# frozen_string_literal: true

namespace :vns do
  desc 'Benchmarks the efficiency of the VNS implementation'
  task benchmark: :environment do
    ActsAsTenant.with_tenant(Wedding.first) do

      iterations = 10

      guests = Guest.potential

      Rails.logger.info "There are #{guests.count} potential guests"

      time_acc = 0
      solution_acc = 0

      hierarchy = AffinityGroupsHierarchy.new

      iterations.times do |i|
        engine = VNS::Engine.new

        engine.add_perturbation(Tables::Swap)
        engine.add_perturbation(Tables::Shift)

        initial_solution = Tables::Distribution.new(min_per_table: 8, max_per_table: 10, hierarchy:)

        random = Random.new(i)
        initial_solution.random_distribution(guests.shuffle(random:), random:)

        engine.initial_solution = initial_solution

        engine.target_function(&:discomfort)

        start_time = Time.now
        
        solution = engine.run

        elapsed = Time.now - start_time

        time_acc += elapsed
        solution_acc += solution.discomfort

        Rails.logger.info "[#{elapsed}] Best solution found with discomfort: #{solution.discomfort}"
      end

      Rails.logger.info "Average time: #{time_acc / iterations} seconds"
      Rails.logger.info "Average discomfort: #{solution_acc / iterations}"
    end
  end
end