module ExceptionHandler

	#Message
	class Message

		# Init
		def initialize(app)
			@app = app
		end

		#Error
		def call(env)
			@app.call(env)

		rescue Exception => exception
			request = ActionDispatch::Request.new(env)
			controller = env['action_controller.instance']

			ExceptionHandler::Parser.new(exception, request, controller).save unless self.ignore?(exception, request)
			raise exception
		end

		#Ignore
		def ignore?(exception, request, ignored = {})
			ignored[:errors] = [ActionController::RoutingError, AbstractController::ActionNotFound, ActiveRecord::RecordNotFound]
			ignored[:bots]   = /\b(Baidu|Gigabot|Googlebot|libwww-per|lwp-trivial|msnbot|SiteUptime|Slurp|Wordpress|ZIBB|ZyBorg|Yandex|Jyxobot|Huaweisymantecspider|ApptusBot)\b/i

			return true if ignored[:errors].include?(exception.class) && request.referer.blank?
			return true if request.user_agent =~ ignored[:bots]
		end

	end

	#Parse
	class Parser 

		#Init
		def initialize(exception, request, controller)
			@exception, @request, @controller = exception, request, controller
		end

		#Save
		def save
			ActiveRecord::Base.logger.silence do
				ExceptionHandler::Error.create(relevant_info)
			end
 			log(relevant_info)
		end

		#Info
		def relevant_info(info = {})
			info[:class_name] 	= @exception.class.to_s
			info[:message] 		= @exception.to_s
			info[:trace] 		= @exception.backtrace.join("\n")
			info[:target_url] 	= @request.url
			info[:referer_url] 	= @request.referer
			info[:params] 		= @request.params.inspect
			info[:user_agent] 	= @request.user_agent
			if user
				info[:usable_type] 	= user[:type]
				info[:usable_id] 	= user[:id]
			end
			return info
		end

		#User
		def user(data = {})
			# => refer to Joe's if want to find admin / user
			if(@controller.respond_to?("current_user"))
				user = @controller.send("current_user")
				[:id].each do |field|
					data[:id] = user.send(field) 	if user.respond_to?(field)
					data[:type] = "user" 			if @controller.respond_to?("current_user")
				end
			end
			return data
		end

		#Log
		def log(info)
			message = "#{info[:class_name]} (#{info[:message]}):\n "
			message += Rails.backtrace_cleaner.clean(info[:trace].split("\n")).join("\n")
			Rails.logger.fatal(message)
		end

	end
end