# frozen_string_literal: true

module Streams
  # Finestra notturna (default 02:00–07:00 Europe/Rome) in cui non devono restare CPX idle.
  module QuietHours
    DEFAULT_RANGE = "02:00-07:00"
    DEFAULT_TZ = "Europe/Rome"

    module_function

    def range_config
      ENV.fetch("STREAM_AUTOSCALE_QUIET_HOURS", DEFAULT_RANGE).to_s.strip
    end

    def time_zone_name
      ENV.fetch("STREAM_AUTOSCALE_QUIET_TZ", DEFAULT_TZ)
    end

    def configured?
      range_config.present? && range_config != "off" && range_config != "0"
    end

    def active?(now: Time.current)
      return false unless configured?

      zone = ActiveSupport::TimeZone[time_zone_name] || Time.find_zone!(time_zone_name)
      local = now.in_time_zone(zone)
      start_min, end_min = parse_range(range_config)
      return false if start_min.nil? || end_min.nil?

      current = local.hour * 60 + local.min
      if start_min <= end_min
        current >= start_min && current < end_min
      else
        # es. 22:00-06:00
        current >= start_min || current < end_min
      end
    rescue ArgumentError => e
      Rails.logger.warn("[Streams::QuietHours] invalid config: #{e.message}")
      false
    end

    def parse_range(raw)
      start_s, end_s = raw.split("-", 2).map { |p| p.to_s.strip }
      return [nil, nil] if start_s.blank? || end_s.blank?

      [parse_hhmm(start_s), parse_hhmm(end_s)]
    end

    def parse_hhmm(value)
      h, m = value.split(":", 2)
      hours = Integer(h)
      mins = Integer(m || 0)
      raise ArgumentError, "ora fuori range: #{value}" unless hours.between?(0, 23) && mins.between?(0, 59)

      hours * 60 + mins
    end
  end
end