# -*- coding: utf-8 -*-

import re
from collections import namedtuple

DomMatch = namedtuple('DOMMatch', ['attrs', 'content'])
re_type = type(re.compile(''))


def __get_dom_content(html, name, match):
	if match.endswith('/>'):
		return ''

	# override tag name with tag from match if possible
	tag = re.match('<([^\s/>]+)', match)
	if tag:
		name = tag.group(1)

	start_str = '<%s' % name
	end_str = "</%s" % name

	# start/end tags without matching case cause issues
	start = html.find(match)
	end = html.find(end_str, start)
	pos = html.find(start_str, start + 1)

	while pos < end and pos != -1:  # Ignore too early </endstr> return
		tend = html.find(end_str, end + len(end_str))
		if tend != -1:
			end = tend
		pos = html.find(start_str, pos + 1)

	if start == -1 and end == -1:
		result = ''
	elif start > -1 and end > -1:
		result = html[start + len(match):end]
	elif end > -1:
		result = html[:end]
	elif start > -1:
		result = html[start + len(match):]
	else:
		result = ''
	return result


def __get_dom_elements(item, name, attrs):
	if not attrs:
		pattern = '(<%s(?:\s[^>]*>|/?>))' % name
		this_list = re.findall(pattern, item, re.M | re.S | re.I)
	else:
		last_list = None

		for key, value in attrs.iteritems():
			value_is_regex = isinstance(value, re_type)
			value_is_str = isinstance(value, basestring)
			pattern = '''(<{tag}[^>]*\s{key}=(?P<delim>['"])(.*?)(?P=delim)[^>]*>)'''.format(tag=name, key=key)
			re_list = re.findall(pattern, item, re.M | re.S | re.I)

			if value_is_regex:
				this_list = [r[0] for r in re_list if re.match(value, r[2])]
			else:
				temp_value = [value] if value_is_str else value
				this_list = [r[0] for r in re_list if set(temp_value) <= set(r[2].split(' '))]

			if not this_list:
				has_space = (value_is_regex and ' ' in value.pattern) or (value_is_str and ' ' in value)
				if not has_space:
					pattern = '''(<{tag}[^>]*\s{key}=((?:[^\s>]|/>)*)[^>]*>)'''.format(tag=name, key=key)
					re_list = re.findall(pattern, item, re.M | re.S | re.I)
					if value_is_regex:
						this_list = [r[0] for r in re_list if re.match(value, r[1])]
					else:
						this_list = [r[0] for r in re_list if value == r[1]]

			if last_list is None:
				last_list = this_list
			else:
				last_list = [item for item in this_list if item in last_list]
		this_list = last_list
	return this_list


def __get_attribs(element):
	attribs = {}
	for match in re.finditer('''\s+(?P<key>[^=]+)=\s*(?:(?P<delim>["'])(?P<value1>.*?)(?P=delim)|(?P<value2>[^"'][^>\s]*))''', element):
		match = match.groupdict()
		value1 = match.get('value1')
		value2 = match.get('value2')
		value = value1 if value1 is not None else value2
		if value is None:
			continue
		attribs[match['key'].lower().strip()] = value
	return attribs


def parse_dom(html, name='', attrs=None, req=False, exclude_comments=False):
	if attrs is None:
		attrs = {}
	name = name.strip()

	if isinstance(html, unicode) or isinstance(html, DomMatch):
		html = [html]
	elif isinstance(html, str):
		try:
			html = [html.decode("utf-8")]  # Replace with chardet thingy
		except:
			try:
				html = [html.decode("utf-8", "replace")]
			except:
				html = [html]

	elif not isinstance(html, list):
		return ''

	if not name:
		return ''

	if not isinstance(attrs, dict):
		return ''

	if req:
		if not isinstance(req, list):
			req = [req]
		req = set([key.lower() for key in req])

	all_results = []
	for item in html:
		if isinstance(item, DomMatch):
			item = item.content

		if exclude_comments:
			item = re.sub(re.compile('<!--.*?-->', re.DOTALL), '', item)

		results = []
		for element in __get_dom_elements(item, name, attrs):
			attribs = __get_attribs(element)
			if req and not req <= set(attribs.keys()):
				continue
			temp = __get_dom_content(item, name, element).strip()
			results.append(DomMatch(attribs, temp))
			item = item[item.find(temp, item.find(element)):]
		all_results += results
	return all_results
