# uo-link

> **Historical snapshot**, from before the bridge was split into
> [`RunicGateway/link`](https://gitea.whitlocktech.com/RunicGateway/link) (sidecar) and
> [`RunicGateway/servuo-plugins`](https://gitea.whitlocktech.com/RunicGateway/servuo-plugins)
> (plugin). Kept for the architecture notes below. **To set a shard up, use
> [installer/INSTALL.md](../installer/INSTALL.md)** — `deploy.ps1` as described here is a developer
> tool, not the operator path.

ServUO ⇄ Rust sidecar bridge. The shard emits newline-delimited JSON over a loopback TCP socket; the sidecar owns the WebSocket the website consumes.

```
ServUO plugin (C#, net48)  ──loopback TCP, newline-JSON──►  Rust sidecar  ──WebSocket/JSON──►  website
      (Core-thread reads)  ◄──inbound commands─────────────┘  (owns WS, auth, buffering, fan-out)
```

The shard never speaks WebSocket. Every world read happens on the Core thread; the socket is touched only by a dedicated writer thread draining a bounded queue.

## Layout

| Path | What |
|------|------|
| `overlay/` | Mirrors the ServUO server root. Everything here — and **only** this — copies over an install. |
| `patches/` | Unified diffs against stock ServUO for files we must modify rather than add. |
| `sidecar/` | The Rust sidecar: terminates the loopback link to the shard, exposes WS + REST to the website. See `sidecar/README.md`. |
| `tools/` | Never deployed. Test scaffolding and anything else that must not reach a server. |
| `INTEGRATION.md` | **Website integration guide** — the WebSocket feed, REST endpoints, auth, event catalog, and examples. Start here to build the front end. |
| `PLAN.md` | Implementation plan, measured performance budget, and the full data catalog. |
| `RESEARCH.md` | Original source-level research. Partly superseded — see the corrections table in `PLAN.md` §8. |
| `SHARD_PREREQS.md` | Repairs the target shard needed before any of this could load. |
| `deploy.ps1` | Copies `overlay/` into a server root. `-Verify` diffs instead of writing. |

Anything under `overlay/` is authoritative. Do not edit files in the server tree directly — edit here and deploy.

## Deploy

```powershell
.\deploy.ps1 -ServerPath <servuo> -Verify   # show what would change
.\deploy.ps1 -ServerPath <servuo>           # write
```

## Status

| Phase | State |
|------:|-------|
| 0 — build fix (`Scripts.csproj`) | **done, verified end-to-end** |
| 1 — transport (`BridgeLink`) | **done, acceptance in `PLAN.md` §11** |
| 2 — event streams (`BridgeEvents`) | **done, acceptance in `PLAN.md` §12** |
| 3 — sweeps (`BridgeSweeps`) | **done, acceptance in `PLAN.md` §13** |
| 4 — request/response (`BridgeRequests`) | **done, acceptance in `PLAN.md` §14** |
| 5 — `[link` account linking (`BridgeAccountLink`) | **done, acceptance in `PLAN.md` §15** |
| 6 — town-crier inbound (`BridgeTownCrier`) | **done, acceptance in `PLAN.md` §16** |
| 7 — `PlayerVendorSale` core event (`patches/` + `BridgeVendorSale`) | **done, acceptance in `PLAN.md` §17** |

Every phase on the ServUO side is complete. Phases 0–6 are drop-in (`overlay/`); Phase 7 is the one core change, shipped as `patches/`. Remaining work is the Rust sidecar.

Cheat-detection signals are not a separate phase — they are folded into the streams above: `cheat.fastwalk`, `audit.set`, `audit.command`, and `vendor.sale` (buyer + owner for laundering detection).

## Phase 0 — what it fixes

`ScriptCompiler.Compile()` runs `dotnet build Scripts/Scripts.csproj -c Release`, prints the output, and **never checks the exit code**, then `Assembly.LoadFrom("Scripts.dll")` and returns `true`. Because that build passed no `Platform`, MSBuild defaulted to `AnyCPU`, and `Scripts.csproj` gated both `OutputPath` and `DefineConstants` on `Configuration|Platform == Release|x64`. So:

- the DLL landed in `Scripts/bin/Release/` while the core loads `Scripts.dll` from the base directory, and
- `TRACE;NEWTIMERS;ServUO` went undefined, so XmlSpawner compiled its non-ServUO branches.

Runtime script compilation therefore had no effect, silently. `overlay/Scripts/Scripts.csproj` conditions both property groups on `Configuration` alone.

`Server.csproj` is deliberately left alone: nothing under `Server/` uses those symbols, and giving it `OutputPath=..\` would make the boot-time build try to overwrite the running `ServUO.exe`.

## The plugin (Phase 1)

`overlay/Scripts/Custom/Bridge/`:

| File | Responsibility |
|------|----------------|
| `BridgeConfig.cs` | Reads `Config/Bridge.cfg` in `Configure()`, before `World.Load`. |
| `BridgeJson.cs` | Outbound JSON by hand (Core thread, so no reflection serializer). Inbound via `JavaScriptSerializer`. |
| `BridgeLink.cs` | The socket. Link thread owns it; a bounded drop-oldest queue fronts it; a reader thread marshals inbound lines to the Core thread. |
| `BridgeBoot.cs` | Lifecycle, inbound dispatch, `[bridge status\|reload\|ping]`. |
| `BridgeEvents.cs` | EventSink subscriptions (Phase 2). Read-only, player-filtered, never emits secrets. |
| `BridgeSweeps.cs` | Polled streams (Phase 3): vitals, house decay on transition, economy supply. Core-thread timers. |
| `BridgeProfile.cs` | Read-model builders (Phase 4): full character profile, account roster. Core-thread reads. |
| `BridgeRequests.cs` | Inbound request handlers (Phase 4): `char.request`, `account.roster`, `vendor.snapshot`, with `bridge.error` replies. |
| `BridgeAccountLink.cs` | `[link` account linking (Phase 5): one-time code, `link.confirm`, `WebsiteUserId` account tag. |
| `BridgeTownCrier.cs` | Town-crier news (Phase 6): inbound `towncrier.add` / `remove` into the global crier list, with abuse caps. |

`Emit()` is called from the Core thread. It enqueues and returns — it never touches the socket, never blocks, never allocates a syscall. **A wedged or absent sidecar cannot stall the shard**, and that is the property everything else depends on.

## Testing

`tools/stub_sidecar.ps1` is a loopback listener that logs every line the shard sends. Run it, boot the shard, watch `server.hello` arrive. It survives a just-killed instance (SO_REUSEADDR) and won't die on a transient error.

```powershell
.\tools\stub_sidecar.ps1 -Port 7788 -Log .\sidecar.log
```

`tools/stub_sidecar_request.ps1` additionally *sends* inbound requests (`char.request`, `account.roster`, `vendor.snapshot`, plus an error case) right after the shard connects, and logs the replies — the harness used to validate Phase 4.

Note: the throwaway PowerShell sidecars are fragile — they get reaped and contend on their log file. The real Rust sidecar replaces them; don't read their flakiness as a shard problem. The shard buffers non-perishable events through any outage and reconnects on its own (observed reconnecting 5× unattended in one session).

`tools/scaffolding/` holds the world seeder and the performance probe. Neither is deployed — `deploy.ps1` only copies `overlay/`. They produced the budget in `PLAN.md` §1. See `tools/scaffolding/README.md`.
