search params processor for sliders

villages_slider_filter.rb

class VillagesSliderFilter

  VILLAGE_SORT_PARAMS = { price: { range: true },
                          distance: { range: false },
                          area_price: { range: false },
                          land_price: { range: true } }

  VILLAGE_JOINS = [:builders, :village_odds, :building_types, :directions]

  def initialize(params)
    @params = params
  end
  
  def process_params
    # remove empty hashes, arrays, etc from params
    clear_params_hash(@params)
  
    VILLAGE_SORT_PARAMS.each do |key, param|
      if param[:range]
        instance_variable_set("@#{key.to_s}_start", @params.delete("#{key}_start".to_sym))
        instance_variable_set("@#{key.to_s}_stop", @params.delete("#{key}_stop".to_sym))
      else
        instance_variable_set("@#{key}", @params.delete(key))
      end
    end
  end

  def search
    villages = Village.joins(VILLAGE_JOINS).where(@params)
    VILLAGE_SORT_PARAMS.each do |key, param|
      start =  instance_variable_get("@#{key}_start")
      stop =  instance_variable_get("@#{key}_stop")

      if start && stop
        if param[:range]
          villages = villages.where("#{key}_start >= ? AND #{key}_stop <= ?", start, stop)
        else
          villages = villages.where("#{key} >= ? AND #{key} <= ?", start, stop)
        end
      end
    end
    return villages.uniq
  end

  def clear_params_hash(hash)
    hash.delete_if do |k, v|
      if v.empty?
        true
      else
        if v.is_a? Hash
          clear_params_hash(v).empty?
        elsif v.is_a? Array
          clear_params_array(v).empty?
        end
      end
    end
  end

  def clear_params_array(array)
    array.delete_if{|value| value.empty?}
  end

end