Bookava is a modern, browser-based audiobook player designed for simplicity and power. It runs entirely on the client-side as a Progressive Web App (PWA), meaning your files are never uploaded to a server. You can "install" it on your device for an offline, app-like experience. Just open the app, drop your audiobooks, and enjoy seamless listening with robust features and automatic progress saving.

• Progressive Web App (PWA): Install Bookava on your desktop or mobile device for a native-app feel. It works offline, making it the perfect companion for listening on the go.
• Serverless & Private: Runs 100% in your browser. Your files are processed locally and never uploaded, ensuring complete privacy.
• Drag & Drop Simplicity: Easily start a session by dragging and dropping your audio files, a single .zip archive, or an .m4b file.
• Comprehensive Format Support:
  • Plays standard audio formats: .mp3, .wav, .ogg, .m4a, and .flac.
  • Dedicated .m4b Audiobook Support: Automatically parses and displays chapter markers from .m4b files for easy navigation.
• Automatic Progress Saving: The player automatically saves your progress (current track, time, volume, and playback speed) in your browser's localStorage.
• Smart Session Resume: When you reopen a book, Bookava prompts you to continue exactly where you left off, restoring all your settings.
• Bookshelf History: Your recent audiobooks are saved to a beautiful, interactive bookshelf for quick access to your library.
• Advanced Playback Controls:
  • Variable playback speed from 0.5x to 16.0x.
  • Auto-Acceleration: Optionally increases speed by 0.1x every 10 minutes.
  • Quick seek buttons (-15s / +15s).
  • Full playlist view with chapter navigation.
• Keyboard Shortcuts: Control playback without your mouse:
  • Spacebar: Play/Pause
  • ArrowRight: Seek forward
  • ArrowLeft: Seek backward
• Light & Dark Themes: Switch between a sleek dark mode and a clean light mode to suit your preference.
• Metadata & Artwork Extraction: Automatically reads metadata (title, album) and cover art from your files to provide a rich user experience.
• Fully Responsive Design: A clean, minimalist UI that looks and works great on both desktop and mobile devices.
• No Installation Needed: Runs instantly in any modern browser. No complex setup or build process required.

Getting started with Bookava is incredibly simple.

1. Open the Player Since it's a PWA, you can host the files on a simple web server (like GitHub Pages) or run them locally. When you first visit the URL in a modern browser, you'll be prompted to "Install" or "Add to Home Screen". This will add Bookava to your device just like a native app.

2. Load Your Audiobook You have two options:

• Drag & Drop: Drag your audio files (e.g., chapter1.mp3), a .zip file, or a single .m4b file onto the upload zone.
• Click to Select: Click the "Choose Audiobook" button to open a file selection dialog.

3. Enjoy Listening The player will process your files, build a playlist, and start playing. Your progress is saved automatically, so you can close the app and resume later by re-loading the same audiobook.

This project is built with a focus on simplicity and performance, using pure web technologies without any frameworks.

• Core Technology: HTML5, CSS3 (with CSS Variables for theming), and Vanilla JavaScript (ES6+).
• PWA Functionality:
  • Service Worker (sw.js): Manages caching of app assets for a true offline-first experience.
  • Web App Manifest (manifest.json): Defines the app's metadata, icons, and display properties for installation.
• Client-Side Libraries:
  • zip.js: Handles the client-side unzipping of .zip archives.
  • music-metadata: Reads ID3 tags (metadata and cover art) from audio files.
  • CryptoJS: Used to generate a unique hash from file details to serve as a reliable ID for each audiobook, enabling robust history and state management.

• State Management: The player's state is managed via localStorage. A unique ID is generated for each audiobook based on a hash of its file details, allowing the state to be reliably associated with the correct book.
• PWA Lifecycle: The service worker (sw.js) ensures that the application shell is cached on install, allowing the app to load instantly and run even without an internet connection.
• M4B Chapter Parsing: The application includes logic to parse the chap atom within an .m4b file container, extracting chapter start times and titles to dynamically build the playlist.
• Client-Side File Handling: The application leverages the browser's File API and URL.createObjectURL() to handle files locally. This is memory-efficient and fast, as it avoids reading entire files into memory.
• Dynamic UI: The entire user interface is handled with pure JavaScript DOM manipulation for a lightweight and responsive experience.

This project is licensed under the MIT License.