Sorting sequences

Sorting Sequences.rb

# from sequences_controller.rb
  def sort
    sequence_groups = []
    
    #turn hash into array
    if params[:sequence_groups] 
      params[:sequence_groups].each do |k, v|
        sequence_groups << v
      end
      array = Sequence.assign_group_id(sequence_groups)
    elsif params[:sequences]
      array = []
      params[:sequences].each do |s|
        sequence_id = s.to_s.gsub("sequence_", "")        
        array << sequence_id
      end
    end
    #assign group_ids, then reorder the sequences
    sequences = Sequence.find_sequences_from_array(array)
    Sequence.reorder_siblings(sequences)
    
    @course = Course.find(sequences[0].course_id)
    render :nothing => true
  end



# from sequence.rb  
  def self.assign_group_id(sequence_groups)
    sequence_ids_array = []
    sequence_groups.each do |sg|
      group_id = sg.keys[0].to_s.gsub('sequence_group_', '')
      sg.values[0].each do |s|
        sequence_id = s.to_s.gsub("sequence_", "")        
        Sequence.set(sequence_id, :sequence_group_id => group_id )
        sequence_ids_array << sequence_id
      end
    end
    return sequence_ids_array
  end
  
  def self.find_sequences_from_array(sequence_ids_array)
    sequence_array = []
    sequence_ids_array.each do |r|
      sequence_array << Sequence.find(r)
    end
    return sequence_array
  end
  
  
  def self.reorder_siblings(siblings)
    if siblings.first.parent.nil?
      siblings.each_with_index do |s, i|
        Sequence.set(s.id, :root_position => i + 1 )
      end
      siblings.group_by(&:unit_type_id).each do |unit_type, sequences|
        sequences.each_with_index do |s, i|
          Sequence.set(s.id, :position => i + 1)
        end
      end
    else
      siblings.each_with_index do |s,i|
        Sequence.set(s.id, :position => i + 1)
      end
    end  
  end