#!/usr/bin/env ruby

require 'fileutils'

class Sidekiqctl

  attr_reader :stage, :pidfile, :timeout

  def initialize(stage, pidfile, timeout)
    @stage = stage
    @pidfile = pidfile
    @timeout = timeout

    done('No pidfile given', :error) if !pidfile
    done("Pidfile #{pidfile} does not exist", :error) if !File.exist?(pidfile)
    done('Invalid pidfile content', :error) if pid == 0

    fetch_process

    begin
      send(stage)
    rescue NoMethodError
      done 'Invalid control command', :error
    end
  end

  def fetch_process
    Process.getpgid(pid)
  rescue Errno::ESRCH
    done "Process doesn't exist", :error
  end

  def done(msg, error = nil)
    puts msg
    exit(exit_signal(error))
  end

  def exit_signal(error)
    (error == :error) ? 1 : 0
  end

  def pid
    File.read(pidfile).to_i
  end

  def quiet
    `kill -USR1 #{pid}`
  end

  def stop
    `kill -TERM #{pid}`
    timeout.times do
      begin
        Process.getpgid(pid)
      rescue Errno::ESRCH
        FileUtils.rm_f pidfile
        done 'Sidekiq shut down gracefully.'
      end
      sleep 1
    end
    `kill -9 #{pid}`
    FileUtils.rm_f pidfile
    done 'Sidekiq shut down forcefully.'
  end

  def shutdown
    quiet
    stop
  end

end

stage = ARGV[0]
pidfile = ARGV[1]
timeout = ARGV[2].to_i
timeout = 10 if timeout == 0

Sidekiqctl.new(stage, pidfile, timeout)