require 'timeout'
# encoding: utf-8
module Sinatra
  module ScheduleHelper

    @@scheduler = Rufus::Scheduler.new

    def check_file_locked?(specific_lock_file=nil)
      return false if specific_lock_file.nil?
      f = File.open("/tmp/#{specific_lock_file}", File::CREAT)
      Timeout::timeout(0.001) { f.flock(File::LOCK_EX) }
      f.flock(File::LOCK_UN)
      false
    rescue 
      true
    ensure
      unless f.nil?
        f.close
      end
    end

    def schedule_every(time,specific_lock_file) 
      @@scheduler.every time do

        unless check_file_locked?(specific_lock_file)
          begin
            file_path = specific_lock_file.nil?? "/tmp/schedule.lock" : "/tmp/#{specific_lock_file}";
            f = File.open(file_path, "w+")
            # if file was previosly locked then flock throw a exception
            f.flock(File::LOCK_EX)
            ten_minutes = 600
            # if the process overcome ten minutes, the timeout api throw a exception
            Timeout::timeout(ten_minutes) do 

              begin
                yield
              rescue StandardError => error
                title = error.message.split(':')[0].gsub('#<','');
                message = error.backtrace.join(',');
                NotificationSender.instance.send_error(nil,title,message)
              end

            end
          ensure
            unless f.nil?
              f.flock(File::LOCK_UN)
              f.close
            end
          end
        end

      end
    end

    def schedule_at(cron_expression,specific_lock_file) 
      @@scheduler.cron cron_expression do

        unless check_file_locked?(specific_lock_file)
          begin
            file_path = specific_lock_file.nil?? "/tmp/schedule.lock" : "/tmp/#{specific_lock_file}";
            f = File.open(file_path, "w+")
            # if file was previosly locked then flock throw a exception
            f.flock(File::LOCK_EX)
            ten_minutes = 600
            # if the process overcome ten minutes, the timeout api throw a exception
            Timeout::timeout(ten_minutes) do 

              begin
                yield
              rescue error
                title = error.message.split(':')[0].gsub('#<','');
                message = error.backtrace.join(',');
                NotificationSender.instance.send_error(nil,title,message)
              end

            end
          ensure
            unless f.nil?
              f.flock(File::LOCK_UN)
              f.close
            end
          end
        end

      end
    end
  end

  register ScheduleHelper
end