require "logger"
require "concurrent"
require "net/http"
require "sqspoller/worker_task"
require "sqspoller/common/ring_buffer"
require "sqspoller/process/task_finalizer"
require "sqspoller/common/utils"
require "sqspoller/metrics/sqs_poller_metrics"

# This Worker keep polls the task queue (SizedQueue with blocking) and delegate the message the message handler.
# Once message is process based on its status will send to task finalizer if the message is successfully handled.
# else it will ignore the message. Based on message visibility timeout in SQS it will reappear and processed.
module SqsPoller
  module Process
    class Worker

      def initialize(worker_name, task_queue, task_finalizer, message_handler)
        @worker_name = worker_name
        @task_queue = task_queue
        @message_handler = message_handler
        @task_finalizer = task_finalizer
        @logger = SqsPoller::Logger.get_new_logger("#{self.class.name}-#{@worker_name}")
      end

      def run
        loop do
          task = @task_queue.pop
          message = task[:message]
          success = false
          timer = SqsPoller::Common::Utils.start_timer
          message_type= "UNKNOWN"
          begin
            @logger.debug "Starting worker task for message: #{message.message_id}"
            message_type = @message_handler.handle(message.body, message.message_id)
            @logger.debug "Finished worker task for message: #{message.message_id}"
            success = true
          rescue Exception => e
            @logger.error "Caught error: #{e.message}, #{e.backtrace.join("\n")} for message id: #{message.message_id}, body: #{message.body}"
          end
          elapsed_time = timer.stop
          queue_wait_time = timer.start_time - task[:queue_time]
          @logger.info "Task Completed queue_name: #{task[:queue_name]}, message_id: #{message.message_id}, message_type: #{message_type}, elapsed_time: #{elapsed_time}, queue_wait_time: #{queue_wait_time} message_count: #{task[:index]}"
          SqsPoller::Metrics.record(task, success, timer, elapsed_time)
          @task_finalizer.finalize(task) if success
        end
      end

    end
  end
end