af83/chouette-core

class TimeZoneSelector
    def self.time_zone_for(user)
        TimeZoneSelector.new.tap do |selector|
            selector.user = user
        end.time_zone
    end

    attr_accessor :user

    def user_time_zone
        supported_time_zone(user&.time_zone)
    end

    def default_time_zone
        Time.zone_default.tzinfo.identifier
    end

  def time_zone
        user_time_zone || default_time_zone
  end

    private

    def supported_time_zone value
        ActiveSupport::TimeZone.new(value)&.tzinfo&.identifier
    rescue ArgumentError
    end
end