# Progress meter library for Python.
# Adam Sampson <ats@offog.org>

import sys, time

def format_time(secs):
	if secs is None:
		return "--:--:--"
	else:
		h = secs / (60 * 60)
		secs = secs % (60 * 60)
		m = secs / 60
		secs = secs % 60
		return "%02d:%02d:%02d" % (h, m, secs)

class Progress:
	def __init__(self, total, name):
		self.total = total
		self.name = name
		self.last_value = None
		self.last_time = None
		self.start_time = None
		self.closed = True
		self.log = []
		self.last_line = None

	def update(self, value):
		self.closed = False
		now = time.time()

		if self.start_time is None:
			self.start_time = now
		elapsed = now - self.start_time

		if self.log == [] or (now - self.log[-1][1]) >= 1.0:
			self.log.append((value, now))
			self.log = self.log[-4:]
		if self.log != []:
			(fv, ft) = self.log[0]
			(lv, lt) = self.log[-1]
			if (lt - ft) == 0:
				eta = None
			else:
				rate = (lv - fv) / (lt - ft)
				eta = int((self.total - value) / rate)
		else:
			eta = None

		s = "  %-40s  %3d%%  %s  %s\r" % (self.name[:60], int(100.0 * value / self.total), format_time(elapsed), format_time(eta))
		if s != self.last_line:
			sys.stderr.write(s)
			sys.stderr.flush()
			self.last_line = s

	def close(self):
		if self.closed:
			return
		self.closed = True
		if self.last_line is not None:
			sys.stderr.write("\n")
			sys.stderr.flush()