init project

app/services/users/question_bank_service.rb

@@ -0,0 +1,99 @@
+class Users::QuestionBankService
+  attr_reader :user, :params
+
+  def initialize(user, params)
+    @user   = user
+    @params = params
+  end
+
+  def call
+    relations = class_name.classify.constantize.all
+
+    relations = category_filter(relations)
+    relations = type_filter(relations) if params[:type].present?
+
+    relations = relations.where(course_list_id: params[:course_list_id]) if params[:course_list_id].present?
+
+    custom_sort(relations, params[:sort_by], params[:sort_direction])
+  end
+
+  def course_lists
+    relation_name = class_name.underscore.pluralize.to_sym
+    course_lists = CourseList.joins(relation_name).where.not(relation_name => { id: nil })
+
+    category_condition =
+      case params[:object_type]
+      when 'normal' then { homework_type: 1 }
+      when 'group' then { homework_type: 3 }
+      when 'exercise' then { container_type: 'Exercise' }
+      when 'poll' then { container_type: 'Poll' }
+      when 'gtask', 'gtopic' then {}
+      else raise ArgumentError
+      end
+    course_lists = course_lists.where(relation_name => category_condition) if category_condition.present?
+
+    type_condition =
+      case params[:type]
+      when 'personal' then { user_id: user.id }
+      when 'publicly' then { is_public: true }
+      else {}
+      end
+    course_lists = course_lists.where(relation_name => type_condition) if type_condition.present?
+
+    course_lists.distinct.select(:id, :name)
+  end
+
+  private
+
+  def class_name
+    @_class_name ||= begin
+      case params[:object_type]
+      when 'normal', 'group'  then 'HomeworkBank'
+      when 'exercise', 'poll' then 'ExerciseBank'
+      when 'gtask'            then 'GtaskBank'
+      when 'gtopic'           then 'GtopicBank'
+      else raise ArgumentError
+      end
+    end
+  end
+
+  def category_filter(relations)
+    case params[:object_type]
+    when 'normal' then
+      relations.where(homework_type: 1)
+    when 'group' then
+      relations.where(homework_type: 3)
+    when 'exercise' then
+      relations.where(container_type: 'Exercise')
+    when 'poll' then
+      relations.where(container_type: 'Poll')
+    when 'gtask', 'gtopic' then
+      relations.all
+    else
+      raise ArgumentError
+    end
+  end
+
+  def type_filter(relations)
+    case params[:type]
+    when 'personal' then relations.where(user_id: user.id)
+    when 'publicly' then relations.where(is_public: true)
+    else relations
+    end
+  end
+
+  def custom_sort(relations, sort_by, sort_direction)
+    case sort_by
+    when 'updated_at' then
+      relations.order("updated_at #{sort_direction}, id #{sort_direction}")
+    when 'name' then
+      relations.order("CONVERT(name USING gbk) COLLATE gbk_chinese_ci #{sort_direction}")
+    when 'contributor' then
+      order_sql = "CONVERT (users.lastname USING gbk) COLLATE gbk_chinese_ci #{sort_direction},"\
+                  " CONVERT (users.firstname USING gbk) COLLATE gbk_chinese_ci #{sort_direction}"
+      relations.joins(:user).where(users: { status: 1 }).order(order_sql)
+    else
+      relations
+    end
+  end
+end