lemonade/README.md

# Lemonade Stand

A browser recreation of the Atari 8-bit BASIC classic — the one you typed in,
ran on a TV, and lost two dollars to on a cloudy day.

It ships in two skins over one game. **1979** is the machine as it was: Atari
blue, block letters, scanlines, chiptune. **Remaster** is the same rules with
cel-shaded art, a crowd that turns up in proportion to trade, and a funk band.
The rules never differ between them — only the paint. Switch any time with the
button under the set.

React + TypeScript + Vite, and not one binary asset: every pixel is SVG drawn
in code and every note is generated by a small synth on the Web Audio API.

## Playing

```
npm install
npm run dev
```

It loads from cassette first, because that is how it arrived. Pressing PLAY on
the recorder is also what unlocks the audio — browsers want a gesture before
they will make a sound, and that happens to be exactly the gesture the game
already wanted.

One to four players share the keyboard, hot-seat style. Each morning you see
the weather, then decide three things: how many glasses to make, how many
15-cent signs to put up, and what to charge. Then the town votes with its
pocket money.

- Lemonade costs 2 cents a glass on days 1–2, 4 cents through day 7, and
  5 cents after that.
- Everything you make is made *today*. Unsold glasses are poured away.
- A hot, dry day brings a bigger crowd that will pay more. A heat wave is
  better still.
- A cloudy day can turn into a thunderstorm, and a thunderstorm ruins every
  glass you made.
- Street crews close the road now and then, and they tend to stay for a
  second day.
- The summer fair brings half the town past your stand, in a spending mood.
- A rival sometimes sets up on the next corner and takes a share of the
  street until they get bored and move on.
- Signs work, but with sharp diminishing returns — the fourth one barely
  earns its 15 cents.

Once the prices are in, the stand trades for a few seconds before the books
open: the crowd arrives at the rate you actually sold, the tally climbs, and
the till fills. It can be skipped, but the day is worth watching.

You are broke when you cannot afford a single glass. Otherwise the summer runs
as long as you like; **RETIRE** closes the books and shows the standings.

## High scores

One board, shared by everybody. Retiring posts every player's closing balance
to the scores service, and the top 50 comes back ranked best first — ties break
on the shorter season, then the earlier date. Runs from the summer you just
finished are picked out in yellow.

There is no way to clear it. A stand leaves the list only by being pushed off
the bottom by a better one, so a good summer stands until somebody beats it.

The board lives in `server/`, not in the browser, so it is the one part of the
game that needs a line out. With the service unreachable the game plays exactly
as normal and the board says so plainly rather than breaking; posting happens
behind the closing standings, so a slow network never holds up the end of a
season. See [server/README.md](server/README.md) for the API, the validation
and what a board with no accounts can and cannot promise.

## How it is put together

```
src/
  game/       pure simulation - no React, no DOM
    constants.ts  costs, weather profiles, the demand curve
    engine.ts     rolls each day and settles the takings
    reducer.ts    the day/turn state machine
    rng.ts        seeded mulberry32, so a run can be replayed
    highscores.ts the persisted table, with validation on load
  audio/
    synth.ts      pulse voices, a drum kit, filters, look-ahead sequencer
    tunes.ts      the 1979 chiptunes
    funk.ts       the remaster's band
  skin.ts       which of the two skins is on, and where it is kept
  components/
    PixelScene    the 1979 artwork, in chunky rectangles
    CelScene      the remaster's artwork, and the people on the street
    Scene         picks between them, so no screen needs to care
```

The simulation is deliberately kept out of React: `engine.ts` takes a player, a
decision and a day and hands back a `DayResult`. That is what makes it possible
to run a few hundred seasons in a script and check that a careful player grows
their two dollars while a reckless one goes broke about seven times in ten.

### The demand curve

The original BASIC listing is not reproduced line for line. `constants.ts`
holds a reconstruction tuned to behave the way the game plays: cheap lemonade
sells out, sales fall to nothing once the price stops being a bargain, heat
lifts both the crowd and the price people will tolerate, and signs help a lot
at first and hardly at all later.

### The television

An Atari 800 fed a 4:3 television, and a television has no scrollbar. The tube
is locked to 4:3 and everything inside it is sized in container units, so the
picture stays in proportion at any size. If a page ever did come out taller
than the tube, `Fit` scales it down rather than clipping or scrolling it.

### The people on the street

How many figures walk on is driven by trade, not decoration. Before you have
priced anything it comes from the forecast and the day's conditions — a hot day
or the fair fills the pavement, road works and a rival empty it, a downpour
leaves one soul hurrying past under an umbrella.
Once the day has traded it comes from the glasses that actually crossed the
counter, so the report shows you the crowd you earned. In a heat wave they fan
themselves.

## Sound

Audio starts on the first gesture, as browsers require. The 1979 skin gets the
chiptune: two pulse voices, a triangle bass and filtered noise, with real
Fourier-built duty cycles rather than a plain square.

The remaster gets a band. Same engine, more of it — a sine kick with a pitch
envelope, a snare with body under the crack, sixteenth hats, and a sawtooth
bass through a sweeping resonant lowpass, which is where the funk actually
lives. Patterns are written in sixteenths with a light shuffle, and chords are
just slash-separated notes in a step (`F4/A4/C5`).

Both run off one scheduler that queues notes 200 ms ahead, so the groove does
not stutter when React re-renders. `MUSIC` and `SOUND` toggle independently.

## How many people can play

As many as you like. There is no limit, and no meaningful sense in which
players share anything while they are playing.

The game holds no state on the server — it is a static bundle, and a season
lives entirely in the page. Two people, or two hundred, on any mix of
machines, browsers and profiles get completely independent games: different
seeds, different weather, different books. The server never learns a game is
happening; it only ever sees a finished score being posted at the end.

The one real cap is **four players to a game**, and that is a keyboard
limitation rather than a technical one — they are taking turns at the same
stand, hot-seat style. Nothing stops four separate people playing four
separate games at the same moment.

Everyone posts to the same leaderboard, and everyone reads the same one. That
is the only thing players have in common. The skin preference is the one thing
still kept in the browser.

## Running it anywhere

```bash
docker compose up -d --build
# game    http://localhost:8080
# scores  http://localhost:5184/api/scores
```

Two containers: a static bundle behind nginx, and the leaderboard. Only the
scores container writes anything — a named volume holding the SQLite database,
which is the one piece of state worth keeping.

The game asks for `/api`, so in production put both behind one origin and
proxy `/api/` to the scores container. Serving the game from a sub-path means
rebuilding it for that path, because asset URLs are baked in: set `BASE_PATH`
(the `web/Dockerfile` build arg) to match. Set `TRUST_PROXY=1` on the scores
container when something else terminates TLS in front of it, so the rate limit
counts players rather than counting the proxy.

## Licence

AGPL-3.0-or-later — see [LICENSE](LICENSE). Source:
<https://github.com/Coffey-Labs/lemonade>, also linked from every screen in the
game, which is what section 13 asks for.

Affero rather than plain GPL because the leaderboard is a network service:
anyone running a modified copy of it for other people has to offer them the
source. Running the game on its own imposes nothing extra.

The simulation, the artwork, the music and every word on screen are original
work — the game's *rules* are nobody's property, and nothing here is quoted
from the original. [NOTICE.md](NOTICE.md) sets out exactly what came from
where, and credits the people who wrote it first.