentLength == -1L) 0 else (bytesRead * 100 / contentLength).toInt()
+    zimManageViewModel.downloadProgress.postValue(progress)
+  }
+}

app/src/main/java/org/kiwix/kiwixmobile/zimManager/ZimManageViewModel.kt

@@ -33,6 +33,11 @@ import io.reactivex.plugins.RxJavaPlugins
 import io.reactivex.processors.BehaviorProcessor
 import io.reactivex.processors.PublishProcessor
 import io.reactivex.schedulers.Schedulers
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import okhttp3.logging.HttpLoggingInterceptor.Level.BASIC
+import okhttp3.logging.HttpLoggingInterceptor.Level.NONE
+import org.kiwix.kiwixmobile.BuildConfig.DEBUG
 import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.StorageObserver
 import org.kiwix.kiwixmobile.core.base.SideEffect
@@ -42,6 +47,13 @@ import org.kiwix.kiwixmobile.core.dao.NewBookDao
 import org.kiwix.kiwixmobile.core.dao.NewLanguagesDao
 import org.kiwix.kiwixmobile.core.data.DataSource
 import org.kiwix.kiwixmobile.core.data.remote.KiwixService
+import org.kiwix.kiwixmobile.core.data.remote.ProgressResponseBody
+import org.kiwix.kiwixmobile.core.data.remote.UserAgentInterceptor
+import org.kiwix.kiwixmobile.core.di.modules.CALL_TIMEOUT
+import org.kiwix.kiwixmobile.core.di.modules.CONNECTION_TIMEOUT
+import org.kiwix.kiwixmobile.core.di.modules.KIWIX_DOWNLOAD_URL
+import org.kiwix.kiwixmobile.core.di.modules.READ_TIMEOUT
+import org.kiwix.kiwixmobile.core.di.modules.USER_AGENT
 import org.kiwix.kiwixmobile.core.downloader.model.DownloadModel
 import org.kiwix.kiwixmobile.core.entity.LibraryNetworkEntity
 import org.kiwix.kiwixmobile.core.entity.LibraryNetworkEntity.Book
@@ -81,6 +93,7 @@ import java.io.IOException
 import java.util.LinkedList
 import java.util.Locale
 import java.util.concurrent.TimeUnit.MILLISECONDS
+import java.util.concurrent.TimeUnit.SECONDS
 import javax.inject.Inject
 
 const val DEFAULT_PROGRESS = 0
@@ -92,7 +105,7 @@ class ZimManageViewModel @Inject constructor(
   private val bookDao: NewBookDao,
   private val languageDao: NewLanguagesDao,
   private val storageObserver: StorageObserver,
-  private val kiwixService: KiwixService,
+  private var kiwixService: KiwixService,
   private val context: Application,
   private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver,
   private val bookUtils: BookUtils,
@@ -127,12 +140,44 @@ class ZimManageViewModel @Inject constructor(
   val requestFiltering = BehaviorProcessor.createDefault("")
 
   private var compositeDisposable: CompositeDisposable? = CompositeDisposable()
+  val downloadProgress = MutableLiveData<Int>()
+  val downloadStatus = MutableLiveData<String>()
 
   init {
+    // add listener to retrofit to get updates of downloading online library
+    kiwixService = createKiwixServiceWithProgressListener()
     compositeDisposable?.addAll(*disposables())
     context.registerReceiver(connectivityBroadcastReceiver)
   }
 
+  private fun createKiwixServiceWithProgressListener(): KiwixService {
+    val customOkHttpClient = OkHttpClient().newBuilder()
+      .followRedirects(true)
+      .followSslRedirects(true)
+      .connectTimeout(CONNECTION_TIMEOUT, SECONDS)
+      .readTimeout(READ_TIMEOUT, SECONDS)
+      .callTimeout(CALL_TIMEOUT, SECONDS)
+      .addNetworkInterceptor(
+        HttpLoggingInterceptor().apply {
+          level = if (DEBUG) BASIC else NONE
+        }
+      )
+      .addNetworkInterceptor(UserAgentInterceptor(USER_AGENT))
+      .addNetworkInterceptor { chain ->
+        val originalResponse = chain.proceed(chain.request())
+        originalResponse.newBuilder()
+          .body(
+            ProgressResponseBody(
+              originalResponse.body!!,
+              AppProgressListenerProvider(this)
+            )
+          )
+          .build()
+      }
+      .build()
+    return KiwixService.ServiceCreator.newHackListService(customOkHttpClient, KIWIX_DOWNLOAD_URL)
+  }
+
   @VisibleForTesting
   fun onClearedExposed() {
     onCleared()
@@ -232,7 +277,7 @@ class ZimManageViewModel @Inject constructor(
   }
 
   private fun requestsAndConnectivtyChangesToLibraryRequests(
-    library: PublishProcessor<LibraryNetworkEntity>
+    library: PublishProcessor<LibraryNetworkEntity>,
   ) =
     Flowable.combineLatest(
       requestDownloadLibrary,
@@ -254,21 +299,37 @@ class ZimManageViewModel @Inject constructor(
             .map { }
         }
       }
+      .doOnEach {
+        downloadStatus.postValue("Reaching remote library")
+      }
+      .switchMap {
+        Flowable.fromCallable {
+          downloadStatus.postValue("Starting download of the online library")
+        }
+      }
       .subscribeOn(Schedulers.io())
       .observeOn(Schedulers.io())
-      .subscribe(
-        {
-          compositeDisposable?.add(
+      .flatMap {
         kiwixService.library
+          .toFlowable()
           .retry(5)
-              .subscribe(library::onNext) {
-                it.printStackTrace()
-                library.onNext(LibraryNetworkEntity().apply { book = LinkedList() })
+          .doOnSubscribe {
+            downloadStatus.postValue("Downloading library 0%")
           }
-          )
-        },
-        Throwable::printStackTrace
-      )
+          .map { response ->
+            downloadStatus.postValue("Downloading library... parsing response")
+            response
+          }
+          .doFinally {
+            downloadStatus.postValue("Remote library downloaded, parsing data")
+          }
+          .onErrorReturn {
+            it.printStackTrace()
+            downloadStatus.postValue("Failed to download the library")
+            LibraryNetworkEntity().apply { book = LinkedList() }
+          }
+      }
+      .subscribe(library::onNext, Throwable::printStackTrace)
 
   private fun updateNetworkStates() =
     connectivityBroadcastReceiver.networkStates.subscribe(

app/src/main/res/layout/fragment_destination_download.xml

@@ -66,4 +66,13 @@
     app:layout_constraintVertical_bias="0.45"
     tools:ignore="RequiredSize" />
 
+  <ProgressBar
+    android:id="@+id/onlineLibraryProgressBar"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    app:layout_constraintStart_toStartOf="parent"
+    app:layout_constraintEnd_toEndOf="parent"
+    android:visibility="gone"
+    app:layout_constraintBottom_toTopOf="@+id/libraryErrorText" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>

core/src/main/java/org/kiwix/kiwixmobile/core/data/remote/OnlineLibraryProgressListener.kt

@@ -0,0 +1,23 @@
+/*
+ * Kiwix Android
+ * Copyright (c) 2024 Kiwix <android.kiwix.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.kiwix.kiwixmobile.core.data.remote
+
+interface OnlineLibraryProgressListener {
+  fun onProgress(bytesRead: Long, contentLength: Long, done: Boolean)
+}

core/src/main/java/org/kiwix/kiwixmobile/core/data/remote/ProgressResponseBody.kt

@@ -0,0 +1,72 @@
+/*
+ * Kiwix Android
+ * Copyright (c) 2024 Kiwix <android.kiwix.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.kiwix.kiwixmobile.core.data.remote
+
+import okhttp3.MediaType
+import okhttp3.ResponseBody
+import okio.Buffer
+import okio.BufferedSource
+import okio.ForwardingSource
+import okio.Source
+import okio.buffer
+import org.kiwix.kiwixmobile.core.utils.files.Log
+
+class ProgressResponseBody(
+  private val responseBody: ResponseBody,
+  private val progressListener: OnlineLibraryProgressListener
+) : ResponseBody() {
+
+  private var bufferedSource: BufferedSource? = null
+
+  override fun contentType(): MediaType? = responseBody.contentType()
+
+  override fun contentLength(): Long = responseBody.contentLength()
+
+  @Suppress("UnsafeCallOnNullableType")
+  override fun source(): BufferedSource {
+    if (bufferedSource == null) {
+      bufferedSource = source(responseBody.source()).buffer()
+    }
+    return bufferedSource!!
+  }
+
+  private fun source(source: Source): Source {
+    return object : ForwardingSource(source) {
+      var totalBytesRead = 0L
+      override fun read(sink: Buffer, byteCount: Long): Long {
+        val bytesRead = super.read(sink, byteCount)
+        totalBytesRead += if (bytesRead != -1L) bytesRead else 0
+        val isDone = bytesRead == -1L
+        progressListener.onProgress(
+          totalBytesRead,
+          responseBody.contentLength(),
+          isDone
+        ).also {
+          Log.e(
+            "PROGRESS",
+            "onProgress: ${contentLength()} and byteRead = $totalBytesRead\n" +
+              " sink ${bytesRead == -1L} \n byteRead = $bytesRead " +
+              "\n bufferedSource = ${bufferedSource?.isOpen}"
+          )
+        }
+        return bytesRead
+      }
+    }
+  }
+}

core/src/main/java/org/kiwix/kiwixmobile/core/di/modules/NetworkModule.kt

@@ -30,11 +30,11 @@ import org.kiwix.kiwixmobile.core.data.remote.UserAgentInterceptor
 import java.util.concurrent.TimeUnit.SECONDS
 import javax.inject.Singleton
 
-private const val CONNECTION_TIMEOUT = 10L
-private const val READ_TIMEOUT = 60L
-private const val CALL_TIMEOUT = 60L
-private const val USER_AGENT = "kiwix-android-version:${BuildConfig.VERSION_CODE}"
-private const val KIWIX_DOWNLOAD_URL = "https://mirror.download.kiwix.org/"
+const val CONNECTION_TIMEOUT = 10L
+const val READ_TIMEOUT = 60L
+const val CALL_TIMEOUT = 60L
+const val USER_AGENT = "kiwix-android-version:${BuildConfig.VERSION_CODE}"
+const val KIWIX_DOWNLOAD_URL = "https://mirror.download.kiwix.org/"
 
 @Module
 class NetworkModule {

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

@@ -348,6 +348,7 @@
   <string name="system_unable_to_grant_permission_message">System unable to grant permission!</string>
   <string name="allow">Allow</string>
   <string name="swipe_down_for_library">Swipe Down for Library</string>
+  <string name="reaching_remote_library">Reaching remote library</string>
   <string-array name="pref_dark_modes_entries">
     <item>@string/on</item>
     <item>@string/off</item>