File Recovery & Deep Scan

An Android app that scans accessible storage for photos, videos, audio, and documents, classifies them by file signature, and copies selected files into a dedicated recovery folder. It also keeps a vault of recovered files and a history of past scans, and can securely shred files it has recovered.

Scope note: This app works on files the OS makes readable to it — its own cache/files directories and, with the user's permission, the shared media directories (DCIM, Pictures, Download). It classifies and copies those files; it does not perform raw disk/sector carving of truly deleted data. The debug build also seeds a few sample files into the app cache so a scan is never empty during testing.

Features

• Deep scan of app storage and (with permission) shared media folders
• Signature-based detection — files are typed by magic-header bytes first, falling back to extension (handles mismatched or missing extensions)
• Category scans — Photos, Videos, Audio, Documents, or a full scan
• Recovery — copy selected files into RecoveredFiles/ with automatic, collision-safe unique naming
• Secure shred — multi-pass (zero-fill + secure-random) overwrite before delete
• Vault & history — recovered files and past scans persisted with Room
• Cancellable scans with live progress

Architecture

MVVM with a single-activity Jetpack Compose UI:

UI (Compose)            ui/screens/MainDashboard.kt
   │  collects StateFlow
ViewModel               viewmodel/RecoveryViewModel.kt   (scan + recovery logic)
   │
Repository              data/RecoveryRepository.kt
   │
Room DAO / Database     data/RecoveryDao.kt, RecoveryDatabase.kt
   └─ Entities          data/RecoveryEntities.kt         (ScanHistory, RecoveredFile)

Tech stack

Area	Choice
Language	Kotlin 2.2.10
UI	Jetpack Compose (BOM 2024.09.00), Material 3
Async	Kotlin Coroutines + StateFlow
Persistence	Room 2.7.0 (KSP)
Build	Android Gradle Plugin 9.1.1, Gradle 9.5.1
Tests	JUnit4, Robolectric 4.16.1, Roborazzi 1.59.0
Min / Target / Compile SDK	24 / 36 / 36.1

Prerequisites

• JDK 17 (e.g. Eclipse Temurin)
• Android Studio (build 261 / 2025.x or newer — required for Gradle ≥ 9.3.1), or a standalone Gradle ≥ 9.3.1
• Android SDK with platform android-36 and matching build-tools

Getting started

1. Clone

   git clone https://github.com/RohitWaghire/File-Recovery-Deep-Scan.git
   cd File-Recovery-Deep-Scan

2. Open in Android Studio and let the Gradle sync finish. The project uses the committed Gradle wrapper (9.5.1), so no separate Gradle install is needed.

3. Generate a debug keystore. The debug build is signed with a keystore at the repo root (debug.keystore), which is gitignored. Create it once:

   keytool -genkeypair -v -keystore debug.keystore \
     -storepass android -keypass android \
     -alias androiddebugkey -keyalg RSA -keysize 2048 -validity 10000 \
     -dname "CN=Android Debug,O=Android,C=US"

4. Run on an emulator or device (▶ in Android Studio, or ./gradlew installDebug).

Optional: the Secrets Gradle plugin is wired to read a GEMINI_API_KEY from a .env file (see .env.example), but the current app code does not call any Gemini API, so this is not required to build or run.

Build & test

./gradlew assembleDebug        # build the debug APK
./gradlew testDebugUnitTest    # run the Robolectric unit tests

Unit tests are configured with Robolectric @Config(sdk = 34) so they run on JDK 17 (SDK 36 in Robolectric would require JDK 21).

Continuous integration

Every push and pull request to main runs .github/workflows/android.yml, which builds the debug APK and runs the unit tests on a fresh runner.

Permissions

Declared in AndroidManifest.xml:

• READ_EXTERNAL_STORAGE (≤ API 32)
• READ_MEDIA_IMAGES, READ_MEDIA_VIDEO, READ_MEDIA_AUDIO (API 33+)
• READ_MEDIA_VISUAL_USER_SELECTED (API 34+ partial photo/video access)

If permissions are denied, the app falls back to scanning only its own sandboxed storage.