class PhusionPassenger::AnalyticsLogger::Log

def begin_measure(name, extra_info = nil)
	if extra_info
		extra_info_base64 = [extra_info].pack("m")
		extra_info_base64.gsub!("\n", "")
		extra_info_base64.strip!
	else
		extra_info_base64 = nil
	end
	times = NativeSupport.process_times
	message "BEGIN: #{name} (#{current_timestamp.to_s(36)},#{times.utime.to_s(36)},#{times.stime.to_s(36)}) #{extra_info_base64}"
end

def close(flush_to_disk = false)
	@connection.synchronize do
		return if !@connection.connected?
		begin
			# We need an ACK here. See abstract_request_handler.rb finalize_request.
			@connection.channel.write("closeTransaction", @txn_id,
				AnalyticsLogger.timestamp_string, true)
			result = @connection.channel.read
			if result != ["ok"]
				raise "Expected logging agent to respond with 'ok', but got #{result.inspect} instead"
			end
			if flush_to_disk
				@connection.channel.write("flush")
				result = @connection.channel.read
				if result != ["ok"]
					raise "Invalid logging agent response #{result.inspect} to the 'flush' command"
				end
			end
		rescue SystemCallError, IOError => e
			@connection.disconnect
			DebugLogging.warn("Error communicating with the logging agent: #{e.message}")
		rescue Exception => e
			@connection.disconnect
			raise e
		ensure
			@connection.unref
			@connection = nil
		end
	end if @connection
end

def closed?
	if @connection
		@connection.synchronize do
			return !@connection.connected?
		end
	else
		return nil
	end
end

def current_timestamp
	time = AnalyticsLogger.current_time
	return time.to_i * 1_000_000 + time.usec
end

def end_measure(name, error_encountered = false)
	times = NativeSupport.process_times
	if error_encountered
		message "FAIL: #{name} (#{current_timestamp.to_s(36)},#{times.utime.to_s(36)},#{times.stime.to_s(36)})"
	else
		message "END: #{name} (#{current_timestamp.to_s(36)},#{times.utime.to_s(36)},#{times.stime.to_s(36)})"
	end
end

def initialize(connection = nil, txn_id = nil)
	if connection
		@connection = connection
		@txn_id = txn_id
		connection.ref
	end
end

def measure(name, extra_info = nil)
	begin_measure(name, extra_info)
	begin
		yield
	rescue Exception
		error = true
		is_closed = closed?
		raise
	ensure
		end_measure(name, error) if !is_closed
	end
end

def measured_time_points(name, begin_time, end_time, extra_info = nil)
	if extra_info
		extra_info_base64 = [extra_info].pack("m")
		extra_info_base64.gsub!("\n", "")
		extra_info_base64.strip!
	else
		extra_info_base64 = nil
	end
	begin_timestamp = begin_time.to_i * 1_000_000 + begin_time.usec
	end_timestamp = end_time.to_i * 1_000_000 + end_time.usec
	message "BEGIN: #{name} (#{begin_timestamp.to_s(36)}) #{extra_info_base64}"
	message "END: #{name} (#{end_timestamp.to_s(36)})"
end

def message(text)
	if !@connection
		timestamp_string = AnalyticsLogger.timestamp_string
		DebugLogging.trace(3, "[Union Station log to null] #{@txn_id} #{timestamp_string} #{text}")
		return
	end
	@connection.synchronize do
		return if !@connection.connected?
		begin
			timestamp_string = AnalyticsLogger.timestamp_string
			DebugLogging.trace(3, "[Union Station log] #{@txn_id} #{timestamp_string} #{text}")
			@connection.channel.write("log", @txn_id, timestamp_string)
			@connection.channel.write_scalar(text)
		rescue SystemCallError, IOError => e
			@connection.disconnect
			DebugLogging.warn("Error communicating with the logging agent: #{e.message}")
		rescue Exception => e
			@connection.disconnect
			raise e
		end
	end
end

def null?
	return !@connection
end