# Tic Tac Toe

A tic-tac-toe game with two modes: **CPU** (play against a CPU opponent that makes random moves) and **Online** (real-time 2-player over WebSocket).

## Stack
- Frontend: vanilla JS + CSS (no build step)
- Backend: Node.js + Express (serves static files) + `ws` (WebSocket) + `sql.js` (SQLite, file-based persistence)

## Project layout
```
public/            frontend (index.html, app.js, game.js, multiplayer.js, style.css)
server/            backend (server.js, db.js, package.json, pnpm-lock.yaml)
docs/              design docs
Dockerfile         production image
docker-compose.yml
```

## Run locally

The backend lives in `server/` (the frontend has no build step).

```bash
# install backend deps (pnpm)
cd server && pnpm install

# start (default port 8080)
node server/server.js
# or with an explicit port
PORT=8080 node server/server.js
```

Then open <http://localhost:8080/>.

> The server reads `PORT` (default `8080`) and optional `BASE_PATH` (default empty).

## Run with Docker

```bash
docker compose up --build
```

or build and run the image directly:

```bash
docker build -t tictactoe .
docker run -p 8080:8080 tictactoe
```

Then open <http://localhost:8080/>.

## Notes
- `server/data/` holds the SQLite file and is git-ignored.
- Online games persist to SQLite; a host who reloads can re-enter via the saved token.