#! /bin/env python3
# encoding: utf-8

import time
import sys

#from . import ag
#from . import gl
#from . import et
#from . import scn
#from . import ui
#from . import cmd
#from . import com
#from . import loop
from . import core

class ProgressBar:
	def __init__(self, width, total=1.0, unit="", prefix=None, suffix=None, show_percent=True, show_absolute=True, show_rate=True, show_etc=True, draw_on_update=True):
		self.width = width
		self.total = total
		self.unit = unit
		self.prefix = prefix
		self.suffix = suffix
		self.show_percent = show_percent
		self.show_absolute = show_absolute
		self.show_rate = show_rate
		self.show_etc = show_etc
		self.draw_on_update = draw_on_update
		
		self.percentage_printf = "%5.1f %%"
		self.absolute_printf_total = "%d/%d %s,"
		self.absolute_printf = "%d %s,"
		self.rate_printf_total = "%d %s/s,"
		self.rate_printf = "%d %s/s"
		self.etc_printf = "ETA %d s"
		
		self._current = 0.0
		self._ratio = 0.0
		self._rate = 0.0
		self._runner = 0.0
		
		self._start = None
		
		self._longest_line = 0
	
	@property
	def current(self):
		return self._current
	
	@current.setter
	def current(self, value):
		self._current = value
		
		self.update()
		
		if self.draw_on_update:
			self.draw()
	
	def update(self):
		if self._start is None:
			self._start = time.time()
		
		dt = (time.time() - self._start)
		
		if dt > 0:
			self._rate = self._current / dt
		else:
			self._rate = 0
		
		if self.total is None:
			self._ratio = None
			self._etc = None
			self._runner = (self._runner + 0.01) % 1.0
			
		else:
			self._ratio = self._current / self.total
			self._etc = dt * (1 / self._ratio - 1)
	
	def draw(self, overdraw=0):
		output = []
		
		if self.prefix:
			output.append(self.prefix)
		
		if self.show_percent and self.total is not None:
			output.append(self.percentage_printf %(self._ratio * 100))
		
		if self.total is None:
			count_full = int(self._runner * (self.width - 5))
			count_empty = self.width - count_full - 5
			
			output.append("[%s<=>%s]" %(" " * count_full, " " * count_empty))
		else:
			count_full = int(self._ratio * (self.width - 3))
			count_empty = self.width - count_full - 3
			
			output.append("[%s>%s]" %("=" * count_full, " " * count_empty))
		
		if self.show_absolute:
			if self.total is None:
				output.append(self.absolute_printf %(self._current, self.unit)) # TODO et.Unit
			else:
				output.append(self.absolute_printf_total %(self._current, self.total, self.unit))
		
		if self.show_rate:
			if self.total is None:
				output.append(self.rate_printf %(self._rate, self.unit))
			else:
				output.append(self.rate_printf_total %(self._rate, self.unit))
		
		if self.show_etc and self.total is not None:
			output.append(self.etc_printf %(self._etc))
		
		if self.suffix:
			output.append(self.suffix)
		
		line = " ".join(output)
		line_len = len(line)
		
		if line_len > self._longest_line:
			self._longest_line = line_len
		
		sys.stdout.write("\r%s\r" %(" " * (self._longest_line + overdraw)))
		sys.stdout.write(line)
		sys.stdout.flush()
	
	def finish(self):
		if self.total is not None:
			self.current = self.total
		
		if not self.draw_on_update:
			self.draw(overdraw=2)
		
		sys.stdout.write("\n")
		sys.stdout.flush()
	
	def __enter__(self):
		return self
	
	def __exit__(self, type, value, traceback):
		pass