transmit game actions and winner in dto

game/action.go

@@ -0,0 +1,35 @@
+package game
+
+type action uint8
+
+const (
+	actStart action = iota // start of match
+
+	actShoot          // fired, note prev indicates whether the shell was live
+	actGameEnd        // end of game but not round
+	actBeerGameEnd    // used a beer to end the game
+	actChallengerWins // challenger wins the round
+	actDealerWins     // dealer wins the match
+
+	// current player uses an item
+	actLens
+	actCig
+	actBeer // note prev indicates whether the shell was live
+	actCuff
+	actKnife
+
+	actDealerConcedes     // dealer concedes
+	actChallengerConcedes // challenger concedes
+)
+
+//go:generate go run golang.org/x/tools/cmd/stringer@v0.17.0 -type=action -trimprefix=act
+
+// gameStart returns whether the action indicates the start of a game.
+func (a action) gameStart() bool {
+	switch a {
+	case actStart, actGameEnd, actBeerGameEnd, actChallengerWins:
+		return true
+	default:
+		return false
+	}
+}

game/action_string.go

@@ -0,0 +1,35 @@
+// Code generated by "stringer -type=action -trimprefix=act"; DO NOT EDIT.
+
+package game
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[actStart-0]
+	_ = x[actShoot-1]
+	_ = x[actGameEnd-2]
+	_ = x[actBeerGameEnd-3]
+	_ = x[actChallengerWins-4]
+	_ = x[actDealerWins-5]
+	_ = x[actLens-6]
+	_ = x[actCig-7]
+	_ = x[actBeer-8]
+	_ = x[actCuff-9]
+	_ = x[actKnife-10]
+	_ = x[actDealerConcedes-11]
+	_ = x[actChallengerConcedes-12]
+}
+
+const _action_name = "StartShootGameEndBeerGameEndChallengerWinsDealerWinsLensCigBeerCuffKnifeDealerConcedesChallengerConcedes"
+
+var _action_index = [...]uint8{0, 5, 10, 17, 28, 42, 52, 56, 59, 63, 67, 72, 86, 104}
+
+func (i action) String() string {
+	if i >= action(len(_action_index)-1) {
+		return "action(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _action_name[_action_index[i]:_action_index[i+1]]
+}

game/game.go

@@ -39,6 +39,8 @@ type Match struct {
 	// prev is a pointer to the element of shellArray which was fired last this
 	// game, or nil if none has been.
 	prev *bool
+	// action is a description of the previous action.
+	action action
 
 	// shellArray is the backing storage for shells and prev.
 	shellArray [8]bool
@@ -188,18 +190,22 @@ func (g *Match) Shoot(id player.ID, self bool) error {
 		target = g.CurrentPlayer()
 	}
 	live := g.popShell()
+	g.action = actShoot
 	if live {
 		target.hp -= g.damage
 		if target.hp <= 0 {
 			target.hp = 0 // in case it goes negative
+			g.action = actChallengerWins
 			// If the target is the challenger, the match is over as well.
 			if target == &g.players[1] {
+				g.action = actDealerWins
 				g.round = 3
 			}
 			return ErrRoundEnded
 		}
 	}
 	if g.Empty() {
+		g.action = actGameEnd
 		return ErrGameEnded
 	}
 	if !self || live {
@@ -214,8 +220,10 @@ func (g *Match) Shoot(id player.ID, self bool) error {
 func (g *Match) Concede(id player.ID) error {
 	switch id {
 	case g.players[0].id:
+		g.action = actDealerConcedes
 		g.players[0].hp = 0
 	case g.players[1].id:
+		g.action = actChallengerConcedes
 		g.players[1].hp = 0
 	default:
 		return ErrWrongTurn
@@ -227,15 +235,24 @@ func (g *Match) Concede(id player.ID) error {
 // DTO returns the current match state as viewed by the given player.
 func (g *Match) DTO(id player.ID) serve.Game {
 	var live, blank int
-	if g.turn == 1 {
+	if g.action.gameStart() {
 		live = len(g.shells) / 2
 		blank = len(g.shells) - live
 	}
+	w := serve.NoWinner
+	switch g.RoundWinner() {
+	case &g.players[0]:
+		w = serve.DealerWins
+	case &g.players[1]:
+		w = serve.ChallengerWins
+	}
 	return serve.Game{
 		Players: [2]serve.Player{
 			g.players[0].DTO(),
 			g.players[1].DTO(),
 		},
+		Action:   g.action.String(),
+		Winner:   w,
 		Round:    g.round,
 		Dealer:   g.CurrentPlayer() == &g.players[0],
 		Damage:   g.damage,

game/game_test.go

@@ -446,6 +446,7 @@ func TestGameDTO(t *testing.T) {
 				g.players[0].DTO(),
 				g.players[1].DTO(),
 			},
+			Action:   "Start",
 			Round:    g.round,
 			Dealer:   false,
 			Damage:   g.damage,
@@ -471,6 +472,7 @@ func TestGameDTO(t *testing.T) {
 				g.players[0].DTO(),
 				g.players[1].DTO(),
 			},
+			Action:   "Shoot",
 			Round:    g.round,
 			Dealer:   true,
 			Damage:   g.damage,
@@ -489,6 +491,7 @@ func TestGameDTO(t *testing.T) {
 			t.Errorf("observer sees the wrong thing:\nwant %+v\ngot  %+v", want, got)
 		}
 	}
+	// TODO(zeph): many more tests about actions
 }
 
 func deref[T any, P ~*T](p P) (x T) {

game/item.go

@@ -20,9 +20,8 @@ func (i Item) Apply(g *Match) bool {
 	case ItemNone:
 		return false
 	case ItemLens:
-		if g.reveal {
-			return false
-		}
+		// Lenses are always used, even if they have no effect.
+		g.action = actLens
 		g.reveal = true
 		return true
 	case ItemCig:
@@ -31,10 +30,13 @@ func (i Item) Apply(g *Match) bool {
 			cur.hp++
 			// Cigs are always used, even if they have no effect.
 		}
+		g.action = actCig
 		return true
 	case ItemBeer:
 		g.popShell()
+		g.action = actBeer
 		if g.Empty() {
+			g.action = actBeerGameEnd
 			g.NextGame()
 		}
 		return true
@@ -43,12 +45,14 @@ func (i Item) Apply(g *Match) bool {
 		if opp.cuffs != Uncuffed {
 			return false
 		}
+		g.action = actCuff
 		opp.cuffs = Cuffed
 		return true
 	case ItemKnife:
 		if g.damage != 1 {
 			return false
 		}
+		g.action = actKnife
 		g.damage = 2
 		return true
 	default:
@@ -56,7 +60,8 @@ func (i Item) Apply(g *Match) bool {
 	}
 }
 
+var itemNames = [...]string{"", "🔍", "🚬", "🍺", "👮", "🔪"}
+
 func (i Item) String() string {
-	s := [...]string{"", "🔍", "🚬", "🍺", "👮", "🔪"}
-	return s[i]
+	return itemNames[i]
 }

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
+}