indexing
	description: "Discovery service example"
	license: "MIT license (see ../../license.txt)"
	author: "Beat Strasser <beat@stradax.net>"
	date: "$Date$"
	revision: "$Revision$"

class
	DISCOVERY

inherit
	L4E_PRIORITY_CONSTANTS
	THREAD_CONTROL
	ARGUMENTS

create
	make

feature {NONE} -- Initialization

	make is
			-- Create discovery example client
		local
			vampeer: P2P_PLATFORM
			failed: BOOLEAN
		do
			if not failed and argument_count = 1 then
				-- create stdout logger
				create_logger

				-- create vampeer platform
				vampeer := configure_platform
				if vampeer.module_status /= vampeer.init_failed then
					-- now start platform
					vampeer.start
					if vampeer.module_status = vampeer.start_ok then
						-- wait for connection
						from
						until
							npg.rendezvous_service.is_connected
						loop
							sleep (250000000)
						end
						-- publish our peer advertisement
						npg.discovery_service.publish_advertisement_remotely (npg.peer_advertisement, Void)
						-- query for peers
						query_for_peers
						sleep (60000000000)  -- wait 1 minute
					end
				end
			elseif argument_count /= 1 then
				io.put_string ("Usage: " + argument (0) + " ConfigDirectory")
				io.new_line
			end

			-- stop platform
			if vampeer /= Void and vampeer.module_status = vampeer.start_ok then
				vampeer.stop
			end
		rescue
			failed := True
			retry
		end

feature -- Access

	logger: L4E_LOGGER
	npg: P2P_PEERGROUP

feature {NONE} -- Implementation

	create_logger is
			-- Create log hierarchy and set `logger'
		local
			log_hierarchy: L4E_HIERARCHY
			log_appender: L4E_APPENDER
			log_layout: L4E_DATE_TIME_LAYOUT
		do
			create log_hierarchy.make (info_p)
			logger := log_hierarchy.root
			create {L4E_STDOUT_APPENDER} log_appender.make ("stdoutapp")
			create log_layout
			log_appender.set_layout (log_layout)
			logger.add_appender (log_appender)
		ensure
			Logger_set: logger /= Void
		end

	configure_platform: P2P_PLATFORM is
			-- Configure platform and initialize net peer group
		local
			conf: P2P_CONFIGURATION
		do
			create Result.make (argument (1), logger)
			if not Result.is_configured then
				conf := Result.default_configuration
				conf.set_name ("discovery")
				conf.set_description ("Sends discovery query and waits for responses")
				Result.configure (conf)
			end
			if Result.is_configured then
				npg := Result.standard_net_peergroup
			end
		end

	discovery_response_handler (response: P2P_DISCOVERY_RESPONSE) is
			-- Handles discovery response for registered query
		require
			Response_valid: response /= Void and response.is_valid
		do
			if response.peer_advertisement /= Void then
				logger.info ("New discovered peer: %N" + response.peer_advertisement.out + "%N%N")
			end
			from
				response.responses.start
			until
				response.responses.after
			loop
				logger.info ("New discovered peer: %N" + response.responses.item_for_iteration.out + "%N%N")
				response.responses.forth
			end
		end

	query_for_peers is
			-- Send general peer discovery query
		local
			query: P2P_DISCOVERY_QUERY
		do
			create query.make ({P2P_DISCOVERY_SERVICE}.type_peer)
			query.set_threshold (10)
			npg.discovery_service.query_remote_advertisements (query, Void, agent discovery_response_handler)
			logger.info ("Discovery request sent.")
		end

end