better quiz access

app/models/candidate.rb

@@ -18,6 +18,14 @@ class Candidate < ApplicationRecord
     answers.where.not(answer: nil)
   end
 
+  def fetch_question qid
+    CandidateQuiz.new(id).fetch_question(qid).first
+  end
+
+  def my_quiz
+    CandidateQuiz.new(id).build_my_quiz
+  end
+
   private
 
     def generate_test_hash

app/workers/candidate_quiz.rb

@@ -0,0 +1,30 @@
+class CandidateQuiz
+  attr_reader :candidate_id
+
+  def initialize candidate_id
+    @candidate_id = candidate_id
+  end
+
+  def fetch_question qid
+    raw_quiz(qid).each_with_object([]) { |row, quiz| quiz << CandidateQuizQuestion.new(row) }
+  end
+
+  def build_my_quiz
+    raw_quiz.each_with_object([]) { |row, quiz| quiz << CandidateQuizQuestion.new(row) }
+  end
+
+  private
+
+    def raw_quiz qid = nil
+      question = qid.nil? ? "" : " and q.id = #{qid} "
+      sql = "select c.id candidate_id, q.quiz_id, q.id question_id, a.id answer_id, q.sort
+               , q.question, q.category, q.input_type, q.input_options, a.answer
+               , ifnull(a.saved, false) saved, ifnull(a.submitted, false) submitted , a.updated_at
+             from candidates c
+               inner join questions q on q.quiz_id = c.quiz_id
+               left join answers a on a.candidate_id = c.id AND a.question_id = q.id
+             where q.active = true and c.id = #{candidate_id} #{question}
+             order by c.id, q.sort;"
+      ActiveRecord::Base.connection.exec_query(sql)
+    end
+end

app/workers/candidate_quiz_question.rb

@@ -0,0 +1,56 @@
+class CandidateQuizQuestion
+  attr_reader :row
+
+  def initialize row
+    @row = row
+  end
+
+  def candidate_id
+    row["candidate_id"]
+  end
+
+  def quiz_id
+    row["quiz_id"]
+  end
+  alias to_i quiz_id
+
+  def question_id
+    row["question_id"]
+  end
+
+  def answer_id
+    row["answer_id"]
+  end
+
+  def question
+    row["question"]
+  end
+
+  def category
+    row["category"]
+  end
+
+  def input_type
+    row["input_type"]
+  end
+
+  def input_options
+    YAML.load(row["input_options"].to_s)
+  end
+
+  def answer
+    YAML.load(row["answer"].to_s) unless row['answer'].nil?
+  end
+
+  def saved
+    row["saved"]
+  end
+
+  def submitted
+    row["submitted"]
+  end
+
+  def updated_at
+    row["updated_at"]
+  end
+end