feat: game session, turn system, lobby, and room events

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

game/session.go

@@ -0,0 +1,133 @@
+package game
+
+import (
+	"sync"
+
+	"github.com/tolelom/catacombs/dungeon"
+	"github.com/tolelom/catacombs/entity"
+)
+
+type GamePhase int
+
+const (
+	PhaseExploring GamePhase = iota
+	PhaseCombat
+	PhaseShop
+	PhaseResult
+)
+
+type PlayerAction struct {
+	Type      ActionType
+	TargetIdx int
+}
+
+type ActionType int
+
+const (
+	ActionAttack ActionType = iota
+	ActionSkill
+	ActionItem
+	ActionFlee
+	ActionWait
+)
+
+type GameState struct {
+	Floor      *dungeon.Floor
+	Players    []*entity.Player
+	Monsters   []*entity.Monster
+	Phase      GamePhase
+	FloorNum   int
+	TurnNum    int
+	CombatTurn int // reset per combat encounter
+	SoloMode   bool
+	GameOver   bool
+	Victory    bool
+	ShopItems  []entity.Item
+}
+
+type GameSession struct {
+	mu       sync.Mutex
+	state    GameState
+	actions  map[string]PlayerAction // playerName -> action
+	actionCh chan playerActionMsg
+}
+
+type playerActionMsg struct {
+	PlayerName string
+	Action     PlayerAction
+}
+
+func NewGameSession() *GameSession {
+	return &GameSession{
+		state: GameState{
+			FloorNum: 1,
+		},
+		actions:  make(map[string]PlayerAction),
+		actionCh: make(chan playerActionMsg, 4),
+	}
+}
+
+// StartGame determines solo mode from actual player count at game start
+func (s *GameSession) StartGame() {
+	s.mu.Lock()
+	s.state.SoloMode = len(s.state.Players) == 1
+	s.mu.Unlock()
+	s.StartFloor()
+}
+
+func (s *GameSession) AddPlayer(p *entity.Player) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.state.Players = append(s.state.Players, p)
+}
+
+func (s *GameSession) StartFloor() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.state.Floor = dungeon.GenerateFloor(s.state.FloorNum)
+	s.state.Phase = PhaseExploring
+	s.state.TurnNum = 0
+
+	// Revive dead players at 30% HP
+	for _, p := range s.state.Players {
+		if p.IsDead() {
+			p.Revive(0.30)
+		}
+	}
+}
+
+func (s *GameSession) GetState() GameState {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.state
+}
+
+func (s *GameSession) SubmitAction(playerName string, action PlayerAction) {
+	s.actionCh <- playerActionMsg{PlayerName: playerName, Action: action}
+}
+
+// BuyItem handles shop purchases
+func (s *GameSession) BuyItem(playerName string, itemIdx int) bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.state.Phase != PhaseShop || itemIdx < 0 || itemIdx >= len(s.state.ShopItems) {
+		return false
+	}
+	item := s.state.ShopItems[itemIdx]
+	for _, p := range s.state.Players {
+		if p.Name == playerName && p.Gold >= item.Price {
+			p.Gold -= item.Price
+			p.Inventory = append(p.Inventory, item)
+			return true
+		}
+	}
+	return false
+}
+
+// LeaveShop exits the shop phase
+func (s *GameSession) LeaveShop() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.state.Phase = PhaseExploring
+	s.state.Floor.Rooms[s.state.Floor.CurrentRoom].Cleared = true
+}