#34

backend/app/controllers/user_settings_controller.rb

@@ -0,0 +1,56 @@
+class UserSettingsController < ApplicationController
+  def show
+    return head :unauthorized unless current_user
+
+    render json: current_setting.serializable_hash
+  end
+
+  def update
+    return head :unauthorized unless current_user
+
+    raw_attributes = request.request_parameters
+    field_errors = validate_raw_attributes(raw_attributes)
+    return render_validation_error fields: field_errors if field_errors.present?
+
+    setting = current_setting
+    setting.assign_attributes(raw_attributes.slice(*Setting::EDITABLE_ATTRIBUTES))
+
+    if setting.save
+      render json: setting.serializable_hash, status: :ok
+    else
+      render_validation_error setting
+    end
+  end
+
+  private
+
+  def current_setting
+    current_user.setting || current_user.create_setting!(Setting.defaults)
+  end
+
+  def validate_raw_attributes raw_attributes
+    raw_attributes.each_with_object({ }) do |(key, value), errors|
+      unless Setting::EDITABLE_ATTRIBUTES.include?(key)
+        errors[key.to_sym] = ['不明な設定です．']
+        next
+      end
+
+      next if value_matches_type?(key, value)
+
+      errors[key.to_sym] = ['値の型が不正です．']
+    end
+  end
+
+  def value_matches_type? key, value
+    case Setting::TYPE_BY_ATTRIBUTE.fetch(key)
+    when :string
+      value.is_a?(String)
+    when :integer
+      value.is_a?(Integer)
+    when :boolean
+      value == true || value == false
+    else
+      false
+    end
+  end
+end