gistfile1.rb

class WallModuleQuery
  def initialize(parent, relation = WallModule.scoped)
    valid_parents = [Client, BrandTemplate, Store]
    raise ArgumentError unless valid_parents.any? { |p|
      parent.is_a?(p)
    }
    @parent = parent
    @relation = relation
    @draft = true
    @states = ['published', 'enabled']
    @order_fields = ['size', 'sector', 'position']
    @datetime = nil
  end

  def with_state(state)
    @relation = @relation.where(:state => valid_states_for(state.to_sym)
    self
  end

  def datetime(*arg)
    # TODO: add criteria to relation
    self
  end


  def draft(value)
    # TODO: add criteria to relation
    self
  end

  def visible
    @relation = @relation.where('visible_at <= ? AND visible_until >= ?',
      @datetime, @datetime)
    self
  end

  def find_each(options={}, datetime=nil, &block)
    @relation = @relation.list_wall_modules.with_states.visible
    if @draft
      @relation = @relation.draft_ordered_by
    else
      @relation = @relation.ordered_by
    end
    @relation.find_each(&block)
  end

  private

  def valid_states_for(option)
    case option
    when :all
      ['published', 'enabled', 'pending', 'disabled', 'hidden']
    when :published_only
      ['published', 'pending']
    when :disabled
      ['disabled', 'pending']
    when :enabled
      ['enabled']
    when :hidden
      ['hidden']
    when :pending
      ['pending']
    else # draft_mode
      ['published', 'enabled']
    end
  end

  def list_wall_modules
    @relation = @relation.where(:parent_type => @parent.class.name,
      :parent_id => @parent.id)
  end
end