# ObsidianDragon — Architecture Guide

A native C++17 desktop wallet for DragonX (DRGX), built with ImGui + SDL3.

## Directory Layout

```
src/
├── main.cpp                   Entry point, SDL3/backend init, render loop
├── app.h / app.cpp            App class: init, shutdown, frame dispatch
├── app_network.cpp            RPC connection, data refresh, mining ops
├── app_security.cpp           Encryption, lock screen, PIN management
├── app_wizard.cpp             First-run setup wizard
├── config/
│   └── settings.h/.cpp        JSON settings persistence (~/.config/ObsidianDragon/)
├── daemon/
│   ├── embedded_daemon.h/.cpp  dragonxd process lifecycle
│   └── xmrig_manager.h/.cpp   xmrig-hac pool mining management
├── rpc/
│   ├── rpc_client.h/.cpp      JSON-RPC over HTTPS (libcurl)
│   ├── rpc_worker.h/.cpp      Background work queue + main-thread drain
│   ├── connection.h/.cpp      DRAGONX.conf auto-detection
│   └── types.h                Transaction, address data types
├── ui/
│   ├── sidebar.h              NavPage enum, sidebar rendering
│   ├── notifications.h/.cpp   Toast notification system
│   ├── schema/
│   │   ├── ui_schema.h/.cpp       UISchema singleton (TOML → typed lookups)
│   │   ├── skin_manager.h/.cpp    Skin enumeration, switching, import
│   │   └── color_var_resolver.h/.cpp  CSS-style color resolution
│   └── windows/               Per-tab render functions (console, settings, etc.)
├── util/
│   ├── i18n.h/.cpp            Internationalization (TR() macro, I18n singleton)
│   ├── platform.h/.cpp        Cross-platform utilities (paths, URLs)
│   └── logger.h               DEBUG_LOGF / VERBOSE_LOGF macros
├── platform/                  Windows-specific (DX11 context, backdrop effects)
├── embedded/                  Build-generated headers (embedded resources)
└── resources/                 Runtime resource loading (fonts, images)
```

## Threading Model

```
┌─────────────────────────────────────────────────────────────┐
│  Main Thread (UI)                                           │
│  • ImGui render loop (App::update())                        │
│  • drainResults() each frame → executes completed callbacks │
│  • NEVER does blocking I/O                                  │
└────────────┬────────────────────────┬───────────────────────┘
             │ post()                 │ post()
             ▼                        ▼
┌────────────────────┐  ┌────────────────────────────────┐
│  worker_ (RPCWorker)│  │  fast_worker_ (RPCWorker)      │
│  General RPC polling│  │  Console commands, hashrate    │
│  refreshData() 5s   │  │  Avoids head-of-line blocking  │
└────────────────────┘  └────────────────────────────────┘

┌────────────────────────────────────────────┐
│  Monitor Threads (per child process)       │
│  • EmbeddedDaemon: reads dragonxd stdout   │
│  • XmrigManager: reads xmrig-hac stdout    │
└────────────────────────────────────────────┘
```

### Work Submission Pattern

```cpp
worker_->post([this]() -> rpc::RPCWorker::MainCb {
    json result = rpc_->call("getinfo");   // Runs on worker thread
    return [this, result]() {
        state_.connected = true;            // Runs on main thread
    };
});
```

## RPC Architecture

**Dual-client design** avoids head-of-line blocking:

| Client | Worker | Purpose |
|--------|--------|---------|
| `rpc_` | `worker_` | Main polling: balance, transactions, sync status |
| `fast_rpc_` | `fast_worker_` | Console commands, mining stats |

Both are `RPCClient` instances wrapping libcurl for JSON-RPC over HTTPS to `dragonxd`.

**Error flow:** `RPCClient::call()` throws `std::runtime_error` →
caught in worker lambda → error string captured → `MainCb` calls
`Notifications::instance().error(msg)` on main thread.

## Connection Lifecycle

```
[Disconnected] → tryConnect() every 5s
    → auto-detect DRAGONX.conf (host, port, rpcuser, rpcpassword)
    → if no config: start embedded daemon → retry
    → post async rpc_->connect() to worker_
        → success: onConnected() → state_.connected = true
        → auth 401: try .cookie auth → retry
        → failure: onDisconnected(reason) → may restart daemon
```

## UI System

### Page Routing
`NavPage` enum defines all pages. `App::update()` dispatches via switch on
`current_page_` to render functions (e.g., `RenderBalanceTab(this)`).

### Theme System
- Layout defined in `res/themes/ui.toml`, accessed via `schema::UI()`
- Skins are TOML files in `res/themes/` defining color palettes
- `scripts/expand_themes.py` merges layout into skins at build time
- Colors support CSS-style variables resolved by `ColorVarResolver`
- Hot-reload: `UISchema::pollForChanges()` watches file mtime

### Internationalization
- All UI strings use `TR("key")` macro → `I18n` singleton lookup
- Language files: `res/lang/{locale}.json` with compiled-in fallbacks
- Supported: en, es, zh, ru, de, fr, pt, ja, ko

### Notifications
```cpp
Notifications::instance().success("Transaction sent");
Notifications::instance().error("Insufficient funds");
```
Toast-style popups, bottom-right corner, 5-second default duration.

## Build System

CMake 3.20+, C++17. FetchContent for SDL3, nlohmann/json, toml++.
Bundled: ImGui, GLAD, miniz, libsodium, qrcode.

```bash
./build.sh                   # Dev build
./build.sh --mac-release     # macOS universal .app + DMG
./build.sh --linux-release   # Linux AppImage + zip
./build.sh --win-release     # Windows cross-compile (MinGW)
```

### Platform Backends
| Platform | Renderer | Notes |
|----------|----------|-------|
| Windows | DirectX 11 | `imgui_impl_dx11`, backdrop effects |
| macOS | OpenGL 3 | Universal binary (arm64+x86_64), target 11.0+ |
| Linux | OpenGL 3 | GLAD loader |

## Key Conventions

1. **Never block the main thread** — all I/O goes through `worker_->post()`
2. **Never hardcode pixel sizes** — use `schema::UI()` lookups from `ui.toml`
3. **Always use `TR()` for strings** — no hardcoded English in UI code
4. **Use `ICON_MD_*` for icons** — Material Design icon font
5. **`std::unique_ptr` for ownership** — no raw `new`/`delete`
6. **Check the right connection state** — `state_.connected` vs `rpc_->isConnected()`