UserSearcher.rb

module UserSearcher
  def self.call(params = {})
    scope = ::User.active
  
    # by id
    scope = scope.find(params['id']).to_a if params['id'].present?
  
    # simple fields
    %w[first_name last_name email city].each do |item|
      next unless params[item].present?
      scope = scope.where(item => params[item])
    end
    
    if params['gender'].present? and %w[male female].include?(params['gender'])
      scope = scope.where(gender: params['gender'])
    end

    # complex fields
    if params['birthdate_before'].present?
      scope = scope.where(
        birthdate: { :$lte => Date.parse(params['birthdate_before']) }
      )
    end

    if params['birthdate_after'].present?
      scope = scope.where(
        birthdate: { :$gte => Date.parse(params['birthdate_after']) }
      )
    end

    scope
  end
end