Files
scrabble-game/backend/README.md
T
Ilia Denisov cf66ed7e26
Tests · Go / test (push) Successful in 7s
Tests · Integration / integration (push) Successful in 12s
Tests · Go / test (pull_request) Successful in 6s
Tests · Integration / integration (pull_request) Successful in 11s
Tests · UI / test (pull_request) Successful in 19s
Stage 9: Telegram integration (connector side-service, Mini App, out-of-app push)
New platform/telegram connector (own container, bot token only there):
- go-telegram/bot long-poll loop: /start deep-links + Mini App launch button.
- gRPC API pkg/proto/telegram/v1 (Telegram service): ValidateInitData, Notify
  (renders a localized message + deep-link button), SendToUser/SendToGameChannel
  (admin, wired in Stage 10). Generic methods are platform-agnostic (external_id).
- Bot API base override for Telegram's test environment; Dockerfile + compose
  (VPN sidecar, no public ingress); README.

Gateway:
- initData validation relocated from the gateway into the connector; the gateway
  calls ValidateInitData over gRPC (GATEWAY_CONNECTOR_ADDR), drops the bot token,
  and deletes internal/auth.
- Out-of-app push: runPushPump routes events whose recipient has no live in-app
  stream to connector.Notify, gated by /internal/push-target + the in-app-only
  flag (race-free de-dup); HasSubscribers added to the push hub.

Backend:
- Migration 00007 accounts.notifications_in_app_only (default true) + jetgen.
- ProvisionTelegram seeds a new account's language/display name from the launch
  fields; IdentityExternalID reverse lookup; /internal/push-target handler.

UI:
- Telegram Mini App launch: detect initData, apply themeParams, authTelegram,
  route the deep-link start_param (g/i/f); /telegram/ guard redirects outside
  Telegram. Vite relative base + telegram-web-app.js. In-app-only profile toggle;
  share-to-Telegram link for a friend code. Vitest + Playwright coverage.

Wire/docs/CI: fbs Profile/UpdateProfileRequest gain notifications_in_app_only
(Go + TS); go.work uses ./platform/telegram; go-unit.yaml covers it; PLAN,
ARCHITECTURE, FUNCTIONAL (+ru), UI_DESIGN, READMEs updated.
2026-06-04 07:10:21 +02:00

181 lines
11 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
# backend
Internal-only domain service for the Scrabble platform (module `scrabble/backend`).
It owns identity/sessions, accounts, and — in later stages — the lobby, game
runtime, robot, chat, history and administration. Its only network consumers are
the `gateway` and the platform side-services; it is never exposed publicly.
As of Stage 1 the backend provides the foundation: configuration, the HTTP
listener with the `/api/v1` route-group skeleton and probes, the Postgres pool
with embedded goose migrations, OpenTelemetry wiring, an in-memory session cache,
and the durable accounts / identities / sessions data model. The session and
account REST endpoints are added with the `gateway` (Stage 6); Stage 1 ships the
store/service layer they will call.
Stage 2 adds `internal/engine`, the in-process bridge to the `scrabble-solver`
library: a versioned dictionary registry, a deterministic tile bag, and a pure
rules `Game` (legal plays, passes, exchanges, resignations and end-condition
detection) that emits dictionary-independent move records. It is a library only;
the game domain wires it into the process in Stage 3.
Stage 3 adds `internal/game`, the game domain over the engine. Active games are
event-sourced: a `games` row plus an append-only decoded move journal, with the
live `engine.Game` kept warm in a cache and rebuilt by replay on a miss. It
provides create, the play/pass/exchange/resign transitions, an unlimited
score/legality preview, the hint (per-game allowance plus a profile wallet), the
word-check tool with complaint capture, per-player game state, history and GCG
export, per-account statistics on finish, and a background turn-timeout sweeper
that auto-resigns overdue turns (honouring each player's daily away window). Like
Stages 12 it is a service/store layer; the HTTP surface lands with the
`gateway` (Stage 6).
Stage 4 adds the lobby and social fabric. `internal/lobby` holds an in-memory
matchmaking pool (FIFO per variant, pairs two humans into an auto-match) and
friend-game invitations (invite → accept, starting a 24 player game once every
invitee accepts). `internal/social` owns the friend graph (request/accept),
per-user blocks, and per-game chat with nudges folded in as a message kind; chat
messages are length-capped, content-filtered (no links/emails/phone numbers,
including obfuscated forms) and stored with the sender's IP. `internal/account`
gains profile editing and the email confirm-code flow (a `Mailer` seam: SMTP or a
development log mailer). The engine now also handles **multi-player drop-out**: in
a 34 player game a resignation or timeout drops that seat and the rest play on
(the tile disposition is a per-game setting), the game ending when one active seat
remains. As before this is a service/store layer — chat and nudges are persisted
but their live delivery, and all REST endpoints, arrive with the `gateway`
(Stage 6); the services are exposed via `Server` accessors for those handlers.
Stage 5 adds the robot opponent (`internal/robot`). A pool of durable accounts —
each a `kind='robot'` identity, provisioned at startup with chat and friend
requests blocked — backs a human-like name pool. A background driver plays the
robot's moves through the public game API as an ordinary seated player (so only
`internal/engine` imports the solver): it decides once per game whether to play to
win (≈ 40%), targets a small score margin, and times its moves with a right-skewed
delay, a night-sleep window anchored to the opponent's timezone, and nudge
behaviour — all derived deterministically from the game seed, so it keeps no extra
state. The matchmaker now substitutes a pooled robot after a 10-second wait and
exposes `Poll` so a waiting player can collect the started game (the live
match-found notification arrives with the `gateway`).
Stage 6 opens the backend to the edge. The route groups gain their first
handlers (`internal/server/handlers_*.go`): gateway-only session endpoints under
`/api/v1/internal` (Telegram/guest/email login → mint, resolve, revoke) and a
slice of authenticated `/api/v1/user` operations (profile, submit play, game
state, lobby enqueue/poll, chat). Stage 8 fills in the social/account/history
operations under `/api/v1/user`: `friends/*` (request/respond/cancel/unfriend,
list/incoming, the one-time `code` issue/redeem), `blocks/*`, `invitations/*`
(create/accept/decline/cancel/list), `PUT profile`, `email/{request,confirm}`,
`stats`, and `games/:id/gcg` (finished-only). A new `internal/notify` hub feeds a
second listener — `internal/pushgrpc`, a gRPC server (`BACKEND_GRPC_ADDR`) streaming
live events (your-turn, opponent-moved, chat, nudge, match-found, notify) to the
gateway. Stage 9 adds the gateway-only `POST /api/v1/internal/push-target` (a user's
Telegram `external_id`, language and `notifications_in_app_only` flag) that the gateway
uses to route out-of-app push to the Telegram connector, extends the Telegram login to
seed a new account's language and display name from the launch fields, and adds
migration `00007` (`accounts.notifications_in_app_only`, default true).
Migration `00005` adds `accounts.is_guest`: an ephemeral guest is a durable row
with no identity, excluded from statistics. The shared wire contracts live in the
sibling [`../pkg`](../pkg) module.
## Package layout
```
cmd/backend/ # entrypoint: telemetry -> db+migrate -> registry -> cache -> game+sweeper -> robot pool+driver -> lobby+social -> server
cmd/jetgen/ # dev tool: regenerate go-jet code from a throwaway container
internal/config/ # env configuration (composes postgres + telemetry + game config)
internal/telemetry/ # OpenTelemetry providers + per-request timing middleware
internal/postgres/ # pgx-over-database/sql pool (otelsql), goose migrations
migrations/ # embedded *.sql (goose), schema `backend`
jet/ # generated go-jet models + table builders (committed)
internal/account/ # durable accounts + platform/email identities (store)
internal/session/ # opaque tokens, sessions store, write-through cache, service
internal/server/ # gin engine, route groups, X-User-ID middleware, probes
internal/engine/ # in-process scrabble-solver bridge: registry, bag, Game, replay
internal/game/ # game domain: lifecycle, journal+cache, hint, word-check, GCG, sweeper
internal/social/ # friend graph, per-user blocks, per-game chat + nudge, content filter
internal/lobby/ # in-memory matchmaking pool (+ robot substitution) + friend-game invitations
internal/robot/ # human-like robot opponent: account pool, seed-derived strategy, move driver
```
## Configuration (environment)
| Variable | Default | Notes |
| --- | --- | --- |
| `BACKEND_HTTP_ADDR` | `:8080` | HTTP (REST) listen address. |
| `BACKEND_GRPC_ADDR` | `:9090` | gRPC listen address for the live-event push stream to the gateway. |
| `BACKEND_LOG_LEVEL` | `info` | `debug` / `info` / `warn` / `error`. |
| `BACKEND_POSTGRES_DSN` | — | **Required.** pgx/libpq URL; must pin `search_path=backend`. |
| `BACKEND_POSTGRES_MAX_OPEN_CONNS` | `25` | Pool max open connections. |
| `BACKEND_POSTGRES_MAX_IDLE_CONNS` | `5` | Pool max idle connections. |
| `BACKEND_POSTGRES_CONN_MAX_LIFETIME` | `30m` | Max connection lifetime. |
| `BACKEND_POSTGRES_OPERATION_TIMEOUT` | `5s` | Connect attempt + `/readyz` ping bound. |
| `BACKEND_SERVICE_NAME` | `scrabble-backend` | OpenTelemetry `service.name`. |
| `BACKEND_OTEL_TRACES_EXPORTER` | `none` | `none` or `stdout` (OTLP arrives later). |
| `BACKEND_OTEL_METRICS_EXPORTER` | `none` | `none` or `stdout`. |
| `BACKEND_DICT_DIR` | — | **Required.** Directory of committed `.dawg` dictionaries. |
| `BACKEND_DICT_VERSION` | `v1` | Dictionary version new games pin. |
| `BACKEND_GAME_TIMEOUT_SWEEP_INTERVAL` | `1m` | How often the turn-timeout sweeper runs. |
| `BACKEND_GAME_CACHE_TTL` | `24h` | Idle window before a live game is evicted from cache. |
| `BACKEND_LOBBY_ROBOT_WAIT` | `10s` | Auto-match wait before a robot is substituted for a missing human. |
| `BACKEND_LOBBY_REAPER_INTERVAL` | `1s` | How often the substitution reaper scans for over-waited players. |
| `BACKEND_ROBOT_DRIVE_INTERVAL` | `30s` | How often the robot driver scans for due robot turns. |
| `BACKEND_SMTP_HOST` | — | Email relay host. **Empty selects the development log mailer** (the confirm-code is logged, not sent). |
| `BACKEND_SMTP_PORT` | `587` | Email relay port. |
| `BACKEND_SMTP_USERNAME` | — | SMTP user; empty relays without authentication. |
| `BACKEND_SMTP_PASSWORD` | — | SMTP password. |
| `BACKEND_SMTP_FROM` | `no-reply@localhost` | Envelope/From address for confirm-codes. |
## Run
```sh
docker run -d --name scrabble-pg -e POSTGRES_PASSWORD=dev -p 5432:5432 postgres:17-alpine
BACKEND_POSTGRES_DSN='postgres://postgres:dev@localhost:5432/postgres?search_path=backend&sslmode=disable' \
BACKEND_DICT_DIR=../../scrabble-solver/dawg \
go run ./cmd/backend
```
On boot the backend opens the pool, creates the `backend` schema if needed,
applies the embedded migrations, loads the dictionaries into the engine registry
(a hard dependency — a missing dictionary aborts the boot), warms the session
cache and starts the game turn-timeout sweeper. `GET /healthz` reports liveness;
`GET /readyz` reports 200 only when the database answers and the session cache is
warmed.
## Migrations & generated code
Migrations are plain goose SQL under `internal/postgres/migrations` (sequential
`NNNNN_name.sql`), embedded and applied at startup. After changing the schema,
regenerate the committed go-jet code (needs Docker):
```sh
go run ./cmd/jetgen # rewrites internal/postgres/jet against a temp container
```
## Engine & dictionaries
`internal/engine` consumes the sibling `scrabble-solver` module in-process. Its
bare module path (`scrabble-solver`, not a URL) cannot be fetched via VCS, so the
workspace `go.work` carries `replace scrabble-solver => ../scrabble-solver` and
the build must run from the repository root (the workspace), not from this module
in isolation. `github.com/iliadenisov/dafsa` (the DAWG loader) is a direct
dependency. CI clones the public solver repository into `../scrabble-solver`
before building (see `.gitea/workflows/`); locally, check it out next to this
repository. Committed dictionaries (`en_sowpods.dawg`, `ru_scrabble.dawg`,
`ru_erudit.dawg`) live in the solver's `dawg/` directory; the engine loads them
by `(variant, dict_version)` from a directory path. Since Stage 3 the backend
loads them at startup from the **required** `BACKEND_DICT_DIR` (a missing
dictionary aborts the boot); the future versioned-artifact direction is recorded
in [`../PLAN.md`](../PLAN.md) TODO-2.
## Tests
```sh
go test -count=1 ./... # unit tests (no Docker)
go test -tags=integration -count=1 -p=1 ./... # Postgres-backed (needs Docker)
```
Integration tests are guarded by the `integration` build tag and run against a
throwaway `postgres:17-alpine` container; they fail loudly when Docker is absent
rather than skipping. The `internal/engine` tests load the committed DAWGs from
`BACKEND_DICT_DIR` (defaulting to the sibling `../scrabble-solver/dawg`) and fail
loudly when that directory is absent.