# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Purpose

**Segnapunti Anto** is a real-time volleyball scoreboard PWA. An Express/WebSocket server hosts the game state; two separate web interfaces — a **display** (public scoreboard) and a **controller** (operator panel) — stay in sync via WebSocket.

## Commands

```bash
npm run dev          # Vite dev server — display: :5173/display, controller: :5173/controller
npm run serve        # Build + run production — display: :3000/display, controller: :3000/controller

npm run test         # Vitest watch mode
npm run test:all     # All Vitest suites once (unit, integration, component, stress)
npm run test:unit    # Unit + integration only
npm run test:component  # Vue component tests
npm run test:stress  # Load tests (50+ concurrent clients)
npm run test:e2e     # Playwright E2E (requires servers to be running via npm run serve)
npm run test:e2e:ui  # Playwright with interactive UI
```

## Architecture

```
Controller (Vue)  ──WebSocket──┐
Display (Vue)     ──WebSocket──┤── websocket-handler.js ── gameState.js
                               │         │
                               │         └── persist.js ── .segnapunti/state.json
```

All game logic lives in `src/gameState.js` as three pure functions:
- `createInitialState()` — returns the initial state
- `applyAction(state, action)` — immutable reducer (deep-clones via `structuredClone`)
- `checkVittoria(state)` — volleyball win conditions (25-point sets with 2-point margin, 15-point final set)

`src/websocket-handler.js` receives actions, validates that the sender is a registered controller (not just a display), calls `applyAction`, broadcasts the new state to all clients, then calls `onStateChange` to persist state to disk.

`server.js` (Express) serves both interfaces on port 3000: `/display` → `dist/index.html`, `/controller` → `dist/controller.html`. Single WebSocket endpoint at `/ws`.

In development, `vite-plugin-websocket.js` embeds the WebSocket server inside the Vite dev server with URL rewrite middleware for `/display` and `/controller`.

## Key Design Constraints

- **All game rules on the server** — clients are pure UI; the server is the source of truth.
- **Role-based WebSocket** — clients register as `display` or `controller`; only controllers may send actions.
- **Immutable state** — `applyAction` never mutates; always returns a new state object.
- **Single-controller intent** — the design targets one active controller and one display; no conflict resolution exists for simultaneous controllers.
- **Persistent state** — `src/persist.js` saves state to `.segnapunti/state.json` after every action and loads it on server startup.

## Test Layout

| Suite | Path | Runner |
|-------|------|--------|
| Unit | `tests/unit/` | Vitest + Node |
| Integration | `tests/integration/` | Vitest + Node |
| Component | `tests/component/` | Vitest + Happy-DOM |
| Stress | `tests/stress/` | Vitest + Node |
| E2E | `tests/e2e/` | Playwright (Chromium, Firefox, Mobile Chrome) |

E2E tests run serially (`workers: 1`) to avoid WebSocket state races. Run `npm run serve` before `npm run test:e2e`.