# frozen_string_literal: true

# rubocop:disable Rails/Output
# rubocop:disable Style/GuardClause
class CheckLegacyTables < ActiveRecord::Migration[5.2]
  class Answer < ApplicationRecord
    self.table_name = :decidim_surveys_survey_answers
  end

  class AnswerChoice < ApplicationRecord
    self.table_name = :decidim_surveys_survey_answer_choices
  end

  class AnswerOption < ApplicationRecord
    self.table_name = :decidim_surveys_survey_answer_options
  end

  class Question < ApplicationRecord
    self.table_name = :decidim_surveys_survey_questions
  end

  def up
    if tables_exists.any?
      if tables_exists.all?
        migrate_legacy_data if Question.any?
      else
        puts "Some legacy surveys tables exist but not all. Have you migrated all the data?"
        puts "Migrate or backup your data and then remove the following raise statement to continue with the migrations (that will remove surveys legacy tables)"
        puts "For migrating your data you can do that with the command:"
        puts "bundle exec rake decidim_surveys:migrate_data_to_decidim_forms"
        raise "ERROR:  there's the risk to loose legacy information from old surveys!"
      end
    end
  end

  def tables_exists
    @tables_exists ||= [Answer, AnswerChoice, AnswerOption, Question].collect { |model| ActiveRecord::Base.connection.table_exists? model.table_name }
  end

  def migrate_legacy_data
    puts "Migrating data from decidim_surveys tables to decidim_forms tables..."
    ActiveRecord::Base.transaction do
      Decidim::Surveys::Survey.find_each do |survey|
        puts "Migrating survey #{survey.id}..."
        if survey.questionnaire.present?
          puts("already migrated at questionnaire #{survey.questionnaire.id}")
          next
        end

        questionnaire = ::Decidim::Forms::Questionnaire.create!(
          questionnaire_for: survey,
          title: survey.title,
          description: survey.description,
          tos: survey.tos,
          published_at: survey.published_at,
          created_at: survey.created_at,
          updated_at: survey.updated_at
        )

        Question.where(decidim_survey_id: survey.id).find_each do |survey_question|
          puts "Migrating question #{survey_question.id}..."

          question = ::Decidim::Forms::Question.create!(
            questionnaire: questionnaire,
            position: survey_question.position,
            question_type: survey_question.question_type,
            mandatory: survey_question.mandatory,
            body: survey_question.body,
            description: survey_question.description,
            max_choices: survey_question.max_choices,
            created_at: survey_question.created_at,
            updated_at: survey_question.updated_at
          )

          # A hash with the old answer_option id as key, and the new form answer option as value
          answer_option_mapping = {}

          AnswerOption.where(decidim_survey_question_id: survey_question.id).find_each do |survey_answer_option|
            answer_option_mapping[survey_answer_option.id] = ::Decidim::Forms::AnswerOption.create!(
              question: question,
              body: survey_answer_option.body,
              free_text: survey_answer_option.free_text
            )
          end

          Answer.where(decidim_survey_id: survey.id, decidim_survey_question_id: survey_question.id).find_each do |survey_answer|
            answer = ::Decidim::Forms::Answer.new(
              questionnaire: questionnaire,
              question: question,
              decidim_user_id: survey_answer.decidim_user_id,
              body: survey_answer.body,
              created_at: survey_answer.created_at,
              updated_at: survey_answer.updated_at
            )

            AnswerChoice.where(decidim_survey_answer_id: survey_answer.id).find_each do |survey_answer_choice|
              answer.choices.build(
                answer_option: answer_option_mapping[survey_answer_choice.decidim_survey_answer_option_id],
                body: survey_answer_choice.body,
                custom_body: survey_answer_choice.custom_body,
                position: survey_answer_choice.position
              )
            end

            answer.save!
          end
        end
      end
    end
  end
end

# rubocop:enable Style/GuardClause
# rubocop:enable Rails/Output