# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt

from __future__ import unicode_literals
import webnotes, re

def scrub_relative_urls(html):
	"""prepend a slash before a relative url"""
	return re.sub("""(src|href)[^\w'"]*['"](?!http|ftp|/|#)([^'" >]+)['"]""", '\g<1> = "/\g<2>"', html)

def can_cache(no_cache=False):
	return not (webnotes.conf.disable_website_cache or no_cache)

def get_home_page():
	home_page = webnotes.cache().get_value("home_page", \
		lambda:  (webnotes.get_hooks("home_page") \
			or [webnotes.conn.get_value("Website Settings", None, "home_page") \
			or "login"])[0])

	return home_page
			
def is_signup_enabled():
	if getattr(webnotes.local, "is_signup_enabled", None) is None:
		webnotes.local.is_signup_enabled = True
		if webnotes.utils.cint(webnotes.conn.get_value("Website Settings", 
			"Website Settings", "disable_signup")):
				webnotes.local.is_signup_enabled = False
		
	return webnotes.local.is_signup_enabled
				
def cleanup_page_name(title):
	"""make page name from title"""
	name = title.lower()
	name = re.sub('[~!@#$%^&*+()<>,."\'\?]', '', name)
	name = re.sub('[:/]', '-', name)

	name = '-'.join(name.split())

	# replace repeating hyphens
	name = re.sub(r"(-)\1+", r"\1", name)
	
	return name

def get_hex_shade(color, percent):
	def p(c):
		v = int(c, 16) + int(int('ff', 16) * (float(percent)/100))
		if v < 0: 
			v=0
		if v > 255: 
			v=255
		h = hex(v)[2:]
		if len(h) < 2:
			h = "0" + h
		return h
		
	r, g, b = color[0:2], color[2:4], color[4:6]
	
	avg = (float(int(r, 16) + int(g, 16) + int(b, 16)) / 3)
	# switch dark and light shades
	if avg > 128:
		percent = -percent

	# stronger diff for darker shades
	if percent < 25 and avg < 64:
		percent = percent * 2
	
	return p(r) + p(g) + p(b)