# frozen_string_literal: true

# Genera resúmenes de información para poder mostrar estadísticas y se
# corre regularmente a sí misma.
class StatCollectionJob < PeriodicJob
  include RecursiveRollup

  STAT_NAME = 'stat_collection_job'

  def perform(site_id:, once: true)
    @site = Site.find site_id

    # Registrar que se hicieron todas las recolecciones
    stat = site.stats.create! name: STAT_NAME
    beginning = beginning_of_interval

    scope.rollup('builds', **options)

    scope.rollup('space_used', **options) do |rollup|
      rollup.average(:bytes)
    end

    scope.rollup('build_time', **options) do |rollup|
      rollup.average(:seconds)
    end

    # XXX: Es correcto promediar promedios?
    Stat::INTERVALS.reduce do |previous, current|
      opts = { interval_previous: previous, interval: current, beginning: beginning, dimensions: { site_id: site.id } }

      recursive_rollup(name: 'builds', **opts)
      recursive_rollup(name: 'space_used', operation: :average, **opts)
      recursive_rollup(name: 'build_time', operation: :average, **opts)

      current
    end

    stat.touch
    run_again! unless once
  end

  private

  # Los registros a procesar
  #
  # @return [ActiveRecord::Relation]
  def scope
    @scope ||= site.build_stats
                   .jekyll
                   .where('created_at >= ?', beginning_of_interval)
                   .group(:site_id)
  end

  # Las opciones por defecto
  #
  # @return [Hash]
  def options
    @options ||= { interval: starting_interval, update: true }
  end

  def stat_name
    STAT_NAME
  end
end