wip: android support

modules/background-downloader/README.md

@@ -1,6 +1,6 @@
 # Background Downloader Module
 
-A native iOS module for downloading large files in the background using `NSURLSession` with background configuration.
+A native iOS and Android module for downloading large files in the background using `NSURLSession` (iOS) and `DownloadManager` (Android).
 
 ## Features
 
@@ -10,6 +10,7 @@ A native iOS module for downloading large files in the background using `NSURLSe
 - **Cancellation**: Cancel individual or all downloads
 - **Custom Destination**: Optionally specify custom file paths
 - **Error Handling**: Comprehensive error reporting
+- **Cross-Platform**: Works on both iOS and Android
 
 ## Usage
 
@@ -201,35 +202,57 @@ interface ActiveDownload {
 - Downloads continue when app is backgrounded or suspended
 - System may terminate downloads if app is force-quit
 
+### Android Background Downloads
+
+- Uses Android's `DownloadManager` API
+- Downloads are managed by the system and continue in the background
+- Shows download notification in the notification tray
+- Downloads continue even if the app is closed
+- Requires `INTERNET` permission (automatically added by Expo)
+
 ### Background Modes
 
-The app's `Info.plist` already includes the required background mode:
+The app's `Info.plist` already includes the required background mode for iOS:
 
 - `UIBackgroundModes`: `["audio", "fetch"]`
 
 ### File Storage
 
-By default, downloaded files are saved to the app's Documents directory. You can specify a custom path using the `destinationPath` parameter.
+**iOS:** By default, downloaded files are saved to the app's Documents directory.
+
+**Android:** By default, files are saved to the app's external files directory (accessible via `FileSystem.documentDirectory` in Expo).
+
+You can specify a custom path using the `destinationPath` parameter on both platforms.
 
 ## Building
 
-After adding this module, rebuild the iOS app:
+After adding this module, rebuild the app:
 
 ```bash
+# iOS
 npx expo prebuild -p ios
 npx expo run:ios
+
+# Android
+npx expo prebuild -p android
+npx expo run:android
 ```
 
-Or install pods manually:
+Or install manually:
 
 ```bash
+# iOS
 cd ios
 pod install
 cd ..
+
+# Android - prebuild handles everything
+npx expo prebuild -p android
 ```
 
 ## Notes
 
-- Background downloads may be cancelled if the user force-quits the app
+- Background downloads may be cancelled if the user force-quits the app (iOS)
 - The OS manages download priority and may pause downloads to save battery
-- Downloads over cellular can be disabled in the module configuration if needed
+- Android shows a system notification for ongoing downloads
+- Downloads over cellular are allowed by default on both platforms

modules/background-downloader/android/build.gradle

@@ -0,0 +1,46 @@
+plugins {
+  id 'com.android.library'
+  id 'kotlin-android'
+}
+
+group = 'expo.modules.backgrounddownloader'
+version = '1.0.0'
+
+def expoModulesCorePlugin = new File(project(":expo-modules-core").projectDir.absolutePath, "ExpoModulesCorePlugin.gradle")
+def kotlinVersion = findProperty('android.kotlinVersion') ?: '1.9.25'
+
+apply from: expoModulesCorePlugin
+
+applyKotlinExpoModulesCorePlugin()
+useDefaultAndroidSdkVersions()
+useCoreDependencies()
+useExpoPublishing()
+
+android {
+  namespace "expo.modules.backgrounddownloader"
+  
+  compileOptions {
+    sourceCompatibility JavaVersion.VERSION_17
+    targetCompatibility JavaVersion.VERSION_17
+  }
+  
+  kotlinOptions {
+    jvmTarget = "17"
+  }
+  
+  lintOptions {
+    abortOnError false
+  }
+}
+
+dependencies {
+  implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
+}
+
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).configureEach {
+  kotlinOptions {
+    freeCompilerArgs += ["-Xshow-kotlin-compiler-errors"]
+    jvmTarget = "17"
+  }
+}
+

modules/background-downloader/android/build/generated/source/buildConfig/debug/expo/modules/backgrounddownloader/BuildConfig.java

@@ -0,0 +1,10 @@
+/**
+ * Automatically generated file. DO NOT MODIFY
+ */
+package expo.modules.backgrounddownloader;
+
+public final class BuildConfig {
+  public static final boolean DEBUG = Boolean.parseBoolean("true");
+  public static final String LIBRARY_PACKAGE_NAME = "expo.modules.backgrounddownloader";
+  public static final String BUILD_TYPE = "debug";
+}

modules/background-downloader/android/build/intermediates/aapt_friendly_merged_manifests/debug/processDebugManifest/aapt/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="expo.modules.backgrounddownloader" >
+
+    <uses-sdk android:minSdkVersion="24" />
+
+</manifest>

modules/background-downloader/android/build/intermediates/aapt_friendly_merged_manifests/debug/processDebugManifest/aapt/output-metadata.json

@@ -0,0 +1,18 @@
+{
+  "version": 3,
+  "artifactType": {
+    "type": "AAPT_FRIENDLY_MERGED_MANIFESTS",
+    "kind": "Directory"
+  },
+  "applicationId": "expo.modules.backgrounddownloader",
+  "variantName": "debug",
+  "elements": [
+    {
+      "type": "SINGLE",
+      "filters": [],
+      "attributes": [],
+      "outputFile": "AndroidManifest.xml"
+    }
+  ],
+  "elementType": "File"
+}

modules/background-downloader/android/build/intermediates/aar_metadata/debug/writeDebugAarMetadata/aar-metadata.properties

@@ -0,0 +1,6 @@
+aarFormatVersion=1.0
+aarMetadataVersion=1.0
+minCompileSdk=1
+minCompileSdkExtension=0
+minAndroidGradlePluginVersion=1.0.0
+coreLibraryDesugaringEnabled=false

modules/background-downloader/android/build/intermediates/annotation_processor_list/debug/javaPreCompileDebug/annotationProcessors.json

@@ -0,0 +1 @@
+{}

modules/background-downloader/android/build/intermediates/incremental/debug/packageDebugResources/compile-file-map.properties

@@ -0,0 +1 @@
+#Fri Oct 03 11:14:29 CEST 2025

modules/background-downloader/android/build/intermediates/incremental/debug/packageDebugResources/merger.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merger version="3"><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="main$Generated" generated="true" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/res"/></dataSet><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="main" generated-set="main$Generated" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/res"/></dataSet><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="debug$Generated" generated="true" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/debug/res"/></dataSet><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="debug" generated-set="debug$Generated" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/debug/res"/></dataSet><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="generated$Generated" generated="true" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/build/generated/res/resValues/debug"/></dataSet><dataSet aapt-namespace="http://schemas.android.com/apk/res-auto" config="generated" generated-set="generated$Generated" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/build/generated/res/resValues/debug"/></dataSet><mergedItems/></merger>

modules/background-downloader/android/build/intermediates/incremental/mergeDebugAssets/merger.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merger version="3"><dataSet config="main" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/assets"/></dataSet><dataSet config="debug" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/debug/assets"/></dataSet><dataSet config="generated" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/build/intermediates/shader_assets/debug/compileDebugShaders/out"/></dataSet></merger>

modules/background-downloader/android/build/intermediates/incremental/mergeDebugJniLibFolders/merger.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merger version="3"><dataSet config="main" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/jniLibs"/></dataSet><dataSet config="debug" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/debug/jniLibs"/></dataSet></merger>

modules/background-downloader/android/build/intermediates/incremental/mergeDebugShaders/merger.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merger version="3"><dataSet config="main" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/shaders"/></dataSet><dataSet config="debug" ignore_pattern="!.svn:!.git:!.ds_store:!*.scc:.*:&lt;dir>_*:!CVS:!thumbs.db:!picasa.ini:!*~"><source path="/Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/debug/shaders"/></dataSet></merger>

modules/background-downloader/android/build/intermediates/local_only_symbol_list/debug/parseDebugLocalResources/R-def.txt

@@ -0,0 +1,2 @@
+R_DEF: Internal format may change without notice
+local

modules/background-downloader/android/build/intermediates/manifest_merge_blame_file/debug/processDebugManifest/manifest-merger-blame-debug-report.txt

@@ -0,0 +1,7 @@
+1<?xml version="1.0" encoding="utf-8"?>
+2<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+3    package="expo.modules.backgrounddownloader" >
+4
+5    <uses-sdk android:minSdkVersion="24" />
+6
+7</manifest>

modules/background-downloader/android/build/intermediates/merged_manifest/debug/processDebugManifest/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="expo.modules.backgrounddownloader" >
+
+    <uses-sdk android:minSdkVersion="24" />
+
+</manifest>

modules/background-downloader/android/build/intermediates/navigation_json/debug/extractDeepLinksDebug/navigation.json

@@ -0,0 +1 @@
+[]

modules/background-downloader/android/build/intermediates/nested_resources_validation_report/debug/generateDebugResources/nestedResourcesValidationReport.txt

@@ -0,0 +1 @@
+0 Warning/Error

modules/background-downloader/android/build/intermediates/symbol_list_with_package_name/debug/generateDebugRFile/package-aware-r.txt

@@ -0,0 +1 @@
+expo.modules.backgrounddownloader

modules/background-downloader/android/build/outputs/logs/manifest-merger-debug-report.txt

@@ -0,0 +1,14 @@
+-- Merging decision tree log ---
+manifest
+ADDED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml:1:1-2:12
+INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml:1:1-2:12
+	package
+		INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml
+uses-sdk
+INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml reason: use-sdk injection requested
+INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml
+INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml
+	android:targetSdkVersion
+		INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml
+	android:minSdkVersion
+		INJECTED from /Users/fredrikburmester/Documents/GitHub/streamyfin/modules/background-downloader/android/src/main/AndroidManifest.xml

modules/background-downloader/android/src/main/AndroidManifest.xml

@@ -0,0 +1,3 @@
+<manifest>
+</manifest>
+

modules/background-downloader/android/src/main/java/expo/modules/backgrounddownloader/BackgroundDownloaderModule.kt

@@ -0,0 +1,324 @@
+package expo.modules.backgrounddownloader
+
+import android.app.DownloadManager
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.database.Cursor
+import android.net.Uri
+import android.os.Build
+import android.os.Handler
+import android.os.Looper
+import androidx.core.content.ContextCompat
+import expo.modules.kotlin.Promise
+import expo.modules.kotlin.modules.Module
+import expo.modules.kotlin.modules.ModuleDefinition
+import java.io.File
+
+class BackgroundDownloaderModule : Module() {
+  private val context
+    get() = requireNotNull(appContext.reactContext)
+
+  private val downloadManager: DownloadManager by lazy {
+    context.getSystemService(Context.DOWNLOAD_SERVICE) as DownloadManager
+  }
+
+  private val downloadTasks = mutableMapOf<Long, DownloadTaskInfo>()
+  private val progressHandler = Handler(Looper.getMainLooper())
+  private val progressRunnables = mutableMapOf<Long, Runnable>()
+
+  private val downloadCompleteReceiver = object : BroadcastReceiver() {
+    override fun onReceive(context: Context?, intent: Intent?) {
+      val downloadId = intent?.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1) ?: -1
+      if (downloadId != -1L && downloadTasks.containsKey(downloadId)) {
+        handleDownloadComplete(downloadId)
+      }
+    }
+  }
+
+  override fun definition() = ModuleDefinition {
+    Name("BackgroundDownloader")
+
+    Events(
+      "onDownloadProgress",
+      "onDownloadComplete",
+      "onDownloadError",
+      "onDownloadStarted"
+    )
+
+    OnCreate {
+      registerDownloadReceiver()
+    }
+
+    OnDestroy {
+      unregisterDownloadReceiver()
+      progressRunnables.values.forEach { progressHandler.removeCallbacks(it) }
+      progressRunnables.clear()
+    }
+
+    AsyncFunction("startDownload") { urlString: String, destinationPath: String?, promise: Promise ->
+      try {
+        val uri = Uri.parse(urlString)
+        val request = DownloadManager.Request(uri).apply {
+          setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)
+          setAllowedNetworkTypes(
+            DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE
+          )
+          setAllowedOverMetered(true)
+          setAllowedOverRoaming(true)
+
+          if (destinationPath != null) {
+            val file = File(destinationPath)
+            val directory = file.parentFile
+            if (directory != null && !directory.exists()) {
+              directory.mkdirs()
+            }
+            setDestinationUri(Uri.fromFile(file))
+          } else {
+            val fileName = uri.lastPathSegment ?: "download_${System.currentTimeMillis()}"
+            setDestinationInExternalFilesDir(
+              context,
+              null,
+              fileName
+            )
+          }
+        }
+
+        val downloadId = downloadManager.enqueue(request)
+        
+        downloadTasks[downloadId] = DownloadTaskInfo(
+          url = urlString,
+          destinationPath = destinationPath
+        )
+
+        startProgressTracking(downloadId)
+
+        sendEvent("onDownloadStarted", mapOf(
+          "taskId" to downloadId.toInt(),
+          "url" to urlString
+        ))
+
+        promise.resolve(downloadId.toInt())
+      } catch (e: Exception) {
+        promise.reject("DOWNLOAD_ERROR", "Failed to start download: ${e.message}", e)
+      }
+    }
+
+    Function("cancelDownload") { taskId: Int ->
+      val downloadId = taskId.toLong()
+      if (downloadTasks.containsKey(downloadId)) {
+        downloadManager.remove(downloadId)
+        stopProgressTracking(downloadId)
+        downloadTasks.remove(downloadId)
+      }
+    }
+
+    Function("cancelAllDownloads") {
+      val downloadIds = downloadTasks.keys.toList()
+      downloadIds.forEach { downloadId ->
+        downloadManager.remove(downloadId)
+        stopProgressTracking(downloadId)
+      }
+      downloadTasks.clear()
+    }
+
+    AsyncFunction("getActiveDownloads") { promise: Promise ->
+      try {
+        val activeDownloads = mutableListOf<Map<String, Any>>()
+        
+        downloadTasks.forEach { (downloadId, taskInfo) ->
+          val query = DownloadManager.Query().setFilterById(downloadId)
+          val cursor = downloadManager.query(query)
+          
+          if (cursor.moveToFirst()) {
+            val statusIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
+            val status = if (statusIndex >= 0) cursor.getInt(statusIndex) else -1
+            
+            activeDownloads.add(mapOf(
+              "taskId" to downloadId.toInt(),
+              "url" to taskInfo.url,
+              "state" to getStateString(status)
+            ))
+          }
+          cursor.close()
+        }
+        
+        promise.resolve(activeDownloads)
+      } catch (e: Exception) {
+        promise.reject("GET_DOWNLOADS_ERROR", "Failed to get active downloads: ${e.message}", e)
+      }
+    }
+  }
+
+  private fun registerDownloadReceiver() {
+    val filter = IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE)
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+      ContextCompat.registerReceiver(
+        context,
+        downloadCompleteReceiver,
+        filter,
+        ContextCompat.RECEIVER_NOT_EXPORTED
+      )
+    } else {
+      context.registerReceiver(downloadCompleteReceiver, filter)
+    }
+  }
+
+  private fun unregisterDownloadReceiver() {
+    try {
+      context.unregisterReceiver(downloadCompleteReceiver)
+    } catch (e: IllegalArgumentException) {
+      // Receiver not registered, ignore
+    }
+  }
+
+  private fun startProgressTracking(downloadId: Long) {
+    val runnable = object : Runnable {
+      override fun run() {
+        if (!downloadTasks.containsKey(downloadId)) {
+          return
+        }
+
+        val query = DownloadManager.Query().setFilterById(downloadId)
+        val cursor = downloadManager.query(query)
+
+        if (cursor.moveToFirst()) {
+          val statusIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
+          val status = if (statusIndex >= 0) cursor.getInt(statusIndex) else -1
+
+          val bytesDownloadedIndex = cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR)
+          val bytesDownloaded = if (bytesDownloadedIndex >= 0) cursor.getLong(bytesDownloadedIndex) else 0L
+
+          val totalBytesIndex = cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES)
+          val totalBytes = if (totalBytesIndex >= 0) cursor.getLong(totalBytesIndex) else 0L
+
+          if (status == DownloadManager.STATUS_RUNNING && totalBytes > 0) {
+            val progress = bytesDownloaded.toDouble() / totalBytes.toDouble()
+            
+            sendEvent("onDownloadProgress", mapOf(
+              "taskId" to downloadId.toInt(),
+              "bytesWritten" to bytesDownloaded,
+              "totalBytes" to totalBytes,
+              "progress" to progress
+            ))
+          }
+
+          // Check for errors
+          if (status == DownloadManager.STATUS_FAILED) {
+            val reasonIndex = cursor.getColumnIndex(DownloadManager.COLUMN_REASON)
+            val reason = if (reasonIndex >= 0) cursor.getInt(reasonIndex) else -1
+            
+            cursor.close()
+            stopProgressTracking(downloadId)
+            
+            sendEvent("onDownloadError", mapOf(
+              "taskId" to downloadId.toInt(),
+              "error" to getErrorString(reason)
+            ))
+            
+            downloadTasks.remove(downloadId)
+            return
+          }
+        }
+
+        cursor.close()
+
+        // Continue tracking if still in progress
+        if (downloadTasks.containsKey(downloadId)) {
+          progressHandler.postDelayed(this, 500)
+        }
+      }
+    }
+
+    progressRunnables[downloadId] = runnable
+    progressHandler.post(runnable)
+  }
+
+  private fun stopProgressTracking(downloadId: Long) {
+    progressRunnables[downloadId]?.let { runnable ->
+      progressHandler.removeCallbacks(runnable)
+      progressRunnables.remove(downloadId)
+    }
+  }
+
+  private fun handleDownloadComplete(downloadId: Long) {
+    stopProgressTracking(downloadId)
+
+    val taskInfo = downloadTasks[downloadId]
+    if (taskInfo == null) {
+      return
+    }
+
+    val query = DownloadManager.Query().setFilterById(downloadId)
+    val cursor = downloadManager.query(query)
+
+    if (cursor.moveToFirst()) {
+      val statusIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
+      val status = if (statusIndex >= 0) cursor.getInt(statusIndex) else -1
+
+      if (status == DownloadManager.STATUS_SUCCESSFUL) {
+        val uriIndex = cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI)
+        val localUri = if (uriIndex >= 0) cursor.getString(uriIndex) else null
+
+        if (localUri != null) {
+          val filePath = Uri.parse(localUri).path ?: localUri
+          
+          sendEvent("onDownloadComplete", mapOf(
+            "taskId" to downloadId.toInt(),
+            "filePath" to filePath,
+            "url" to taskInfo.url
+          ))
+        } else {
+          sendEvent("onDownloadError", mapOf(
+            "taskId" to downloadId.toInt(),
+            "error" to "Could not retrieve downloaded file path"
+          ))
+        }
+      } else if (status == DownloadManager.STATUS_FAILED) {
+        val reasonIndex = cursor.getColumnIndex(DownloadManager.COLUMN_REASON)
+        val reason = if (reasonIndex >= 0) cursor.getInt(reasonIndex) else -1
+        
+        sendEvent("onDownloadError", mapOf(
+          "taskId" to downloadId.toInt(),
+          "error" to getErrorString(reason)
+        ))
+      }
+    }
+
+    cursor.close()
+    downloadTasks.remove(downloadId)
+  }
+
+  private fun getStateString(status: Int): String {
+    return when (status) {
+      DownloadManager.STATUS_RUNNING -> "running"
+      DownloadManager.STATUS_PAUSED -> "suspended"
+      DownloadManager.STATUS_PENDING -> "suspended"
+      DownloadManager.STATUS_SUCCESSFUL -> "completed"
+      DownloadManager.STATUS_FAILED -> "completed"
+      else -> "unknown"
+    }
+  }
+
+  private fun getErrorString(reason: Int): String {
+    return when (reason) {
+      DownloadManager.ERROR_CANNOT_RESUME -> "Cannot resume download"
+      DownloadManager.ERROR_DEVICE_NOT_FOUND -> "No external storage device found"
+      DownloadManager.ERROR_FILE_ALREADY_EXISTS -> "File already exists"
+      DownloadManager.ERROR_FILE_ERROR -> "Storage error"
+      DownloadManager.ERROR_HTTP_DATA_ERROR -> "HTTP data error"
+      DownloadManager.ERROR_INSUFFICIENT_SPACE -> "Insufficient storage space"
+      DownloadManager.ERROR_TOO_MANY_REDIRECTS -> "Too many redirects"
+      DownloadManager.ERROR_UNHANDLED_HTTP_CODE -> "Unhandled HTTP response code"
+      DownloadManager.ERROR_UNKNOWN -> "Unknown error"
+      else -> "Download failed (code: $reason)"
+    }
+  }
+}
+
+data class DownloadTaskInfo(
+  val url: String,
+  val destinationPath: String?
+)
+

modules/background-downloader/expo-module.config.json

@@ -1,9 +1,12 @@
 {
   "name": "background-downloader",
   "version": "1.0.0",
-  "platforms": ["ios"],
+  "platforms": ["ios", "android"],
   "ios": {
     "modules": ["BackgroundDownloaderModule"],
     "appDelegateSubscribers": ["BackgroundDownloaderAppDelegate"]
+  },
+  "android": {
+    "modules": ["expo.modules.backgrounddownloader.BackgroundDownloaderModule"]
   }
 }