filter.rb

  def filter
    # receive params
    allowed_constant_params = %w(property_type listing_type_id rooms bathrooms location)
    allowed_varying_params = %w(price)

    query = ""
    allowed_constant_params.each do |param|
      unless params[param] == ""
        if query.empty?
          query.concat("SELECT * FROM properties WHERE #{param} = '#{params[param]}'")
        else
          query.concat(" AND #{param} = '#{params[param]}'")
        end
      end
    end

    #price recieves a string with "min,max" from the front end

    allowed_varying_params.each do |param|
      unless params[param] == ""
        min, max = params[param].delete('"').split(",")
        if query.empty?
          query.concat("SELECT * FROM properties WHERE CAST(price as Integer) >= #{min} AND CAST(price as Integer) <= #{max} ")
        else
          query.concat(" AND CAST(price as Integer) >= #{min} AND CAST(price as Integer) <= #{max}")
        end
      end
    end


    @properties = execute_statement(query)

    render json: @properties
  end