Development

Tech Stack

Frontend

• React 19 — UI framework
• MUI v9 with @mui/icons-material and @emotion/react — components and icons
• Zustand — state management
• react-i18next + i18next — internationalization (8 locales)
• TypeScript
• Vite 7 — dev server and bundler

Backend

• Tauri v2 — desktop shell
• Rust (edition 2024, stable toolchain)
• tokio — async runtime (custom multi-thread runtime with 4 workers)
• serde + serde_json — config serialization
• anyhow — error handling
• log — diagnostic logging

Tauri plugins

• tauri-plugin-opener — open external URLs
• tauri-plugin-dialog — folder picker for the MKVToolNix path
• tauri-plugin-clipboard-manager — write the copied mkvextract command

External tools

• MKVToolNix — mkvmerge -J for track metadata, mkvextract for extraction

Tooling

• pnpm — package manager
• Deno — scripts under scripts/ts/ (e.g. change-version.ts)

Repository layout

src/                        React app
├── App.tsx                 Theme / language / launch-args bootstrap
├── main.tsx                Entry point
├── store.ts                Zustand store (files, queue, profiles, handlers)
├── service.ts              Wrappers around Tauri invoke calls
├── protocol.ts             Shared types mirroring Rust protocol
├── extract-utils.ts        Template parser, drive-key helper, formatters
├── components/
│   ├── Layout.tsx          Nav / main / footer grid
│   ├── Toolbar.tsx         Extract All, Clear All, Profile, Settings, About
│   ├── MainContent.tsx     Tab container (File List, Queue, Settings, About)
│   ├── FileList.tsx        Drop zone, polling, card list
│   ├── MkvFileCard.tsx     Per-file card with track table and progress row
│   ├── Queue.tsx           Per-drive queue cards
│   ├── Settings.tsx        Appearance / Profiles / MKV settings
│   ├── About.tsx           Hero + author + GitHub
│   └── Footer.tsx          Donation and copyright links
└── i18n/
    ├── index.ts            i18next init
    └── locales/            de, en-US, es, fr, ja, zh-CN, zh-HK, zh-TW

src-tauri/                  Rust crate
├── src/
│   ├── lib.rs              Command registration, setup hook, runtime setup
│   ├── main.rs             Binary entry
│   ├── constants.rs        APP_NAME
│   ├── config.rs           Persisted Config (display mode, theme, language,
│   │                       MKVToolNix path, profiles, active profile, window)
│   ├── controller.rs       Thin wrappers for commands (get_about / get_config /
│   │                       set_config / get_mkv_files)
│   ├── protocol.rs         Shared JSON types (About, MkvTrack, ExtractEntry, …)
│   ├── extract.rs          Per-drive queue, worker threads, cancel, event emit
│   └── mkvtoolnix.rs       mkvmerge/mkvextract resolution, spawn, progress parse
├── icons/                  App icons (also used in the About tab)
└── tauri.conf.json         Window defaults, bundle metadata

scripts/ts/
├── change-version.ts       Bumps version across manifests + workflow YAMLs
└── deno.json               Deno tasks

.github/workflows/
├── linux_build.yml
├── macos_build.yml
└── windows_build.yml

Commands

pnpm install         # install JS dependencies
pnpm tauri dev       # run the app in development (hot-reload frontend + Rust)
pnpm tauri build     # build installers for the current platform
pnpm dev             # run only the Vite dev server (no Tauri window)
pnpm build           # type-check and build the frontend

To bump the version across package.json, src-tauri/Cargo.toml, src-tauri/tauri.conf.json, and the three workflow files, edit both arguments at the bottom of scripts/ts/change-version.ts and run:

cd scripts/ts
deno task change-version

Configuration storage

The persisted config file is named BatchMkvExtract.json and lives at:

• Windows — %APPDATA%\BatchMkvExtract\ when installed under %LOCALAPPDATA% / %ProgramFiles% / %ProgramFiles(x86)%; next to the .exe in portable mode.
• Linux — $XDG_CONFIG_HOME/BatchMkvExtract/, else $HOME/.config/BatchMkvExtract/.
• macOS — ~/Library/Application Support/BatchMkvExtract/.

Frontend ↔ Backend protocol

All communication goes through Tauri's invoke and event system; there's no IPC codec beyond JSON.

Commands (#[tauri::command])

Command	Purpose
get_about	App version for the About tab
get_config / set_config	Load / save persisted config
get_launch_args	Paths passed on the command line
get_mkv_files	Resolve dropped paths (files or folders) to .mkv file paths
get_mkv_tracks	Run mkvmerge -J and return the track list
is_mkvextract_found	Validate the MKVToolNix path and surface auto-detected updates
enqueue_extract	Add a file to the per-drive queue
cancel_extract	Cancel a queued or running extraction
get_extract_status	Snapshot of active tasks (frontend polls every 200 ms)

Events

Event	Payload	When
extraction-finished	{ file, outcome: "Completed" | "Cancelled" | "Failed", error? }	Backend worker exits

Concurrency

The backend uses a custom tokio runtime with worker_threads(4) set in lib.rs. Each extraction runs on a dedicated std::thread::spawn'd worker, so long-running mkvextract child processes do not tie up the async worker pool. Per-drive serialization is enforced in extract.rs — see DriveState and on_worker_finished.

Template engine

extract-utils.ts::renderTemplate is a single-pass character scanner:

• {{ / }} escape to literal braces
• {placeholder} replaces with the corresponding value
• Unknown placeholders are emitted verbatim (e.g. {typo} stays {typo})

Supported placeholders: {file_name}, {track_id}, {track_number}, {language}, {codec_name}, {track_name}. {codec_name} and {track_name} are sanitized for filesystem-unsafe characters before substitution.

CI

Three GitHub Actions workflows build release bundles on push/PR:

• linux_build.yml — .deb, .rpm, .AppImage
• macos_build.yml — .dmg (x86_64 and arm64 via matrix)
• windows_build.yml — .msi, .exe (NSIS)

Each installs Node 24, pnpm 10, and the stable Rust toolchain, then runs cargo test -r followed by pnpm tauri build.