from django import template
from django.template.defaultfilters import stringfilter
from django.utils.safestring import mark_safe
import string
import re

register = template.Library()

@stringfilter
@register.filter(name='jumptime')
def jumptime(text):
	'''
	Finds timecodes in a chunk of text and turns them into links with value attribute set to where the second of the spot to jump
	Returned links also have a class of "jumpToTime" set
	'''
	# our regular expression to find times
	r = re.compile('((\d{1,2}:)?\d{1,3}:\d{2})',re.DOTALL)
	offset = 0  #used to caclulate how much text we're adding
	
	for m in re.finditer(r,text):
		timecode =  m.group(1)
		tc = timecode.split(':')
		if len(tc) == 2:
			seconds = int(tc[1]) + (int(tc[0]) * 60)
		elif len(tc) == 3:
			seconds = int(tc[2]) + (int(tc[1]) * 60) + (int(tc[0]) * 60 * 60)
		else:
			seconds = 0	
	
		if seconds != 0:
			# replaces the text at the exact position it needs to be replaced, keeps track of offset
			newText = "<a href='#' value='%s' class='jumpToTime'>%s</a>" % (seconds, timecode)	
			start = m.start() + offset
			end = m.end() + offset
			text = text[:start] + newText + text[end:]
			offset += len(newText) - len(timecode)

	return mark_safe(text)