# frozen_string_literal: true

module Streams
  class AutoscalerJob
    include Sidekiq::Job

    sidekiq_options retry: 1, queue: "default"

    INTERVAL_SECS = ENV.fetch("STREAM_AUTOSCALE_INTERVAL_SECS", "60").to_i
    REDIS_CHAIN_KEY = "streams:autoscaler:chain"
    KICK_DEBOUNCE_KEY = "streams:autoscaler:kick"
    KICK_DEBOUNCE_SECS = ENV.fetch("STREAM_AUTOSCALE_KICK_DEBOUNCE_SECS", "5").to_i

    def self.ensure_chain
      return unless redis
      return if redis.get(REDIS_CHAIN_KEY)

      redis.set(REDIS_CHAIN_KEY, "1", ex: INTERVAL_SECS * 2)
      perform_in(INTERVAL_SECS)
    end

    # Kick immediato (es. NoCapacity / soft-free bassi). Debounce anti-flood Sidekiq.
    def self.kick!
      return false unless Streams::Autoscaler.enabled?
      return false unless redis
      return false unless redis.set(KICK_DEBOUNCE_KEY, "1", nx: true, ex: KICK_DEBOUNCE_SECS)

      perform_async
      true
    end

    def self.redis
      @redis ||= Redis.new(url: ENV.fetch("REDIS_URL", "redis://localhost:6379/0"))
    rescue Redis::CannotConnectError
      nil
    end

    def perform
      Streams::Autoscaler.reconcile!
    ensure
      self.class.redis&.set(REDIS_CHAIN_KEY, "1", ex: INTERVAL_SECS * 2)
      self.class.perform_in(INTERVAL_SECS)
    end
  end
end