tubeFetch-Kotlin

🏗️ Technology Stack & Architecture

📱 Android App Architecture:
├── 🎯 Clean Architecture + MVVM
├── 🗃️ Room Database (for download history)
├── 🌐 Retrofit + OkHttp (for networking)
├── 💉 Hilt (Dependency Injection)
├── 🎨 Jetpack Compose (UI)
├── 🎵 MediaStore (for file storage)
├── 🔄 WorkManager (background downloads)
├── 📁 File System (actual file storage)
└── 🔐 BuildConfig (API keys management)

📁 Project Structure

Let me create the complete project structure:

1. Project Root Structure

app/
├── src/main/
│   ├── java/dev/korryr/tubefetch/
│   │   ├── data/           # Data Layer
│   │   ├── domain/         # Domain Layer  
│   │   ├── ui/            # Presentation Layer
│   │   ├── di/            # Dependency Injection
│   │   └── utils/         # Utilities
│   └── res/
├── build.gradle.kts
├── proguard-rules.pro
└── keys.properties        # API keys (gitignored)

🔐 RapidAPI YouTube Media Downloader – Developer Notes

This project uses the YouTube Media Downloader API on RapidAPI as the backend for analyzing and downloading YouTube videos.

1. Where to put secrets

• File: keys.properties (project root, gitignored)
• Required keys:
  • YOUTUBE_API_KEY=...
  • YOUTUBE_BASE_URL=https://youtube-media-downloader.p.rapidapi.com/v2/
    (keep the trailing / – Retrofit requires it)
  • YOUTUBE_HOST=youtube-media-downloader.p.rapidapi.com

These values are loaded in app/build.gradle.kts into BuildConfig:

• BuildConfig.YOUTUBE_API_KEY
• BuildConfig.YOUTUBE_BASE_URL
• BuildConfig.YOUTUBE_HOST

After editing keys.properties, always Sync Gradle.

2. How networking is wired

• Base Retrofit client & headers: app/src/main/java/dev/korryr/tubefetch/di/AppModule.kt

  • Adds on every request:
    • x-rapidapi-key: BuildConfig.YOUTUBE_API_KEY
    • x-rapidapi-host: BuildConfig.YOUTUBE_HOST
  • Uses BuildConfig.YOUTUBE_BASE_URL as .baseUrl(...).

• Retrofit interface for RapidAPI: data/remote/YouTubeWebService.kt

  • Main endpoint used:

    @GET("/v2/video/details")
    suspend fun getVideoDetails(
        @Query("videoId") videoId: String,
        @Query("urlAccess") urlAccess: String = "normal",
        @Query("videos") videos: String = "auto",
        @Query("audios") audios: String = "auto"
    ): VideoInfoResponse

• Wrapper around Retrofit + mapping: data/remote/YouTubeWebServiceImpl.kt

  • Extracts videoId from any YouTube URL (watch, youtu.be, embed).
  • Calls getVideoDetails(...).
  • Maps VideoInfoResponse → domain VideoInfo.
  • Picks the correct stream URL from videos.items / audios.items for downloads.

• Repository using the wrapper: data/repo/VideoRepositoryImpl.kt

  • analyzeVideo(url) → youTubeWebService.getVideoInfo(url).
  • downloadVideo(request) → youTubeWebService.getDownloadUrl(request.url, request.format.extension) → downloads the returned URL with OkHttp.

3. Rotating / changing the RapidAPI key

1. Get the new key from the RapidAPI dashboard.
2. Update YOUTUBE_API_KEY in keys.properties.
3. Sync Gradle and rebuild.

Nothing else in code needs to change as long as you stay on the same RapidAPI API (same host and base URL).

4. Updating endpoints or migrating API provider

• If RapidAPI changes paths (e.g. new version):

  • Update YOUTUBE_BASE_URL in keys.properties to the new base.
  • Update paths / query params in YouTubeWebService.kt to match the new docs.
  • If the JSON response shape changes, adjust VideoInfoResponse.kt and the mapping in YouTubeWebServiceImpl.toVideoInfo() / getDownloadUrl().

• If you switch away from RapidAPI entirely:

  • Replace the Retrofit interface in YouTubeWebService.kt with the new service’s endpoints.
  • Keep the domain layer contracts (VideoRepository, VideoInfo, DownloadRequest, etc.) the same to avoid touching the UI.
  • Update AppModule.provideOkHttpClient if headers or auth mechanism change.

5. Quick checklist when something breaks

If downloads or analysis stop working, verify in this order:

1. keys.properties exists locally and has non-empty values.
2. Your RapidAPI subscription is active and not rate-limited.
3. The sample curl from RapidAPI’s dashboard works with your key.
4. YOUTUBE_BASE_URL, endpoint path in YouTubeWebService.kt, and the curl URL all match.

Use Logcat’s HTTP logs (OkHttp interceptor) to see the exact URL, status code, and error message returned by RapidAPI.