class Sus::Clock

def self.start!
	self.new.tap(&:start!)
end

def <=>(other)
	duration <=> other.to_f
end

def duration
	if @start_time
		now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
		@duration += now - @start_time
		@start_time = now
	end
	
	return @duration
end

def initialize(duration = 0.0)
	@duration = duration
end

def ms
	duration * 1000.0
end

def reset!(duration = 0.0)
	@duration = duration
end

def start!
	@start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
end

def stop!
	if @start_time
		now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
		@duration += now - @start_time
		@start_time = nil
	end
	
	return duration
end

def to_f
	duration
end

def to_s
	duration = self.duration
	
	if duration < 0.001
		"#{(duration * 1_000_000).round(1)}µs"
	elsif duration < 1.0
		"#{(duration * 1_000).round(1)}ms"
	else
		"#{duration.round(1)}s"
	end
end