20110509100020_merge_adhd.rb

class MergeAdhd < ActiveRecord::Migration
  def self.up
    adhd1 = RoquaQuestionnaire.find_by_key "adhd"
    adhd1_bulk = RoquaQuestionnaire.find_by_key "adhd_bulk"
    adhd2 = RoquaQuestionnaire.find_by_key "adhd2"
    adhd2_bulk = RoquaQuestionnaire.find_by_key "adhd2_bulk"
    
    [adhd1, adhd1_bulk, adhd2, adhd2_bulk].each do |q|
      # Prefix all values.keys with questionnaire.key
      q.answers.each do |answer|
        result = answer.values.map do |key, value|
          ["#{q.key}_#{key}", value]
        end
        answer.values = Hash[*result.flatten]
        answer.save
      end
      
      # Update q.vars to reflect the new prefix
      q.vars = q.variables.map{|i| "#{q.key}_#{i}"}

      # Update q.to_bulk to reflect the new prefix
      q.to_bulk_will_change!
      result = q.to_bulk.map{|key, value| ["#{q.key}_#{key}", "#{q.key}_#{value}"] }
      q.to_bulk = Hash[*result.flatten]
      q.save
    end

    # Find pairs
    by_patient = {}
    [adhd1, adhd1_bulk, adhd2, adhd2_bulk].each do |q|
      q.answers.each do |answer|
        next unless answer.active
        by_patient[answer.subject_id] ||= {}
        by_patient[answer.subject_id][answer.meas_instance_id] ||= []
        by_patient[answer.subject_id][answer.meas_instance_id] << answer
      end
    end

    # Sanity check
    by_patient.each do |subject_id, meas_instances|
      meas_instances.each do |meas_instance_id, answers|
        raise "Too many answers for #{subject_id} -> #{meas_instance_id}" if answers.size > 2
      end
    end

    # Merge pairs
    by_patient.each do |subject_id, meas_instances|
      meas_instances.each do |meas_instance_id, answers|
        RoquaAnswer.transaction do
          one = answers.find{|i| [adhd1.id, adhd1_bulk.id].include?(i.questionnaire_id) }
          two = answers.find{|i| [adhd2.id, adhd2_bulk.id].include?(i.questionnaire_id) }
          one.values = one.values.merge(two.values)
          one.save!
          two.active = false
          two.save!
        end
      end
    end

    # Disable the now unused adhd2 questionnaire
    adhd2.active = false;      adhd2.save
    adhd2_bulk.active = false; adhd2_bulk.save

    # Convert to QubyQuestionnaire
    adhd1.convert_to_quby_questionnaire("adhd")
  end

  def self.down
#    raise IrreversibleMigration
  end
end