フロントエンドプレイアブル

app/models/game_participant.rb

@@ -0,0 +1,52 @@
+class GameParticipant < ApplicationRecord
+  belongs_to :game
+  belongs_to :user
+
+  validates :status, inclusion: { in: %w[joined ready finished] }
+  validates :user_id, uniqueness: { scope: :game_id }
+  validates :power, uniqueness: { scope: :game_id }, allow_nil: true
+
+  # ステータス管理メソッド
+  def joined?
+    status == 'joined'
+  end
+
+  def ready?
+    status == 'ready'
+  end
+
+  def finished?
+    status == 'finished'
+  end
+
+  # パワー選択関連
+  def has_selected_power?
+    power.present?
+  end
+
+  def select_power!(power_name)
+    update!(power: power_name, status: 'ready')
+  end
+
+  # ゲーム参加メソッド
+  class << self
+    def join_game!(game, user, password = nil)
+      # パスワードチェック（プレイヤーモードの場合）
+      if game.player_mode? && game.password.present?
+        raise "Invalid password" unless game.password == password
+      end
+
+      # 既存参加チェック
+      if game.game_participants.exists?(user_id: user.id)
+        raise "Already joined this game"
+      end
+
+      # 定員チェック
+      if game.player_mode? && game.full?
+        raise "Game is full"
+      end
+
+      create!(game: game, user: user, joined_at: Time.current, status: 'joined')
+    end
+  end
+end