require "concurrent"
require "net/http"
require "aws-sdk"
require 'sqspoller/common/utils'
require 'sqspoller/logger/logger'

# QueuePoller responsible for polling batch message[s] using Aws::SQS::QueuePoller based on configured :max_number_of_messages and push to the task queue.
# If there is no messages available SQS it will keep polling based on :wait_time_seconds until the message arrives.
module SqsPoller
  module Poller
    class QueuePoller

      DEFAULT_SQS_WAIT_TIME_SECONDS = 20
      DEFAULT_SQS_MAX_NUMBER_OF_MESSAGES = 10

      def initialize(worker_name, queue_name, queue_config, task_queue, sqs_client, queue_url, counter)
        @worker_name = worker_name
        @queue_name = queue_name
        @queue_config = queue_config
        @task_queue = task_queue
        @wait_time_seconds = get_wait_time_seconds(@queue_config)
        @max_number_of_messages = get_max_number_of_messages(@queue_config)
        @sqs_client = sqs_client
        @queue_url = queue_url
        @logger = SqsPoller::Logger.get_new_logger("#{self.class.name}-#{@worker_name}")
        @counter = counter
      end

      def get_poller_stats
        @poller_stats
      end

      def run
        poller = Aws::SQS::QueuePoller.new(@queue_url, { client: @sqs_client })
        poller.before_request do |stats|
          @poller_stats = stats
        end
        poller.poll(skip_delete: true, :wait_time_seconds => @wait_time_seconds, :max_number_of_messages => @max_number_of_messages) do |messages|
          if @max_number_of_messages == 1
            messages = [messages]
          end
          messages.each { |message|
            task = {
              :message => message,
              :queue_name => @queue_name,
              :queue_time => SqsPoller::Common::Utils.get_current_time_in_millis,
              :index => @counter.increment
            }
            @task_queue.push task
          }
          @logger.info "Queued #{messages.size} messages from #{@queue_name}"
        end
      end

      def get_wait_time_seconds(queue_config)
        wait_time_seconds = queue_config[:wait_time_seconds]
        unless wait_time_seconds && wait_time_seconds >= 0 && wait_time_seconds <= DEFAULT_SQS_WAIT_TIME_SECONDS
          wait_time_seconds = DEFAULT_SQS_WAIT_TIME_SECONDS
        end
        wait_time_seconds
      end

      def get_max_number_of_messages(queue_config)
        max_number_of_messages = queue_config[:max_number_of_messages]
        unless max_number_of_messages && max_number_of_messages >= 0 && max_number_of_messages <= DEFAULT_SQS_MAX_NUMBER_OF_MESSAGES
          max_number_of_messages = DEFAULT_SQS_MAX_NUMBER_OF_MESSAGES
        end
        max_number_of_messages
      end

    end
  end
end