# @note Inspired by Puma capistrano handlers
# @see https://github.com/seuros/capistrano-puma/blob/master/lib/capistrano/tasks/puma.rake
namespace :load do
  task :defaults do
    set :karafka_role, :app
    set :karafka_default_hooks, -> { true }
    set :karafka_env, -> { fetch(:karafka_env, fetch(:environment)) }
    set :karafka_pid, -> { File.join(shared_path, 'tmp', 'pids', 'karafka.pid') }
  end
end

namespace :deploy do
  before :starting, :check_karafka_hooks do
    invoke 'karafka:add_default_hooks' if fetch(:karafka_default_hooks)
  end
end

namespace :karafka do
  desc 'Stop Karafka'
  task :stop do
    on roles(fetch(:karafka_role)) do |host|
      within shared_path do
        # If there's no pidfile it means that Karafka is not running
        next unless test "cat #{fetch(:karafka_pid)}"

        # Send a kill signal to a given process
        execute "kill -INT `cat #{fetch(:karafka_pid)}`"

        # And wait until it finishes. We wait because we don't want to start next process until
        # the previous one is stopped. That way we won't have problems with Kafka registering and
        # deregistering processes from topics (although nothing bad would happen. It would just
        # take more time to rebalance)
        while true
          break unless test "cat #{fetch(:karafka_pid)}"
          info 'Waiting for Karafka to stop'
          sleep 5
        end
      end
    end
  end

  desc 'Start Karafka'
  task :start do
    on roles(fetch(:karafka_role)) do |host|
      within current_path do
        # We use all 3 because when combined with Sinatra/Rails it will use their parts as well
        # so we want to set proper env for any of them
        with(
          KARAFKA_ENV: fetch(:karafka_env),
          RAILS_ENV: fetch(:rails_env),
          RACK_ENV: fetch(:rack_env)
        )do
          execute :bundle, "exec karafka server -d -p #{fetch(:karafka_pid)}"
        end
      end
    end
  end

  desc 'Restart Karafka'
  task :restart do
    invoke 'karafka:stop'
    invoke 'karafka:start'
  end

  desc 'Status Karafka'
  task :status do
    on roles(fetch(:karafka_role)) do |host|
      if test "cat #{fetch(:karafka_pid)}"
        pid = capture "cat #{fetch(:karafka_pid)}"

        if test "ps -p #{pid} > /dev/null"
          info "Karafka is started: #{pid}"
        else
          error "Karafka is not started but pidfile exists"
        end
      else
        info "Karafka is not started"
      end
    end
  end

  task :add_default_hooks do
    after 'deploy:finished', 'karafka:restart'
  end
end