require 'webrick'
require 'webrick/https'
require 'usagewatch'

module KL
	def KL.create_default_config(file, logger)
		File.open(file, File::RDWR|File::CREAT, 0644) { |f|
			f.flock(File::LOCK_EX)
			value = '{"api":{"port":3344,"ssl":false},"notifier":{"server":"https://hub.kytoonlabs.com:4444","rate":120}}'
			f.rewind
			f.write(value.to_s)
			f.flush
			f.truncate(f.pos)
		}
		logger.info "[config] Default config file has been created at {#{file}}" if logger
	end

	def KL.logger
		home = KL.home
		Dir.mkdir(home, 0700) if not File.exist?(home)
		logFile = "#{home}/kldockeragent.log"
		log = WEBrick::Log.new(logFile, WEBrick::BasicLog::INFO ||
		                                     WEBrick::BasicLog::ERROR ||
		                                     WEBrick::BasicLog::FATAL ||
		                                     WEBrick::BasicLog::WARN)
		log
	end

	def KL.home
		home = ((Process.euid == 0 and File.directory?('/var')) ? '/var/kldockerpagent' : File.expand_path(Dir.home + '/.kldockeragent'))
		home
	end

	def KL.config
		configFile = "#{KL.home}/kldockeragent.json"
		KL.create_default_config(configFile, KL.logger) if !File.exist?(configFile)
	    config_json = File.read(configFile)
	    config_data = JSON.parse(config_json)
	    config_data
	end

	def KL.server_registered
		registryFile = "#{KL.home}/kldockeragent.registry"
		reg = File.exist?(registryFile)
		reg
	end

	def KL.publish_json(json_object, st = 200)
		status st
		content_type :json
		json_object.to_json   
	end
	def KL.prepare_agent_register_data(hash)
		data = {
			private_hash: hash,
			hostname: `hostname`.gsub("\n",""),
			system_info: `uname -a`.gsub("\n",""),
			docker_version: `docker --version`.gsub("\n","").gsub("Docker version ",""),
			agent_version: KL::Agent.getVersion,
			ip_address: IPSocket.getaddress(Socket.gethostname) 
		}
		data
	end

	def KL.create_registry_file(data)
		file = "#{KL.home}/kldockeragent.registry"
		File.open(file, File::RDWR|File::CREAT, 0644) { |f|
			f.flock(File::LOCK_EX)
			f.rewind
			f.write(data.to_json.to_s)
			f.flush
			f.truncate(f.pos)
		}
		logger.info "[config] Registry config file has been created at {#{file}}" if logger
	end

	def KL.getRegistryData
		json_reg = JSON.parse(File.open("#{KL.home}/kldockeragent.registry").read)
		json_reg
	end

	def KL.getApplicationId
		if (KL.server_registered)
			registry = KL.getRegistryData
			id = registry['agent']
		else
			id = SecureRandom.uuid
		end
		id
	end

	def KL.getAuthorizationHeaders(url, json_data)
		headers = {}
		if (KL.server_registered)
			registry = KL.getRegistryData
			hash_data = KL.generateHash(url, json_data, registry['agent'])
			auth_code = "#{registry['server']}:#{hash_data}"
			headers = {}
			headers['Authorization'] = auth_code
		end
		headers
	end

	def KL.generateHash(url, json_data, private_key)
		data = "#{url}#{json_data}"
		hash_data = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), private_key, data)
		hash_data 
	end

	def KL.prepare_agent_data
		data = {
			system_info: KL.Request_getSystemInfo,
			docker_info: KL.Request_getDockerListAllApplications,
			agent_version: KL::Agent.getVersion
		}
		data

	end

	def KL.Request_getDockerListAllApplications
		filter = '_klac'
		apps = Array.new
	    query = `docker ps --filter="name=#{filter}" --format="{{.ID}}::{{.Names}}::{{.Status}}::{{.Image}}"`
	    query.gsub!(/\r\n?/, "\n")
	    query.each_line do |line|
	        data = line.split('::')
	        apps.push({
	        	'id' => data[0], 
	        	'name' => data[1].gsub(filter,""),
	        	'status'=>data[2],
	        	'image'=>data[3].gsub("\n","")
	        	})
	    end
	    return apps
	end

	def KL.Request_getSystemInfo
		usw = Usagewatch
		info = {}
		if KL::Agent.is_linux
			info['os'] = 'linux'
			info['diskused'] = usw.uw_diskused
			info['diskused_perc'] = usw.uw_diskused_perc
			info['cpuused'] = usw.uw_cpuused
			info['memused'] = usw.uw_memused
			info['cputop'] = usw.uw_cputop
			info['memtop'] = usw.uw_memtop
		else
			info['os'] = 'not linux'
		end 
		info
	end

end