ProLibertateGames/README.md

# Pilgrims of Katan

A collection of card and board games for Android, playable against the computer
or against other people over Wi-Fi (LAN).

Derived from [ProLibertateGames](https://github.com/adrianoftyriel/ProLibertateGames)
by adrianoftyriel, used under the GNU GPL v3 — see [LICENSE](LICENSE). Game
rules documentation lives under [docs/](docs/README.md); build, CI and release
decisions live in [docs/CI.md](docs/CI.md). Catan itself arrives in later work;
this app ships the reference catalogue unchanged as the regression safety net.

## What works today

The app shell is complete and every game in the catalogue is playable end to end:

| | |
| --- | --- |
| **Cards** | Euchre, Kaiser, President, Golf, Wizard, Crazy 8s, Cribbage |
| **Board** | Sequence, Chess, Checkers, Backgammon, Mastermind, Nine Men's Morris, Pirates and Bulgars, Ta Yü |

Nothing is marked *Coming soon* at the moment, because nothing is waiting. The
machinery for it is still there and still tested: a game listed in `GameCatalog`
with `available = false` appears in the menu marked *Coming soon* **on dev builds
only**, so a production release lists just what can actually be played and nobody
installs it and taps into a dead end. The menu decides this from the installed
APK's own version name — the same source the updater uses to know which channel
it is on.

Adding a game means writing a `GameRules` implementation, a `GameAi` and a
screen, then flipping `available` — the menu, lobby, networking, settings and OTA
layers are game-agnostic and need no changes.

## Playing with other people

Pick a game, choose **Host a game for others to join**, and the device advertises
itself on the network. Other devices choose **Join a game nearby** and
pick the host from the list. Seats start out filled by the computer and are
handed to people as they join, so any mix of humans and AI works — whatever is
still marked *Computer* when the host starts stays AI.

- **Wi-Fi (LAN)** — both devices must be on the same network. Discovery uses
  mDNS/NSD; play runs over a TCP socket.

### How a match is kept in step

The host is authoritative. Clients send *intents* ("I would like to play this
card") and the host re-validates every one against the rules before it takes
effect — a client cannot make an illegal move by sending a malformed message.
Each client is then sent a state **redacted for its own seat**, so opponents'
hands and the deck order are never transmitted to devices that should not see
them.

## Scorekeeper

**Scorekeeper** on the main menu is a pencil for games the app does not deal —
darts, rummy, whatever is actually on the table. It is laid out as the paper
it replaces: a column per player with their name at the head, a row per round
running down the page, and the running total ruled off at the foot.

```
     Alice   Bob   Carol
 1     +3     −1      +2
 2     +5     +7       •
 3   [   ] [   ]  [   ]   ← the row being filled in
 Σ      8      6       2
```

The bottom row is always the one being filled in. Finish it and it is written
down, and a fresh empty row opens above the totals for the next round. The
totals and that button stay put while the rounds scroll under them, so the
tally is never off-screen.

Tap a column head to name it or remove that player; **drag it sideways to move
the column**, and the whole column travels with the name. That works because
points are recorded against a player's id rather than their position, so
reordering the sheet moves the columns and nothing else. Ids are handed out
once and never reused: somebody sitting down where somebody else got up starts
at nought instead of inheriting a stranger's score. Removing a player does take
their points with them — a score nobody can see is a score nobody can correct.

Rounds are not written in ink. Tapping a round number down the left edge opens
that row for correction or lets it be struck out, and the totals follow.

Points are taken away by typing a minus, or with the **±** button, which flips
the last number typed. Not every keyboard offers a minus on its number pad, and
subtracting has to work on all of them.

### Sharing a sheet between devices

Tap **Share** and this phone becomes the host of its sheet; others choose
**Scorekeeper → Join a shared sheet nearby**. Discovery and joining by address
work exactly as they do for a game, hotspot included. Nobody is let in on their
own say-so: the host gets a prompt with the guest's name and has to **Allow** or
**Deny** it. A guest who was let in and drops out — a locked phone, say — is let
straight back in rather than asked again, and the host can **Remove** anybody
from the Sharing panel.

Everyone on the sheet can add rounds, correct them, rename and move columns. The
host's copy is the truth, and what travels is what was *done* ("add a round
with these points"), not whole sheets, so two people entering a round at once
get two rounds rather than one overwriting the other. A guest's own change shows
immediately and is laid over whatever the host sends until the host confirms it.
**Sync** asks the host for the sheet as it stands, and happens by itself when the
app comes back to the front. The host keeps the sheet as its own saved one;
a guest's view is not saved, and leaving puts them back on their own sheet. Only
the host can start a new game.

The sheet is saved as it is edited, so leaving the app or taking a phone call
does not lose the game. It is kept in its own DataStore rather than with the
settings, because it is a game in progress rather than a preference.

`score/ScoreSheet.kt` holds the whole model and, like `game/`, has no Android in
it: every rule above is a pure function and unit-tested on the JVM.

## Settings

- **Sound** on/off.
- **Animation speed**, 0.5×–2×. One multiplier drives card movement and how long
  the computer appears to think.
- **Updates** — check on launch, or check on demand. The channel is this
  project's own Gitea releases ([docs/CI.md](docs/CI.md)), and **there is no
  channel to choose**: a build updates from its own channel and no other. The
  settings screen states which one is running rather than offering a switch.
  `BuildConfig.OTA_ENABLED` is the kill switch, not a preference.

  The check on launch **only ever speaks when there is a build to install**. It
  runs behind the splash and waits for it to clear, and an app that is already
  current — or a phone that cannot reach the release server — says nothing,
  because opening the app was not a question. The button in Settings is a
  question, so it answers every time, including "you're on the latest" and
  whatever went wrong.

  Wanting both means installing both — they are separate apps and each updates
  itself, see [Both channels on one device](#both-channels-on-one-device).

## Branding

Neutral, original, and deliberately *not* Catan's: no third-party marks or
trade dress ship in this app (rebrand scope: WALA-118). The launcher icon is a
hexagonal ring around a solid core — a game tile, not any game's logo — drawn
as vector drawables so it stays sharp at every density and needs no PNGs. The
app opens on the brand field fading to its deep shade, the name set in a Celtic
uncial hand for two seconds before it fades into the menu.

A dev build wears the **dev green** field where production wears **slate
blue**, and installs as *Pilgrims of Katan DEV*. That is what tells the two
copies apart when both are on the phone; see
[Both channels on one device](#both-channels-on-one-device). The palette lives
in `ui/theme/Theme.kt` (`BrandField`, `BrandDeep`, `BrandAccent`) and the two
channel colours are generated per build by `resValue` in `app/build.gradle.kts`
— the icon vectors reference `@color/brand_field` rather than a literal, which
is how one set of vectors serves both colourways.

Two honest caveats:

- **The typeface is bundled under a licence.** Uncial Antiqua, © 2011 Brian J.
  Bonislawsky DBA Astigmatic, Reserved Font Name "Uncial Antiqua", used under
  the SIL Open Font License 1.1. The full licence is at
  [docs/licenses/UncialAntiqua-OFL.txt](docs/licenses/UncialAntiqua-OFL.txt) and
  must stay with the font — the OFL requires it to be distributed alongside.
- **The upstream's clan tartan is gone; its code is not.** The Wallace tartan
  was the upstream's brand and left with the rebrand. The GPL-licensed history
  that produced this app remains in git, and the source stays at
  [adrianoftyriel/ProLibertateGames](https://github.com/adrianoftyriel/ProLibertateGames)
  as the `upstream` remote.

## Screen sizes

There are no fixed orientations or hard-coded card sizes. Layouts measure the
space they are given: the menu grid reflows by width, the Sequence board is
always square and sized to fit whatever is left after the hand, and card widths
are a fraction of the smaller screen dimension. Rotation is handled inside the
activity, so a hand is not lost when the device turns.

The Ta Yü board is the tightest fit of the lot — 18 × 18 cells comes out under
20dp a cell on a phone — which is why laying a tile there is a tap to line the
placement up and a button to commit it, rather than a single tap on a target
smaller than a fingertip.

## Building

```sh
./gradlew assembleDebug          # APK at app/build/outputs/apk/debug/
./gradlew testDebugUnitTest      # rules engines and AI
```

Requires JDK 17 and the Android SDK (compileSdk 34).

A local build is a dev build: it installs as
`ca.wallacenet.pilgrimsofkatan.dev` under the name *Pilgrims of Katan DEV* on
the dev green field, so it goes on beside a production copy rather than over it.
Set `PLG_CHANNEL=production` to build the production package
(`ca.wallacenet.pilgrimsofkatan`, slate blue).

## CI

Full decision record: [docs/CI.md](docs/CI.md).

- `.github/workflows/ci.yml` — builds, tests and lints on `dev` and on pull
  requests into `dev` or `main`, and publishes a dev prerelease from `dev`.
- `.github/workflows/release.yml` — builds and publishes the production release
  on push to `main`, or by hand (`workflow_dispatch`).
- Both publish through [scripts/publish-release.sh](scripts/publish-release.sh)
  against Gitea's REST API, which is also runnable by hand. **No Actions runner
  is registered on the instance yet**, so until one is, the local build is the
  guaranteed path (`./gradlew assembleDebug && ./gradlew testDebugUnitTest`)
  and releases go out via the script.

### The version series

A version is **`<series>.<build number>`**. Both values are set by hand, once,
in `gradle.properties`:

```properties
plgVersionSeries=1.4
plgVersionRunOffset=1000
```

Both workflows read those same properties when they name a release tag, and the
build reads them when it stamps the APK, so the tag and what is inside it cannot
name different versions. Changing either is a one-line change to that file and
nothing else — but they are not equivalent:

- The **series** is a name for people. Bumping it changes nothing about
  ordering.
- The **build number** is what the machines compare: `versionCode`, the tag's
  trailing number, and the number in `versionName`, all the same figure —
  `CI run number + plgVersionRunOffset`. Because the offset never changes and
  the run number only climbs, going from 1.4 to 1.5 never looks like a downgrade
  to Android and never interrupts an OTA update.

The offset exists because Gitea Actions restarts run numbers at 1 for each
workflow: without a floor, the first release of a fresh instance would collide
with the `versionCode 1` every unstamped local build carries, and a counter
reset would make Android refuse the next build outright. Full reasoning in
[docs/CI.md](docs/CI.md).

### Update channels

`ci.yml` stamps builds of `dev` as dev-channel, `release.yml` stamps `main` as
production, so an APK's identity is decided where it is built. Publishing goes
to this project's Gitea releases, and the rules it keeps:

- production comes only from `main` (`release.yml` refuses any other branch);
- dev prereleases are marked so the "latest release" endpoint can never hand one
  to a production install;
- pull requests build and check but never publish.

**The two channels have independent version sequences** — a build's `versionCode`
is the build number of the workflow that produced it (run number + offset), and
the two workflows count separately, so the numbers say nothing across the
divide.

That is why **an install only ever updates within its own channel**, and why
there is no setting for it. The app reads the `-dev` suffix in its own
`versionName` to know which line it is on, asks only that channel, and refuses
anything that comes back belonging to the other one — checked again at the point
of decision rather than trusted from the fetch. The rule is a pure function,
`verdictFor` in `update/UpdatePolicy.kt`, with no Android in it, so it is
unit-tested on the JVM like the rules engines are.

### Both channels on one device

A dev build installs under its own `applicationId`,
`ca.wallacenet.pilgrimsofkatan.dev`, so it is a separate app as far as Android
is concerned and can sit beside the production copy rather than replacing it. Each channel still updates itself
normally, because an update within a channel keeps the same package.

Three things move together, all off `isDevBuild` in `app/build.gradle.kts`:

| | Production | Dev |
| --- | --- | --- |
| `applicationId` | `ca.wallacenet.pilgrimsofkatan` | `ca.wallacenet.pilgrimsofkatan.dev` |
| Launcher name | Pilgrims of Katan | Pilgrims of Katan DEV |
| Brand field | slate blue | deep green |

Anything that is not an explicit `PLG_CHANNEL=production` build is a dev build,
so a local `assembleDebug` is a dev build too and installs alongside a release
without uninstalling anything.

They have to move together. A dev package wearing the production name and
colours is precisely the mix-up that having both installed is meant to prevent,
which is why one flag drives all three rather than each being set by hand. The
name and the colours reach the resources through `resValue`, so `app_name`,
`brand_field` and `splash_background` are generated by the build and are
deliberately *not* in `res/values/` — the icon vectors reference
`@color/brand_field` rather than a literal, which is how one set of vectors
serves both colourways. `BuildConfig.DEV_BUILD` carries the same flag into
Kotlin, where `BrandField` picks the matching Compose colour for the splash.

Because they are separate apps, having both is a matter of installing both, and
each then updates itself down its own line. Nothing in the app moves a phone
from one channel to the other: the settings screen states which build is
running and where its updates come from, and that is all it does.

The debug keystore is committed on purpose: every build is signed with the same
key, so an OTA update installs over the previous one instead of being rejected
for a signature mismatch.

## Rules

The exact rules implemented, and the options that vary them, are documented per
game (index: [docs/README.md](docs/README.md)):

- [Euchre](docs/RULES-euchre.md)
- [Sequence](docs/RULES-sequence.md) — **note the caveat about the board layout**
- [Kaiser](docs/RULES-kaiser.md)
- [President](docs/RULES-president.md)
- [Golf](docs/RULES-golf.md)
- [Wizard](docs/RULES-wizard.md)
- [Crazy 8s](docs/RULES-crazy8s.md)
- [Cribbage](docs/RULES-cribbage.md) — two, three or four, and **note that four
  play in partnerships pegging on one score**
- [Chess](docs/RULES-chess.md)
- [Checkers](docs/RULES-checkers.md) — **note the caveat about flying kings**
- [Backgammon](docs/RULES-backgammon.md) — **note that there is no doubling cube**
- [Mastermind](docs/RULES-mastermind.md) — played as a duel: each player sets
  the code the other has to break
- [Nine Men's Morris](docs/RULES-morris.md)
- [Pirates and Bulgars](docs/RULES-pirates.md) — **note the caveats about the
  reconstruction**: the book the theme comes from could not be obtained, so the
  document says which rules are attested and which were chosen
- [Ta Yü](docs/RULES-tayu.md) — **note the caveats about the reconstruction**:
  the game is out of print and the rulebook could not be obtained, so the
  document says which parts are attested and which were derived

## Layout

```
game/          rules engines and AI — pure Kotlin, no Android, unit-tested
  cards/       deck, suits, ranks
  engine/      GameRules / GameAi contracts, seats, table config
  euchre/      Euchre model, rules, AI
  kaiser/      Kaiser model, bidding, rules, AI
  sequence/    Sequence model, board, rules, AI
  president/   President model, rules, AI
  golf/        Golf model, scoring, rules, AI
  wizard/      Wizard model, rules, AI
  crazyeights/ Crazy 8s model, rules, AI
  cribbage/    Cribbage the crib, the play, the show, and a counting AI
  chess/       Chess model, FEN, move generation, search
  morris/      Nine Men's Morris board geometry, mills, rules, search
  checkers/    Checkers board, compulsory captures, crowning, search
  backgammon/  Backgammon points, dice, the maximal-roll rule, turn search
  mastermind/  Mastermind codes, scoring, and a code breaker
  pirates/     Pirates and Bulgars — the cross board, the hunt, search
  tayu/        Ta Yü tile geometry, river rules, scoring, AI
net/           wire protocol, LAN transport, lobby, match driver
score/         scorekeeper sheet — pure Kotlin, unit-tested — and its store
settings/      DataStore-backed preferences
update/        OTA updater against this repo's Gitea releases, and the
              channel rule — pure, tested
ui/            Compose screens
```

Keeping `game/` free of Android types is deliberate: the same code drives the
AI, the host's authoritative state and the JVM unit tests.