require 'mail'
require 'thread'
require 'parallel'
require 'benchmark'


Mail.defaults do
  delivery_method :smtp, options
end

POOL_SIZE = 300
# multi treaded (ish) version is the fastest of all the versions
def send_test_emails_tp(mailbox_accounts, email_body, n=1)
  jobs = Queue.new
  mailbox_accounts.each do |mailbox|
    puts " Queueing emails from #{mailbox}"
    n.times{|i| jobs.push({i: (i+1), mailbox: mailbox})}
  end

  workers = (POOL_SIZE).times.map do
    Thread.new do
      begin
        while args = jobs.pop(true)
          Mail.deliver do
            to args[:mailbox]
            from "desk@stresstestmatic.com"
            subject "Postman Stress test email #{args[:i]} of #{n} from #{args[:mailbox]}"
            body ("Stress Test email #{args[:i]} Body from #{args[:mailbox]} \n" + email_body)
          end
          print '.'
        end
      rescue ThreadError
      end
    end
  end

  workers.map(&:join)
  puts ' Done'
end

# send n emails to mailbox accounts with email_body
def send_test_emails(mailbox_accounts, email_body, n=1)
  mailbox_accounts.each do |mailbox|
    puts " Sending Test emails for Mailbox: #{mailbox}"
    (1..n).each do |i|
      Mail.deliver do
        to mailbox
        from "desk@stresstestmatic.com"
        subject "Postman Stress test email #{i} from #{mailbox}"
        body ("Stress Test email #{i} Body from #{mailbox} \n" + email_body)
      end
      print '.'
    end
  end
  puts ' Done'
end

PROCESS_COUNT = 2
# multi process
def send_test_emails_mp(mailbox_accounts, email_body, n=1)
  mb = mailbox_accounts.map do |mailbox|
    puts " Queueing emails from #{mailbox}"
    (0..(n-1)).map{|i| {i: (i+1), mailbox: mailbox}}
  end.flatten

  Parallel.each(mb, in_processes: PROCESS_COUNT) {|args|
    Mail.deliver do
      to args[:mailbox]
      from "user@stresstestmatic.com"
      subject "Stress test email #{args[:i]} of #{n} from #{args[:mailbox]}"
      body ("Stress Test email #{args[:i]} Body from #{args[:mailbox]} \n" + email_body)
    end
    print '.'
  }
end

# multi process thread-pool
def send_test_emails_mp_tp(mailbox_accounts, email_body, n=1)
  Parallel.each(mailbox_accounts.each_slice((mailbox_accounts.count/PROCESS_COUNT)).to_a, in_processes: PROCESS_COUNT) {|batch|
    send_test_emails_tp(batch, email_body, n)
  }
end

# Benchmark.measure { send_test_emails_tp(mailbox_accounts, email_body, 101) }