require 'rubygems'
require 'thread'
require 'uri'
require 'net/http'
require 'logger'
require 'json'
require 'digest/md5'
require 'shellwords'
require 'trollop'
require 'socket'

module KL
	module Agent
		
		PIDFile = "#{KL.home}/kldockeragent.pid"

		@@notifier_engine = KL::Notifier.new
		@@web_server = KL::Server.new

		@@global_app_uuid = KL.getApplicationId

		# Start the agent.
		#
		# options:
		#	:daemon   => true if running as a daemon, false if as a console application
		#	:port     => port of web server will listen to
		#	:ssl      => set true to enable HTTPS
		#	:certfile => certificate file path for HTTPS
		#	:keyfile  => key file path for HTTPS
		#
		def self.start(opts={})
			KL.logger.info "[main] Starting agent: #{KL::Agent.getUUID}"
			puts "Starting agent..."

			@@config = opts
			Process.daemon if opts[:daemon] and not opts[:mock]
			begin
			 	if not is_windows
					# trap signal
					['INT', 'HUP'].each do |signal|
						trap(signal) {
							KL.logger.info "[main] Shutting down services..."
							web_server.stop
							notifier_engine.stop
							loop do
								break if notifier_engine.status == :stopped
								sleep 1
							end

							self.close
						}
					end
				end

			 	File.open(PIDFile, 'w', 0644) { |f| f.write($$.to_s) }

			 	notifier_engine.start
			 	web_server.start

			 	@@main_enabled = true
			 	while @@main_enabled; end

			rescue Exception => e
			 	KL.logger.error "Starting the agent [Failed] #{e}\n#{e.backtrace.join("\n")}"
			 	raise e
			end
		end

		# Stop the agent's daemon.
		#
		def self.stop(opts={})
			 begin
			 	pid = File.read(PIDFile).to_i
			 	puts "Stopping agent with PID #{pid}..."
			 	Process.kill 'HUP', pid

				if not opts[:mock]
					begin
						sleep (KL::Notifier::SleepTime + 0.5)

						Process.kill 0, pid
						KL.logger.info "[main] Agent is still running."
						puts "Agent is still running."

						KL.logger.info "[main] Killing agent."
						puts "Killing agent."
						Process.kill 9, pid
					rescue
						KL.logger.info "[main] Agent has stopped."
						puts "Agent has stopped."
						File.delete(PIDFile) if File.exist?(PIDFile)
					end
				end

			 rescue
			 	puts "Agent is not running."
			 	File.delete(PIDFile) if File.exist?(PIDFile)
			 end
		end

		def self.pid
			begin
				pid = File.read(PIDFile).to_i
				return pid if Process.kill 0, pid
			rescue
			end
			nil
		end

		# Return agent's PID if it is running, otherwise nil.
		#
		def self.status
			if pid.nil?
				puts "Agent is not running."
			else
				puts "Agent is running with PID #{pid}"
			end
		end

		def self.is_windows
			(RbConfig::CONFIG['host_os'] =~ /mswin|mingw|cygwin/)
		end

		def self.is_linux
			(RbConfig::CONFIG['host_os'] =~ /linux/)
		end

		def self.notifier_engine
			@@notifier_engine
		end

		def self.web_server
			@@web_server
		end

		def self.close
			KL.logger.info "[main] Stopping agent..."
		 	@@main_enabled = false
		end

		def self.getUUID
			@@global_app_uuid
		end

		def self.getVersion
			File.read(File.dirname(__FILE__) + '/../../VERSION').strip
		end

	end
end