FastMediaSorter v2 - Technical Requirements & Stack Reference

Last Updated: April 22, 2026 Purpose: Single source of truth for the full technical stack, library inventory, platform constraints, minimum and recommended requirements.

1. Platform & SDK

Parameter	Value	Notes
Platform	Android Native	Kotlin + Java
Kotlin version	2.2.10	Pinned in `build.gradle.kts`
Java target	17	`jvmTarget = "17"`
Android Gradle Plugin	9.2.0	AGP, pinned in root `build.gradle.kts`
Gradle	9.4.1	Wrapper in `gradle/wrapper/` (AGP 9.x)
compileSdk	35	Android 15 (VanillaIceCream)
targetSdk	35	Required for Play Store compliance
minSdk (standard)	26	Android 8.0 (Oreo)
minSdk (legacy)	23	Android 6.0 (Marshmallow) - covers API 23-25
minSdk (wear)	28	Wear OS 2.0+
NDK version	27.2.12479018	For native libraries (Tesseract OCR, VR)
KSP version	2.3.2	Aligned with Kotlin 2.2.10

2. Module Structure

Module	Package Root	UI Toolkit	Purpose
`app_v2`	`com.sza.fastmediasorter`	View System + Compose	Main Android app
`wear`	`com.sza.fastmediasorter.wear`	Jetpack Compose	Wear OS companion

Product Flavors (app_v2 only)

Flavor	minSdk	Video	Audio	Images	Cloud	Documents	Animations	EPUB	Translation
`standard`	26	✅	✅	✅	✅	✅	✅	✅	✅
`lite`	26	✅	✅	✅	❌	❌	❌	❌	❌
`photos`	26	❌	❌	✅	✅	❌	✅	❌	❌
`legacy`	23	✅	✅	✅	✅	✅	✅	✅	✅

3. Architecture

Pattern: Clean Architecture + MVVM + Hilt DI
Data flow: UI → ViewModel → UseCase → Repository → DataSource
Dependency rule: UI → Domain → Data (never reverse)
Key patterns: Manager delegation, Strategy (file ops), Connection pooling (SMB)

4. Dependency Inventory

4.1 AndroidX Core

Library	Version	Purpose
`core-ktx`	1.12.0	Kotlin extensions for Android
`appcompat`	1.6.1	Backward-compatible UI framework
`constraintlayout`	2.1.4	Complex layout engine
`recyclerview`	1.3.2	Scrolling list/grid rendering
`swiperefreshlayout`	1.1.0	Pull-to-refresh gesture
`viewpager2`	1.0.0	Swipe paging
`activity-ktx`	1.8.2	Activity KTX extensions
`fragment-ktx`	1.6.2	Fragment KTX extensions
`documentfile`	1.0.1	SAF (Storage Access Framework)
`exifinterface`	1.3.7	Image metadata (EXIF)
`profileinstaller`	1.3.1	Baseline Profiles runtime
`security-crypto`	1.1.0-alpha06	EncryptedSharedPreferences

4.2 Jetpack Compose

Library	Version	Purpose
`compose-bom`	2024.02.00	BOM for Compose dependencies
`compose-ui`	(BOM)	Core Compose UI
`compose-material3`	(BOM)	Material 3 components
`compose-material-icons`	(BOM)	Icon sets (core + extended)
`activity-compose`	1.8.2	Compose Activity integration
`lifecycle-viewmodel-compose`	2.7.0	ViewModel in Compose
Compose Compiler Extension	1.5.14	Matched to Kotlin 1.9.24

4.3 Wear OS (wear module)

Library	Version	Purpose
`wear-compose-material`	1.2.1	Wear OS Material Compose
`wear-compose-foundation`	1.2.1	Wear OS Compose Foundation
`wear-compose-navigation`	1.2.1	Wear OS Compose Navigation
`play-services-wearable`	18.1.0	Phone↔Watch communication
`wear`	1.3.0	Wear OS essentials
`accompanist-permissions`	0.34.0	Runtime permission handling
`coil-compose`	2.5.0	Image loading (Compose)
`hilt-navigation-compose`	1.1.0	Hilt ViewModel in Compose Nav

Library	Version	Purpose
`lifecycle-viewmodel-ktx`	2.7.0	ViewModel with coroutines
`lifecycle-livedata-ktx`	2.7.0	LiveData with coroutines
`lifecycle-runtime-ktx`	2.7.0	Lifecycle-aware coroutines
`lifecycle-process`	2.7.0	ProcessLifecycleOwner
`navigation-fragment-ktx`	2.7.6	Fragment navigation
`navigation-ui-ktx`	2.7.6	Navigation UI integration
`navigation-safe-args`	2.7.6	Type-safe navigation args

4.5 Dependency Injection

Library	Version	Purpose
`hilt-android`	2.50	DI framework
`hilt-android-compiler`	2.50	Annotation processor (kapt/ksp)
`hilt-work`	1.1.0	Hilt + WorkManager integration
`hilt-compiler`	1.1.0	Hilt AndroidX compiler

4.6 Data Persistence

Library	Version	Purpose
`room-runtime`	2.6.1	SQLite ORM
`room-ktx`	2.6.1	Room coroutines support
`room-compiler`	2.6.1	Room annotation processor
`datastore-preferences`	1.0.0	Key-value preferences store
`paging-runtime-ktx`	3.2.1	Paging 3 library
Room DB version	19	Current schema version (see AppDatabase.kt)

4.7 Media Playback

Library	Version	Purpose
`media3-exoplayer`	1.2.1	Video/audio playback (no DASH/HLS)
`media3-ui`	1.2.1	Player UI components
`media3-common`	1.2.1	Media3 shared types
`media3-decoder`	1.2.1	Audio decoders (WAV etc.)
`media3-session`	1.2.1	MediaSession (background audio)

4.8 Image Loading & Display

Library	Version	Purpose
`glide`	4.16.0	Image loading (app_v2)
`glide-compiler`	4.16.0	Glide annotation processor
`glide-okhttp3-integration`	4.16.0	OkHttp transport for Glide
`PhotoView`	2.3.0	Pinch-to-zoom & rotation
`fastscroll`	1.3.0	Interactive RecyclerView scrollbar
`coil-compose`	2.5.0	Image loading (wear, Compose)

4.9 Network Protocols

Library	Version	Purpose
`smbj`	0.12.1	SMB 2/3 client
`jsch` (mwiede fork)	0.2.16	SFTP/SSH client
`commons-net`	3.10.0	FTP client (Apache)
`okhttp`	4.12.0	HTTP client
`retrofit`	2.9.0	REST API client
`converter-gson`	2.9.0	JSON serialization for Retrofit

4.10 Cloud Storage Providers

Library	Version	Purpose
`play-services-auth`	21.0.0	Google Sign-In (OAuth2)
`dropbox-core-sdk`	5.4.5	Dropbox API client
`msal`	6.0.1	Microsoft Identity (OneDrive)

4.11 OCR & AI

Library	Version	Purpose
`mlkit-translate`	17.0.3	On-device translation
`mlkit-text-recognition`	16.0.1	OCR (Latin/Cyrillic)
`mlkit-language-id`	17.0.6	Language identification
`tesseract4android`	4.8.0	Offline OCR (better Cyrillic)

4.12 Document Processing

Library	Version	Purpose
`epub4j-core`	4.2	EPUB parsing
`jsoup`	1.17.2	HTML parsing (EPUB content)
`markwon-core`	4.6.2	Markdown rendering
PdfRenderer	built-in	PDF rendering (API 21+)

4.13 Logging & Debugging

Library	Version	Purpose
`timber`	5.0.1	Structured logging
`leakcanary-android`	2.12	Memory leak detection (debug)
`chucker`	4.0.0	HTTP inspector (debug)
`work-multiprocess`	2.9.0	LeakCanary heap analysis (debug)

4.14 Background Processing

Library	Version	Purpose
`work-runtime-ktx`	2.9.0	WorkManager (background jobs)
`kotlinx-coroutines-android`	1.7.3	Android coroutine dispatchers
`kotlinx-coroutines-core`	1.7.3	Core coroutine library
`kotlinx-coroutines-play-services`	1.7.3	Play Services Task↔Coroutine

4.15 UI Extras

Library	Version	Purpose
`material`	1.12.0	Material Design 3 components

4.16 Build Compatibility

Library	Version	Purpose
`desugar_jdk_libs`	2.0.4	java.time.* and Java 8+ APIs on API 23-25 (legacy flavor). API 26+ uses native support.

4.17 Testing

Library	Version	Scope	Purpose
`junit`	4.13.2	unit	Test framework
`kotlinx-coroutines-test`	1.7.3	unit	Coroutine test utilities
`core-testing`	2.2.0	unit	Architecture components test
`mockk`	1.13.9	unit	Mocking framework
`robolectric`	4.11.1	unit	Android framework in JVM
`espresso-core`	3.5.1	android	UI testing
`test-ext-junit`	1.1.5	android	AndroidJUnit runner
`navigation-testing`	2.7.6	android	Navigation test utilities
`hilt-android-testing`	2.50	android	Hilt test injection
`room-testing`	2.6.1	android	Room migration tests

5. Build Configuration

Gradle Properties

Property	Value	Purpose
`org.gradle.jvmargs`	`-Xmx16g`	Max heap for Gradle daemon
`org.gradle.configuration-cache`	`true`	Faster build configuration
`org.gradle.parallel`	`true`	Parallel task execution
`org.gradle.caching`	`true`	Build cache enabled
`android.enableR8.fullMode`	`false`	R8 compat mode (faster builds)
`android.bundle.enableNativeLibraryAlignment`	`true`	16 KB page alignment (Play Store req)
`kapt.incremental.apt`	`true`	Incremental annotation processing

ProGuard / R8

Release builds: isMinifyEnabled = true, isShrinkResources = true
ProGuard rules: proguard-android.txt (non-optimizing) + proguard-rules.pro
Debug symbols: FULL level for release crash reports

Signing

Release signing configured via keystore.properties (excluded from VCS)
Debug builds use auto-generated debug keystore

Localization

Supported locales: en, ru, uk
Resource configurations restricted to these locales for APK size optimization

6. Technical Constraints & Limitations

Hard Constraints

Constraint	Details
JDK version	17 or 21 only. JDK 25+ is incompatible with the current Gradle 9.4.1 / AGP 9.2.0 toolchain
Kotlin ↔ Compose compiler match	Kotlin 1.9.24 requires Compose Compiler 1.5.14 exactly
16 KB page alignment	Mandatory for Google Play since Nov 1, 2025 (Android 15+)
`Log.d()` prohibited	Use `Timber` exclusively
Activity business logic prohibited	Delegate to Manager/Helper classes
File size limit	Max 1500ines per file; extract to `helpers/`
Room DB migration	Must increment version on any schema change
Native lib packaging	`useLegacyPackaging = false` for 16KB alignment

Logical Constraints

Constraint	Details
Cloud token storage	EncryptedSharedPreferences (per-account keys)
Token refresh	Proactive at 50 min + reactive on 401 (max 3 retries, 2s delay)
Glide memory cache	`heap × 10%` with 64 MB cap
Memory tier	Heap-aware: downgrades tier on small heap devices
FTP active mode	Fallback to active mode if passive fails
SFTP coroutine check	Must check `Job.isActive` in SSHJ callbacks
SMB connection pooling	Managed by `SmbConnectionManager`
Cloud path prefix	`cloud://` for cloud resources, `smb://`/`sftp://`/`ftp://` for network
Secret masking	Tokens/passwords auto-replaced with `***` in logs

7. Minimum Requirements (End User)

Main App (app_v2)

Parameter	Standard/Lite/Photos	Legacy flavor
Android version	8.0 (Oreo, API 26)	6.0 (Marshmallow, API 23)
RAM	≥ 2 GB	≥ 1.5 GB
Heap (dalvik.vm.heapsize)	≥ 256 MB	≥ 128 MB
Free storage	≥ 200 MB	≥ 200 MB
Google Play Services	Required for Cloud	Required for Cloud
Internet	Required for Cloud/OCR Translation	Required for Cloud/OCR Translation
Network protocols	SMB 2/3, SFTP, FTP	SMB 2/3, SFTP, FTP

Wear OS (wear)

Parameter	Value
Wear OS version	2.0+ (API 28)
RAM	≥ 1 GB
Free storage	≥ 100 MB
Companion app	Required on paired phone
Connectivity	Bluetooth/Wi-Fi to phone or direct Wi-Fi for SMB

8. Recommended Requirements (End User)

Main App (app_v2)

Parameter	Recommended
Android version	12+ (API 31+)
RAM	≥ 4 GB
Heap	≥ 512 MB
Free storage	≥ 500 MB (for OCR models + cache)
Processor	ARMv8-A (arm64-v8a) or x86_64
Screen	≥ 5” with 1080p resolution
Network	Wi-Fi 5 (802.11ac) for SMB/cloud
Google Play Services	Latest version

Wear OS (wear)

Parameter	Recommended
Wear OS version	3.0+ (API 30+)
RAM	≥ 2 GB
Display	AMOLED, 400×400+
Connectivity	Direct Wi-Fi capable

9. Build Artifacts & Commands

Quick Reference

# Debug APK (standard)
.\gradlew.bat assembleStandardDebug

# Release APK (standard)
.\gradlew.bat assembleStandardRelease

# AAB (for Google Play)
.\gradlew.bat bundleStandardRelease

# All flavors debug
.\gradlew.bat assembleDebug

# Unit tests
.\gradlew.bat testStandardDebugUnitTest

# Lint check
.\gradlew.bat lintStandardDebug

# Wear OS debug
.\gradlew.bat :wear:assembleDebug

# Build with auto-version
.\dev\build-with-version.ps1

Output Paths

Artifact	Path
Debug APK	`app_v2/build/outputs/apk/standard/debug/`
Release APK	`app_v2/build/outputs/apk/standard/release/`
AAB	`app_v2/build/outputs/bundle/standardRelease/`
Lint report (HTML)	`app_v2/build/reports/lint-results.html`
Test report (HTML)	`app_v2/build/reports/tests/testStandardDebugUnitTest/index.html`

10. Project Statistics (as of March 3, 2026)

Codebase Size

Metric	Value	Notes
Kotlin source files	541	`app_v2/` (main) + `wear/` (companion)
XML layout/config files	315	UI layouts, manifests, resources
Total lines of code	131,445	Kotlin only (src/ directory)
Total source files	856	Kotlin + XML combined

Code Objects

Object Type	Count	Notes
Classes (including data)	634	Domain models, UI, repositories, managers
Interfaces	79	Contracts for DI, repositories, use cases
Enums	41	MediaType, ResourceType, SortMode, etc.
Functions/Methods	3,098	Top-level + nested (avg ~6 per class)

Module Breakdown

Module	KT Files	LOC (approx)	Purpose
`app_v2` (main)	515	125,000	Android app (MVVM + Clean)
`wear` (companion)	26	6,445	Wear OS app (Compose)

Architectural Breakdown (app_v2)

Layer	Packages	Purpose
UI (`ui/`)	~80 files	Activities, Fragments, ViewModels, Compose
Domain (`domain/`)	~40 files	Use Cases, Models, Repository interfaces
Data (`data/`)	~150 files	Repositories, DataSources, DB, Network
Core (`core/`, `util/`, `di/`)	~80 files	DI, managers, utilities, logging
Background (`worker/`, `widget/`)	~20 files	WorkManager, widgets

Database

Aspect	Value	Notes
Room DB version	19	Latest schema with Scheduled Operations
Number of entities	15+	MediaResource, MediaFile, Cloud credentials, etc.
Migrations	17	Schema evolution from v1.0 to v2.x

11. Version History (Relevant Pinning Decisions)

Decision	Reason
Kotlin 2.2.10	Aligned with KSP 2.3.2 + Compose plugin 2.2.10
AGP 9.2.0	Requires Gradle 9.x; introduces `AndroidApiLevel`
Gradle 9.4.1	Required by AGP 9.x; JDK 17/21
Hilt 2.57.2	Current stable; via kapt (KSP migration pending)
Media3 1.2.1 (not 1.3+)	1.3+ requires API adjustments not yet validated
Glide 4.16.0	Latest stable; 5.x requires migration
SMBJ 0.12.1	Last version before breaking BC changes in 0.13
Compose BOM 2024.02.00	Matched to Wear Compose 1.2.1 compatibility

This document is the authoritative reference for technical stack and requirements. For architecture details see docs/ARCHITECTURE.md, for build/ops see docs/DEV_OPS.md.

FastMediaSorter v2 - Technical Requirements & Stack Reference

1. Platform & SDK

2. Module Structure

Product Flavors (app_v2 only)

3. Architecture

4. Dependency Inventory

4.1 AndroidX Core

4.2 Jetpack Compose

4.3 Wear OS (wear module)

4.4 Lifecycle & Navigation

4.5 Dependency Injection

4.6 Data Persistence

4.7 Media Playback

4.8 Image Loading & Display

4.9 Network Protocols

4.10 Cloud Storage Providers

4.11 OCR & AI

4.12 Document Processing

4.13 Logging & Debugging

4.14 Background Processing

4.15 UI Extras

4.16 Build Compatibility

4.17 Testing

5. Build Configuration

Gradle Properties

ProGuard / R8

Signing

Localization

6. Technical Constraints & Limitations

Hard Constraints

Logical Constraints

7. Minimum Requirements (End User)

Main App (app_v2)

Wear OS (wear)

8. Recommended Requirements (End User)

Main App (app_v2)

Wear OS (wear)

9. Build Artifacts & Commands

Quick Reference

Output Paths

10. Project Statistics (as of March 3, 2026)

Codebase Size

Code Objects

Module Breakdown

Architectural Breakdown (app_v2)

Database

11. Version History (Relevant Pinning Decisions)