import pygame
import collections

class GameTimer(object):
	def __init__(self):
		self.update_fps_count = None
		
	def start_loop(self):
		self.elapsed = 0
		self.elapsed_sec = 0.0
		self.timer = pygame.time.get_ticks()
		self.reset_fps_count()
		
	def next_frame(self, skipping=False):

		newticks = pygame.time.get_ticks()
		#if skipping:
		#	# reset self.timer to it's value from the previous frame
		#	self.timer -= self.elapsed
		self.elapsed = newticks - self.timer
		self.timer = newticks
		self.elapsed_sec = float(self.elapsed) / 1000.0

		if self.elapsed != 0:
			self.update_fps_count(self.elapsed)
		
		
	def reset_fps_count(self):
		self.framelist = collections.deque()
		self.update_fps_count = self.update_fps_count_empty
		
	def update_fps_count_empty(self, elapsed):
		self.framelist.append(elapsed)
		if len(self.framelist) >= 25:
			self.update_fps_count = self.update_fps_count_full
		
	def update_fps_count_full(self, elapsed):
		self.framelist.popleft()
		self.framelist.append(elapsed)
		
		
	def elapsed(self):
		"""
		get the amount of time in milliseconds passed since the last frame was displayed
		"""
		return self.elapsed
		
	def elapsed_sec(self):
		"""
		get the amount of time in seconds passed since the last frame was displayed
		"""
		return self.elapsed_sec

	def num_frames(self, delay, offset=0):
		"""
		if you want something to occur every "delay" milliseconds,
		this will return the number of times you should make it happen
		in this particular frame (can be 0)
		"""
		return int((self.timer - offset) / delay) - int((self.timer - self.elapsed - offset) / delay)

	def loop_frames(self, delay, offset=0):
		return range(num_frames(delay, offset))

	def get_timer(self):
		return self.timer

	def average(self, d):
		#spf = (float(sum(self.framelist)) / (len(self.framelist) * 1000.0))
		if len(d) == 0:
			return 0.0

		smooth = 0.85
		#v2 = float(d[-1])
		#for i in xrange(len(d) - 2, 0, -1):
		#	pass
			
		v2 = float(d[0])
		for i in range(1, len(d)):
			v1 = float(d[i])
			v2 = (smooth * v2) + ((1.0 - smooth) * v1)
		
		return v2
		
		
	def get_fps(self):
		#return ",".join([str(x) for x in sorted(self.framelist)])
		if len(self.framelist) == 0.0:
			return 0.0
		spf = self.average(self.framelist) / 1000.0
		if spf == 0.0:
			return 0.0
		#print "%s < %s" % (1.0 / spf, self.framelist)
		return 1.0 / spf