class StackSynchronizer
  include PutsAndFlush
  attr_reader :out, :stack

  def initialize(stack, out)
    @stack, @out = stack, out
    @printed_events = []
  end

  def sync
    puts_and_flush "Syncing stack '#{stack.id}'..."

    # 5 tries each 5 seconds, then 200 tries each 10 seconds
    sleep_times = [5]*5 + [10]*400

    sleep_times.each do |sleep_time|
      sleep sleep_time
      stack.sync_details!
      print_new_events
      case stack.stack_status
      when 'CREATE_IN_PROGRESS', 'ROLLBACK_IN_PROGRESS'
      when 'CREATE_COMPLETE'
        ::Devops::Db.connector.stack_update(stack)
        puts_and_flush "Stack '#{stack.id}' status is now #{stack.stack_status}"
        return 0
      when 'ROLLBACK_COMPLETE'
        puts_and_flush "Stack '#{stack.id}' status is rolled back"
        return error_code(:stack_rolled_back)
      else
        puts_and_flush "Unknown stack status: '#{stack.stack_status}'"
        return error_code(:unkown_status)
      end
    end
    puts_and_flush "Stack hasn't been synced in #{sleep_times.inject(&:+)} seconds."
    error_code(:timeout)
  rescue StandardError => e
    DevopsLogger.logger.error e.message
    puts_and_flush "Error: #{e.message}\n#{e.backtrace.join("\n")}"
    error_code(:error)
  end

  def reason_from_error_code(code)
    error_codes.key(code)
  end

  private

  def error_code(reason)
    error_codes.fetch(reason)
  end

  def error_codes
    {
      stack_rolled_back: 1,
      unkown_status: 2,
      timeout: 3,
      error: 5
    }
  end


  def print_new_events
    stack.events.each do |event|
      unless @printed_events.include?(event["event_id"])
        @printed_events << event["event_id"]
        out.puts "#{event["timestamp"]} - #{event["status"]}: #{event["reason"]}"
      end
    end
    out.flush
  end
end