Refactored the code to not ask permission for custom apps while starting the hotspot since we do not required any permission for starting the server in custom apps.

* Fixed: ZIM file was not showing in the Hotspot screen.
* Removed the unnecessary code and creation of demo file for custom app.

core/src/main/java/org/kiwix/kiwixmobile/core/dao/NewBookDao.kt

@@ -26,9 +26,11 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.rx3.rxSingle
+import org.kiwix.kiwixmobile.core.CoreApp.Companion.instance
 import org.kiwix.kiwixmobile.core.dao.entities.BookOnDiskEntity
 import org.kiwix.kiwixmobile.core.dao.entities.BookOnDiskEntity_
 import org.kiwix.kiwixmobile.core.entity.LibraryNetworkEntity.Book
+import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.isCustomApp
 import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 import org.kiwix.kiwixmobile.core.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 import javax.inject.Inject
@@ -42,7 +44,6 @@ class NewBookDao @Inject constructor(private val box: Box<BookOnDiskEntity>) {
         .flatMapSingle { bookOnDiskEntity ->
           val file = bookOnDiskEntity.file
           val zimReaderSource = ZimReaderSource(file)
-
           rxSingle { zimReaderSource.canOpenInLibkiwix() }
             .map { canOpen ->
               if (canOpen) {
@@ -72,7 +73,8 @@ class NewBookDao @Inject constructor(private val box: Box<BookOnDiskEntity>) {
             }
         }
         .filter { (bookOnDiskEntity, exists) ->
-          exists && !isInTrashFolder(bookOnDiskEntity.zimReaderSource.toDatabase())
+          (instance.getMainActivity().isCustomApp() || exists) &&
+            !isInTrashFolder(bookOnDiskEntity.zimReaderSource.toDatabase())
         }
         .map(Pair<BookOnDiskEntity, Boolean>::first)
         .toList()
@@ -152,6 +154,7 @@ class NewBookDao @Inject constructor(private val box: Box<BookOnDiskEntity>) {
   }
 
   private suspend fun removeBooksThatDoNotExist(books: MutableList<BookOnDiskEntity>) {
+    if (instance.getMainActivity().isCustomApp()) return
     delete(books.filterNot { it.zimReaderSource.exists() })
   }
 

core/src/main/java/org/kiwix/kiwixmobile/core/utils/files/FileUtils.kt

@@ -593,10 +593,6 @@ object FileUtils {
     }
   }
 
-  @JvmStatic
-  fun getDemoFilePathForCustomApp(context: Context) =
-    "${context.getExternalFilesDirs(null)[0]}/demo.zim"
-
   @SuppressLint("Recycle")
   @JvmStatic
   fun getAssetFileDescriptorFromUri(
@@ -633,6 +629,10 @@ object FileUtils {
       // via the given file path before passing it to libkiwix.
       // This precaution helps prevent runtime crashes.
       // For more details, refer to https://github.com/kiwix/kiwix-android/pull/3636.
+      Log.e(
+        "CAN_OPEN_IN_LIBKIWIX",
+        "isFileDescriptorCanOpenWithLibkiwix: ${FileInputStream("dev/fd/$fdNumber")}"
+      )
       FileInputStream("dev/fd/$fdNumber")
       true
     } catch (ignore: Exception) {

core/src/main/java/org/kiwix/kiwixmobile/core/webserver/KiwixServer.kt

@@ -19,11 +19,15 @@
 package org.kiwix.kiwixmobile.core.webserver
 
 import android.content.Context
+import android.os.Looper
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
-import org.kiwix.kiwixmobile.core.utils.files.Log
+import org.kiwix.kiwixmobile.core.CoreApp
+import org.kiwix.kiwixmobile.core.extensions.ActivityExtensions.isCustomApp
 import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
-import org.kiwix.kiwixmobile.core.utils.files.FileUtils.getDemoFilePathForCustomApp
+import org.kiwix.kiwixmobile.core.utils.files.Log
 import org.kiwix.libkiwix.Book
 import org.kiwix.libkiwix.Library
 import org.kiwix.libkiwix.Server
@@ -44,29 +48,28 @@ class KiwixServer @Inject constructor(
     private val context: Context,
     private val zimReaderContainer: ZimReaderContainer
   ) {
-    @Suppress("NestedBlockDepth")
+    @Suppress("NestedBlockDepth", "MagicNumber")
     suspend fun createKiwixServer(selectedBooksPath: ArrayList<String>): KiwixServer =
       withContext(Dispatchers.IO) {
         val kiwixLibrary = Library()
         selectedBooksPath.forEach { path ->
           try {
             val book = Book().apply {
+              Log.e(
+                TAG,
+                " FD is valid = ${zimReaderContainer.zimReaderSource?.exists()} \n" +
+                  "FD can read via the dev/fd/fdNumber = " +
+                  "${zimReaderContainer.zimReaderSource?.canOpenInLibkiwix()}"
+              )
               // Determine whether to create an Archive from an asset or a file path
-              val archive = if (path == getDemoFilePathForCustomApp(context)) {
-                // For custom apps using a demo file, create an Archive with FileDescriptor
-                val assetFileDescriptor =
-                  zimReaderContainer.zimReaderSource?.assetFileDescriptorList?.get(0)
-                val startOffset = assetFileDescriptor?.startOffset ?: 0L
-                val size = assetFileDescriptor?.length ?: 0L
-                Archive(
-                  assetFileDescriptor?.parcelFileDescriptor?.fileDescriptor,
-                  startOffset,
-                  size
-                )
-              } else {
-                // For regular files, create an Archive from the file path
-                Archive(path)
-              }
+              val archive =
+                if (path == "null" && (context as CoreApp).getMainActivity().isCustomApp()) {
+                  // For custom apps using create an Archive with FileDescriptor
+                  zimReaderContainer.zimReaderSource?.createArchive()
+                } else {
+                  // For regular files, create an Archive from the file path
+                  Archive(path)
+                }
               update(archive)
             }
             kiwixLibrary.addBook(book)
@@ -79,6 +82,17 @@ class KiwixServer @Inject constructor(
             )
           }
         }
+        android.os.Handler(Looper.getMainLooper()).postDelayed({
+          CoroutineScope(Dispatchers.IO).launch {
+            Log.e(
+              TAG,
+              "After 5 second FD is valid = " +
+                "${zimReaderContainer.zimReaderSource?.exists()} \n" +
+                "FD can read via the dev/fd/fdNumber =" +
+                " ${zimReaderContainer.zimReaderSource?.canOpenInLibkiwix()}"
+            )
+          }
+        }, 5000)
         return@withContext KiwixServer(kiwixLibrary, Server(kiwixLibrary))
       }
   }

core/src/main/java/org/kiwix/kiwixmobile/core/webserver/ZimHostFragment.kt

@@ -230,8 +230,10 @@ class ZimHostFragment : BaseFragment(), ZimHostCallbacks, ZimHostContract.View {
   }
 
   private fun handleStoragePermissionAndServer() {
-    // we does not require any permission for playStore variant.
-    if (sharedPreferenceUtil.isPlayStoreBuildWithAndroid11OrAbove()) {
+    // we does not require any permission for playStore variant, and custom apps.
+    if (sharedPreferenceUtil.isPlayStoreBuildWithAndroid11OrAbove() ||
+      requireActivity().isCustomApp()
+    ) {
       startStopServer()
       return
     }

custom/src/main/java/org/kiwix/kiwixmobile/custom/main/CustomReaderFragment.kt

@@ -20,6 +20,7 @@ package org.kiwix.kiwixmobile.custom.main
 
 import android.app.Dialog
 import android.os.Bundle
+import android.util.Log
 import android.view.Menu
 import android.view.MenuInflater
 import android.view.View
@@ -36,7 +37,6 @@ import org.kiwix.kiwixmobile.core.R.dimen
 import org.kiwix.kiwixmobile.core.base.BaseActivity
 import org.kiwix.kiwixmobile.core.extensions.browserIntent
 import org.kiwix.kiwixmobile.core.extensions.getResizedDrawable
-import org.kiwix.kiwixmobile.core.extensions.isFileExist
 import org.kiwix.kiwixmobile.core.main.CoreReaderFragment
 import org.kiwix.kiwixmobile.core.main.MainMenu
 import org.kiwix.kiwixmobile.core.main.RestoreOrigin
@@ -44,12 +44,10 @@ import org.kiwix.kiwixmobile.core.page.history.adapter.WebViewHistoryItem
 import org.kiwix.kiwixmobile.core.reader.ZimReaderSource
 import org.kiwix.kiwixmobile.core.utils.LanguageUtils
 import org.kiwix.kiwixmobile.core.utils.dialog.DialogShower
-import org.kiwix.kiwixmobile.core.utils.files.FileUtils.getDemoFilePathForCustomApp
 import org.kiwix.kiwixmobile.core.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 import org.kiwix.kiwixmobile.custom.BuildConfig
 import org.kiwix.kiwixmobile.custom.R
 import org.kiwix.kiwixmobile.custom.customActivityComponent
-import java.io.File
 import java.util.Locale
 import javax.inject.Inject
 
@@ -220,19 +218,11 @@ class CustomReaderFragment : CoreReaderFragment() {
                 true,
                 shouldManageExternalLaunch
               )
-              // Save book in the database to display it in `ZimHostFragment`.
-              zimReaderContainer?.zimFileReader?.let { zimFileReader ->
-                // Check if the file is not null. If the file is null,
-                // it means we have created zimFileReader with a fileDescriptor,
-                // so we create a demo file to save it in the database for display on the `ZimHostFragment`.
-                val file = it.file ?: createDemoFile()
-                val bookOnDisk = BookOnDisk(zimFileReader)
-                repositoryActions?.saveBook(bookOnDisk)
-              }
               if (shouldManageExternalLaunch) {
                 // Open the previous loaded pages after ZIM file loads.
                 manageExternalLaunchAndRestoringViewState()
               }
+              saveBookInDatabase()
             }
 
             is ValidationState.HasBothFiles -> {
@@ -242,6 +232,7 @@ class CustomReaderFragment : CoreReaderFragment() {
                 // Open the previous loaded pages after ZIM file loads.
                 manageExternalLaunchAndRestoringViewState()
               }
+              saveBookInDatabase()
             }
 
             else -> {}
@@ -256,16 +247,19 @@ class CustomReaderFragment : CoreReaderFragment() {
     )
   }
 
-  private suspend fun createDemoFile() =
-    File(getDemoFilePathForCustomApp(requireActivity())).also {
-      if (!it.isFileExist()) it.createNewFile()
+  private fun saveBookInDatabase() {
+    // Save book in the database to display it in `ZimHostFragment`.
+    zimReaderContainer?.zimFileReader?.let { zimFileReader ->
+      Log.e("SELECTED_BOOKS", "saveBookInDatabase: Saving book to database")
+      repositoryActions?.saveBook(BookOnDisk(zimFileReader))
     }
+  }
 
   @Suppress("DEPRECATION")
   override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
     super.onCreateOptionsMenu(menu, inflater)
     menu.findItem(org.kiwix.kiwixmobile.core.R.id.menu_help)?.isVisible = false
-    menu.findItem(org.kiwix.kiwixmobile.core.R.id.menu_host_books)?.isVisible = false
+    menu.findItem(org.kiwix.kiwixmobile.core.R.id.menu_host_books)?.isVisible = true
   }
 
   private fun enforcedLanguage(): Boolean {