Stage 6: gateway edge (Connect/FlatBuffers over h2c, platform/email/guest auth, sessions, rate-limit, admin passthrough, live push bridge)

New public ingress and the first network edge. Framework + a vertical slice of operations end-to-end; remaining ops reuse the same transcode pattern in Stage 7. Contracts (new module scrabble/pkg): - push.proto (backend->gateway gRPC server-stream) + scrabble.fbs (FlatBuffers edge payloads), committed generated Go; buf/flatc Makefiles (dev-time codegen). Backend: - REST handlers on the /api/v1 groups: internal session endpoints (telegram/guest/email login -> mint, resolve, revoke) and the user slice (profile, submit_play, state, lobby enqueue/poll, chat). - internal/notify in-process Publisher hub + internal/pushgrpc gRPC server (BACKEND_GRPC_ADDR) streaming your_turn/opponent_moved/chat/nudge/match_found; emission in game.commit, social, matchmaker. - migration 00005 accounts.is_guest; guests are durable rows excluded from stats; ProvisionGuest; email-as-login (RequestLoginCode/LoginWithCode). Gateway (new module scrabble/gateway): - Connect Gateway service over h2c (Execute + Subscribe), FlatBuffers<->JSON transcode registry, Telegram initData HMAC validator (seam), session cache, token-bucket rate limiter (3 classes), push fan-out hub, backend REST + push gRPC client, admin Basic-Auth reverse proxy. go.work: use ./pkg, ./gateway + replace scrabble/pkg. CI: gateway/**, pkg/** path filters; unit build/vet/test span all three modules. Docs (PLAN, ARCHITECTURE, FUNCTIONAL+ru, TESTING, READMEs) updated; gateway/pkg unit tests + guest/email-login integration tests.
2026-06-02 22:38:24 +02:00
parent 104eb2a978
commit 408da3f201
98 changed files with 8134 additions and 57 deletions
@@ -0,0 +1,92 @@
+package notify
+
+import (
+	"time"
+
+	flatbuffers "github.com/google/flatbuffers/go"
+	"github.com/google/uuid"
+
+	fb "scrabble/pkg/fbs/scrabblefb"
+)
+
+// The constructors below build one Intent per live event, FlatBuffers-encoding
+// the payload with the shared scrabblefb schema. Keeping the encoding here lets
+// the game/social/lobby services emit events without importing the wire schema.
+
+// YourTurn announces to userID that it is their turn in game gameID, with the
+// turn's nominal deadline.
+func YourTurn(userID, gameID uuid.UUID, deadline time.Time) Intent {
+	b := flatbuffers.NewBuilder(64)
+	gid := b.CreateString(gameID.String())
+	fb.YourTurnEventStart(b)
+	fb.YourTurnEventAddGameId(b, gid)
+	fb.YourTurnEventAddDeadlineUnix(b, deadline.Unix())
+	b.Finish(fb.YourTurnEventEnd(b))
+	return Intent{UserID: userID, Kind: KindYourTurn, Payload: b.FinishedBytes(), EventID: eventID()}
+}
+
+// OpponentMoved tells userID that seat just committed a move in game gameID,
+// summarising it (the client refetches the full state).
+func OpponentMoved(userID, gameID uuid.UUID, seat int, action string, score, total int) Intent {
+	b := flatbuffers.NewBuilder(64)
+	gid := b.CreateString(gameID.String())
+	act := b.CreateString(action)
+	fb.OpponentMovedEventStart(b)
+	fb.OpponentMovedEventAddGameId(b, gid)
+	fb.OpponentMovedEventAddSeat(b, int32(seat))
+	fb.OpponentMovedEventAddAction(b, act)
+	fb.OpponentMovedEventAddScore(b, int32(score))
+	fb.OpponentMovedEventAddTotal(b, int32(total))
+	b.Finish(fb.OpponentMovedEventEnd(b))
+	return Intent{UserID: userID, Kind: KindOpponentMoved, Payload: b.FinishedBytes(), EventID: eventID()}
+}
+
+// ChatMessage delivers a stored chat message (or nudge) to userID.
+func ChatMessage(userID, gameID, senderID uuid.UUID, id, kind, body string, createdAt time.Time) Intent {
+	b := flatbuffers.NewBuilder(128)
+	idOff := b.CreateString(id)
+	gid := b.CreateString(gameID.String())
+	sid := b.CreateString(senderID.String())
+	kindOff := b.CreateString(kind)
+	bodyOff := b.CreateString(body)
+	fb.ChatMessageStart(b)
+	fb.ChatMessageAddId(b, idOff)
+	fb.ChatMessageAddGameId(b, gid)
+	fb.ChatMessageAddSenderId(b, sid)
+	fb.ChatMessageAddKind(b, kindOff)
+	fb.ChatMessageAddBody(b, bodyOff)
+	fb.ChatMessageAddCreatedAtUnix(b, createdAt.Unix())
+	b.Finish(fb.ChatMessageEnd(b))
+	return Intent{UserID: userID, Kind: KindChatMessage, Payload: b.FinishedBytes(), EventID: eventID()}
+}
+
+// Nudge tells userID that fromUserID nudged them in game gameID.
+func Nudge(userID, gameID, fromUserID uuid.UUID) Intent {
+	b := flatbuffers.NewBuilder(64)
+	gid := b.CreateString(gameID.String())
+	from := b.CreateString(fromUserID.String())
+	fb.NudgeEventStart(b)
+	fb.NudgeEventAddGameId(b, gid)
+	fb.NudgeEventAddFromUserId(b, from)
+	b.Finish(fb.NudgeEventEnd(b))
+	return Intent{UserID: userID, Kind: KindNudge, Payload: b.FinishedBytes(), EventID: eventID()}
+}
+
+// MatchFound tells userID that game gameID, which they are seated in, has
+// started (an auto-match pairing or a robot substitution).
+func MatchFound(userID, gameID uuid.UUID) Intent {
+	b := flatbuffers.NewBuilder(64)
+	gid := b.CreateString(gameID.String())
+	fb.MatchFoundEventStart(b)
+	fb.MatchFoundEventAddGameId(b, gid)
+	b.Finish(fb.MatchFoundEventEnd(b))
+	return Intent{UserID: userID, Kind: KindMatchFound, Payload: b.FinishedBytes(), EventID: eventID()}
+}
+
+// eventID returns a best-effort correlation id for one emitted event.
+func eventID() string {
+	if id, err := uuid.NewV7(); err == nil {
+		return id.String()
+	}
+	return ""
+}
@@ -0,0 +1,110 @@
+// Package notify is the backend's in-process live-event seam. Domain services
+// publish Intents after a successful commit; the gRPC push server (internal
+// /pushgrpc) subscribes to the hub and streams them to the gateway, which fans
+// them out to clients (docs/ARCHITECTURE.md §10). Event payloads are
+// FlatBuffers-encoded by the typed constructors in events.go, so the domain
+// services stay free of the wire schema and only depend on this package.
+//
+// Publishing is best-effort and non-blocking: a live event is a convenience, not
+// a correctness requirement, so a slow or absent subscriber never blocks a game
+// transition. The default Publisher is Nop, which keeps every domain service (and
+// its tests) runnable without a live channel.
+package notify
+
+import (
+	"sync"
+
+	"github.com/google/uuid"
+)
+
+// Notification kinds — the catalog in docs/ARCHITECTURE.md §10.
+const (
+	KindYourTurn      = "your_turn"
+	KindOpponentMoved = "opponent_moved"
+	KindChatMessage   = "chat_message"
+	KindNudge         = "nudge"
+	KindMatchFound    = "match_found"
+)
+
+// Intent is one live event destined for a single user. Payload is the
+// FlatBuffers-encoded body (a scrabblefb.* table) that the gateway forwards
+// verbatim to the client; EventID is a correlation id carried through unchanged.
+type Intent struct {
+	UserID  uuid.UUID
+	Kind    string
+	Payload []byte
+	EventID string
+}
+
+// Publisher accepts live-event intents. Implementations must be safe for
+// concurrent use and must not block the caller.
+type Publisher interface {
+	Publish(intents ...Intent)
+}
+
+// Nop is the default Publisher: it discards every intent.
+type Nop struct{}
+
+// Publish discards the intents.
+func (Nop) Publish(...Intent) {}
+
+// Hub is the in-process fan-in/fan-out between the domain publishers and the
+// push subscribers (the gRPC stream). It is safe for concurrent use.
+type Hub struct {
+	mu      sync.Mutex
+	subs    map[int]chan Intent
+	nextID  int
+	bufSize int
+}
+
+// defaultBuffer is the per-subscriber queue depth used when NewHub is given a
+// non-positive size.
+const defaultBuffer = 256
+
+// NewHub returns a Hub whose per-subscriber buffer holds bufSize intents before
+// dropping (a slow subscriber never blocks a publisher).
+func NewHub(bufSize int) *Hub {
+	if bufSize <= 0 {
+		bufSize = defaultBuffer
+	}
+	return &Hub{subs: make(map[int]chan Intent), bufSize: bufSize}
+}
+
+// Publish delivers each intent to every current subscriber, dropping it for any
+// subscriber whose buffer is full (best-effort live delivery).
+func (h *Hub) Publish(intents ...Intent) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	for _, in := range intents {
+		for _, ch := range h.subs {
+			select {
+			case ch <- in:
+			default:
+			}
+		}
+	}
+}
+
+// Subscribe registers a new subscriber and returns its intent channel and an
+// unsubscribe func that closes the channel. The caller reads the channel until
+// it is closed or its own context ends, then calls unsubscribe.
+func (h *Hub) Subscribe() (<-chan Intent, func()) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	id := h.nextID
+	h.nextID++
+	ch := make(chan Intent, h.bufSize)
+	h.subs[id] = ch
+	return ch, func() { h.unsubscribe(id) }
+}
+
+// unsubscribe removes and closes the subscriber's channel. It holds the same
+// lock as Publish, so it never closes a channel mid-send.
+func (h *Hub) unsubscribe(id int) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	if ch, ok := h.subs[id]; ok {
+		delete(h.subs, id)
+		close(ch)
+	}
+}
@@ -0,0 +1,100 @@
+package notify_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/notify"
+	fb "scrabble/pkg/fbs/scrabblefb"
+)
+
+func TestHubDeliversToSubscriber(t *testing.T) {
+	h := notify.NewHub(4)
+	ch, cancel := h.Subscribe()
+	defer cancel()
+
+	want := notify.Intent{UserID: uuid.New(), Kind: notify.KindYourTurn, Payload: []byte{1, 2, 3}}
+	h.Publish(want)
+
+	select {
+	case got := <-ch:
+		if got.Kind != want.Kind || got.UserID != want.UserID {
+			t.Fatalf("delivered %+v, want %+v", got, want)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("no delivery within timeout")
+	}
+}
+
+func TestHubDropsWhenSubscriberBufferFull(t *testing.T) {
+	h := notify.NewHub(1)
+	ch, cancel := h.Subscribe()
+	defer cancel()
+
+	in := notify.Intent{UserID: uuid.New(), Kind: notify.KindNudge}
+	// Buffer holds one; the second and third are dropped, and Publish must not block.
+	h.Publish(in, in, in)
+
+	if got := len(ch); got != 1 {
+		t.Fatalf("buffered %d intents, want 1 (rest dropped)", got)
+	}
+}
+
+func TestHubUnsubscribeClosesChannel(t *testing.T) {
+	h := notify.NewHub(2)
+	ch, cancel := h.Subscribe()
+	cancel()
+
+	if _, ok := <-ch; ok {
+		t.Fatal("channel should be closed after unsubscribe")
+	}
+	// Publishing after unsubscribe must be safe (no panic, no delivery).
+	h.Publish(notify.Intent{Kind: notify.KindMatchFound})
+}
+
+func TestNopPublisherDiscards(t *testing.T) {
+	var p notify.Publisher = notify.Nop{}
+	p.Publish(notify.Intent{Kind: notify.KindYourTurn}) // must not panic
+}
+
+func TestYourTurnPayloadRoundTrips(t *testing.T) {
+	uid, gid := uuid.New(), uuid.New()
+	in := notify.YourTurn(uid, gid, time.Unix(1717000000, 0))
+	if in.UserID != uid || in.Kind != notify.KindYourTurn || in.EventID == "" {
+		t.Fatalf("intent metadata wrong: %+v", in)
+	}
+	ev := fb.GetRootAsYourTurnEvent(in.Payload, 0)
+	if got := string(ev.GameId()); got != gid.String() {
+		t.Fatalf("game id = %q, want %q", got, gid)
+	}
+	if got := ev.DeadlineUnix(); got != 1717000000 {
+		t.Fatalf("deadline = %d, want 1717000000", got)
+	}
+}
+
+func TestOpponentMovedPayloadRoundTrips(t *testing.T) {
+	uid, gid := uuid.New(), uuid.New()
+	in := notify.OpponentMoved(uid, gid, 1, "play", 24, 130)
+	if in.Kind != notify.KindOpponentMoved {
+		t.Fatalf("kind = %q", in.Kind)
+	}
+	ev := fb.GetRootAsOpponentMovedEvent(in.Payload, 0)
+	if string(ev.GameId()) != gid.String() || ev.Seat() != 1 || string(ev.Action()) != "play" || ev.Score() != 24 || ev.Total() != 130 {
+		t.Fatalf("decoded wrong: game=%q seat=%d action=%q score=%d total=%d",
+			ev.GameId(), ev.Seat(), ev.Action(), ev.Score(), ev.Total())
+	}
+}
+
+func TestChatMessagePayloadRoundTrips(t *testing.T) {
+	uid, gid, sid := uuid.New(), uuid.New(), uuid.New()
+	in := notify.ChatMessage(uid, gid, sid, "msg-1", "message", "hi", time.Unix(1717000001, 0))
+	if in.Kind != notify.KindChatMessage {
+		t.Fatalf("kind = %q", in.Kind)
+	}
+	ev := fb.GetRootAsChatMessage(in.Payload, 0)
+	if string(ev.Id()) != "msg-1" || string(ev.SenderId()) != sid.String() || string(ev.Body()) != "hi" || ev.CreatedAtUnix() != 1717000001 {
+		t.Fatalf("decoded wrong chat message: %+v", ev)
+	}
+}