class Decidim::Meetings::QuestionResponsesCell

def answer_options_table_name
  @answer_options_table_name ||= Decidim::Meetings::AnswerOption.table_name
end

def answer_options_with_percentages
  # This query joins answer options with answer choices and answers
  # and returns for each answer option the count of times it has been answered
  # grouping by answer options and answers.
  #
  # This calculation is a bit complex because of multiple option answers
  question_answers_choices = Decidim::Meetings::AnswerOption.where(decidim_question_id: model.id)
                                                            .joins([choices: :answer])
                                                            .group(Arel.sql("#{answers_table_name}.id, #{answer_options_table_name}.id"))
                                                            .select(<<~SELECT
                                                              #{answer_options_table_name}.id AS id,
                                                              #{answer_options_table_name}.body,
                                                              #{answers_table_name}.id AS answer_id,
                                                              COUNT(decidim_answer_option_id) AS count
                                                            SELECT
                                                                   )
  # Extract the number of uniq answers by the answer_id attribute
  total_answers = question_answers_choices.map(&:answer_id).compact.uniq.size
  # A second grouping is necessary to count the number of answers for each answer_option id
  # and calculate the percentages
  options_with_percentages = []
  question_answers_choices.group_by(&:id).each do |_id, values|
    answers_count = values.sum(&:count)
    options_with_percentages << [values.first.body, calculate_and_format_percentage(answers_count, total_answers)]
  end
  options_with_percentages
end

def answers_table_name
  @answers_table_name ||= Decidim::Meetings::Answer.table_name
end

def calculate_and_format_percentage(part, total)
  format_percentage(calculate_percentage(part, total))
end

def calculate_percentage(part, total)
  total.zero? ? 0 : ((part.to_f / total) * 100).round(2)
end

def format_percentage(raw_percentage)
  "#{number_with_precision(raw_percentage, precision: 2, significant: true)}%"
end

def show
  render
end