#41

backend/app/controllers/gekanator_question_suggestions_controller.rb

@@ -0,0 +1,19 @@
+class GekanatorQuestionSuggestionsController < ApplicationController
+  def create
+    return head :not_found unless current_user&.admin?
+
+    game = GekanatorGame.find_by(id: params.require(:gekanator_game_id))
+    return head :not_found unless game
+
+    suggestion = GekanatorQuestionSuggestion.new(
+        gekanator_game: game,
+        user: current_user,
+        question_text: params.require(:question_text))
+
+    if suggestion.save
+      render json: { id: suggestion.id }, status: :created
+    else
+      render_validation_error suggestion
+    end
+  end
+end

backend/app/models/gekanator_game.rb

@@ -2,6 +2,9 @@ class GekanatorGame < ApplicationRecord
   belongs_to :user
   belongs_to :guessed_post, class_name: 'Post'
   belongs_to :correct_post, class_name: 'Post'
+  has_many :question_suggestions,
+           class_name: 'GekanatorQuestionSuggestion',
+           dependent: :delete_all
 
   validates :answers, presence: true
   validates :question_count, numericality: { greater_than_or_equal_to: 0 }

backend/app/models/gekanator_question_suggestion.rb

@@ -0,0 +1,21 @@
+class GekanatorQuestionSuggestion < ApplicationRecord
+  MAX_QUESTIONS_PER_GAME = 1
+
+  belongs_to :gekanator_game
+  belongs_to :user
+
+  validates :question_text, presence: true, length: { maximum: 1000 }
+  validates :processed, inclusion: { in: [true, false] }
+  validate :question_suggestion_limit_per_game, on: :create
+
+  private
+
+  def question_suggestion_limit_per_game
+    return if gekanator_game_id.blank?
+
+    count = GekanatorQuestionSuggestion.where(gekanator_game_id:).count
+    if count >= MAX_QUESTIONS_PER_GAME
+      errors.add(:base, '質問追加数を超えてゐます．')
+    end
+  end
+end

backend/config/routes.rb

@@ -65,6 +65,9 @@ Rails.application.routes.draw do
 
   namespace :gekanator do
     resources :games, only: [:create], controller: '/gekanator_games'
+    resources :question_suggestions,
+              only: [:create],
+              controller: '/gekanator_question_suggestions'
   end
 
   resources :users, only: [:create, :update] do

backend/db/migrate/20260608000000_create_gekanator_question_suggestions.rb

@@ -0,0 +1,14 @@
+class CreateGekanatorQuestionSuggestions < ActiveRecord::Migration[8.0]
+  def change
+    create_table :gekanator_question_suggestions do |t|
+      t.references :gekanator_game,
+                   null: false,
+                   foreign_key: { on_delete: :cascade }
+      t.references :user, null: false, foreign_key: true
+      t.text :question_text, null: false
+      t.boolean :processed, null: false, default: false
+
+      t.timestamps
+    end
+  end
+end

backend/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_06_07_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_06_08_000000) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -63,6 +63,17 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_07_000000) do
     t.check_constraint "`question_count` >= 0", name: "chk_gekanator_games_question_count_nonnegative"
   end
 
+  create_table "gekanator_question_suggestions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.bigint "gekanator_game_id", null: false
+    t.bigint "user_id", null: false
+    t.text "question_text", null: false
+    t.boolean "processed", default: false, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["gekanator_game_id"], name: "index_gekanator_question_suggestions_on_gekanator_game_id"
+    t.index ["user_id"], name: "index_gekanator_question_suggestions_on_user_id"
+  end
+
   create_table "ip_addresses", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.binary "ip_address", limit: 16, null: false
     t.datetime "banned_at"
@@ -496,6 +507,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_07_000000) do
   add_foreign_key "gekanator_games", "posts", column: "correct_post_id"
   add_foreign_key "gekanator_games", "posts", column: "guessed_post_id"
   add_foreign_key "gekanator_games", "users"
+  add_foreign_key "gekanator_question_suggestions", "gekanator_games", on_delete: :cascade
+  add_foreign_key "gekanator_question_suggestions", "users"
   add_foreign_key "material_versions", "materials"
   add_foreign_key "material_versions", "materials", column: "parent_id"
   add_foreign_key "material_versions", "tags"