transmit game actions and winner in dto

serve/dto.go

@@ -7,6 +7,10 @@ type Game struct {
 	// Players is the players in the game.
 	// The dealer is always the first player.
 	Players [2]Player `json:"players"`
+	// Action indicates the previous action taken in the game.
+	Action string `json:"action"`
+	// Winner indicates the winner of the current round, if any.
+	Winner Winner `json:"winner,omitempty"`
 	// Round is the current round.
 	Round int8 `json:"round"`
 	// Dealer indicates whether the current player is the dealer.
@@ -45,3 +49,22 @@ type GameStart struct {
 	ID     GameID `json:"id"`
 	Dealer bool   `json:"dealer"`
 }
+
+// Winner is a round winner.
+type Winner int8
+
+const (
+	NoWinner Winner = iota
+	DealerWins
+	ChallengerWins
+)
+
+var winners = [...][]byte{
+	NoWinner:       []byte("null"),
+	DealerWins:     []byte("0"),
+	ChallengerWins: []byte("1"),
+}
+
+func (w *Winner) MarshalJSON() ([]byte, error) {
+	return winners[*w], nil
+}