# ODIAN Launcher

The desktop launcher for ODIAN. It signs an operator in with their site's
Keycloak account, installs ODIAN from the site (or from an ODIAN drive),
forces an update before launch while the site is reachable, and runs ODIAN
fully offline otherwise.

| Part | Where | Stack |
|---|---|---|
| Hub UI | `src/` | Svelte 5 + Vite, bundled fonts, no network requests of its own |
| Backend | `src-tauri/` | Tauri 2 (Rust): commands and events in [docs/CONTRACT.md](docs/CONTRACT.md) |
| Installer | `crates/odian-packs/` | Rust port of the pack format v1 (`ODIAN_MCP_Server/src/odian_packs`) |

## Develop

```bash
npm install
npm run dev            # the hub in a normal browser, with a mock backend (?scenario=…)
npm run tauri dev      # the real launcher window
npm run check          # svelte-check
cargo test --workspace # Rust tests (needs ~/.cargo/bin on PATH)
```

Build the Windows setup (NSIS):

```bash
npm run tauri build
```

## How it finds the site

On first run the launcher reads `site.json` next to its executable and copies it
into its settings (`%APPDATA%\fr.odian.launcher\settings.json`). Operators can
change the addresses later in Settings. See [site.example.json](site.example.json):

```json
{ "name": "ODIAN test site", "site_url": "http://192.168.1.41:30097", "mcp_url": "http://192.168.1.41:30091" }
```

- `site_url`: the site's update service (`/v1/health`, versions, packs).
- `mcp_url`: the site's MCP, which runs the Keycloak desktop sign-in (`/auth/desktop/start`, `/auth/desktop/exchange`).

## On an operator PC

```
<install_dir>\                  D:\ODIAN when a D: drive exists, else C:\ODIAN
  versions\<v>\                 app, API, tile server and runtime files for one version
  data\db\<snapshot>\           database dumps restored into the local Postgres
  data\tiles\<style>\<dataset>\ tiles
  data\src\                     source files
  state\launcher.json           install id, installed version, last operator
  state\notes\<v>.md            patch notes, for offline reading
```

The site token lives in Windows Credential Manager under "ODIAN Launcher", one
entry per site URL. The install id is generated on the PC the first time it saves
its state, so a cloned drive never carries one.

## The local stack

`launch` starts four processes, all on 127.0.0.1, in this order, each waiting for the previous one:

| Process | Port | Working dir | Ready when |
|---|---|---|---|
| Postgres (`versions\<v>\runtime\pgsql`) | 55432 | `state\pg` | `pg_ctl start -w` returns |
| Engine API (`versions\<v>\api\odian_api.exe`) | 18080 | `state\api` | `GET /health` answers |
| Tile server (`versions\<v>\tile_server`, `runtime\python`) | 18081 | `state\tiles` | `GET /health` answers |
| ODIAN (`versions\<v>\Odian\x64\MinGW-Release\Odian.exe`) | — | `state\client` | still running after 3 s |

- Every process starts from a clean environment (Windows basics plus the ODIAN
  variables set in `src-tauri/src/stack.rs`), without a console window, inside
  one Job Object, so nothing outlives the launcher.
- Odian.exe and the API read and write relative to their working directory.
  `state\client` therefore holds junctions `assets` and `shaders` into the version
  folder, and `versions\<v>\` is never written.
- The tile server runs cache-only (`ODIAN_TILE_CACHE_ONLY=1`) from a generated
  `state\tiles\datasets.json`, and the client runs with `ODIAN_OFFLINE=1`.
- ODIAN signs in as the last operator through the local API's `/auth/mint`. The
  mint secret and the Postgres password are generated on the PC and kept in
  `state\launcher.json`.
- When Odian.exe closes, the rest stops in reverse order; Postgres stops with
  `pg_ctl stop -m fast`.