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)
	}
}

func TestNotificationPayloadRoundTrips(t *testing.T) {
	uid := uuid.New()
	in := notify.Notification(uid, notify.NotifyFriendRequest)
	if in.UserID != uid || in.Kind != notify.KindNotification || in.EventID == "" {
		t.Fatalf("intent metadata wrong: %+v", in)
	}
	ev := fb.GetRootAsNotificationEvent(in.Payload, 0)
	if got := string(ev.Kind()); got != notify.NotifyFriendRequest {
		t.Fatalf("notification sub-kind = %q, want %q", got, notify.NotifyFriendRequest)
	}
}