# This code is in the public domain, it comes
# with absolutely no warranty and you can do
# absolutely whatever you want with it.

# Figment: Edits add element_closer to elements
#          to enhance expressiveness

__date__ = '1 October 2012'
__version__ = '1.9'
__doc__ = """
This is markup.py - a Python module that attempts to
make it easier to generate HTML/XML from a Python program
in an intuitive, lightweight, customizable and pythonic way.

The code is in the public domain.

Version: %s as of %s.

Documentation and further info is at http://markup.sourceforge.net/

Please send bug reports, feature requests, enhancement
ideas or questions to nogradi at gmail dot com.

Installation: drop markup.py somewhere into your Python path.
""" % (__version__, __date__)

try:
	basestring
	import string
except:
	# python 3
	basestring = str
	string = str

# tags which are reserved python keywords will be referred
# to by a leading underscore otherwise we end up with a syntax error
import keyword

class element:
	"""This class handles the addition of a new element."""

	class empty_element_closer:
		def __init__(self, tag):
			pass
		def close(self):
			pass
		def __enter__(self):
			return self
		def __exit__(self, type, value, tb):
			pass
		def __getattr__(self, attr):
			print attr
			raise AttributeError(attr)

	class element_closer:
		def __init__(self, tag, parent):
			self.tag = tag
			self.parent = parent
		def close(self):
			elem = self.parent.__getattr__(self.tag)
			if elem: elem.close()
		def __enter__(self):
			return self
		def __exit__(self, type, value, tb):
			self.close()
		def __getattr__(self, attr):
			return self.parent.__getattr__(attr)
		def add(self, text):
			return self.parent.addcontent(text)
			
	def __init__(self, tag, case='lower', parent=None):
		self.parent = parent

		if case == 'upper':
			self.tag = tag.upper()
		elif case == 'lower':
			self.tag = tag.lower()
		elif case == 'given':
			self.tag = tag
		else:
			self.tag = tag
	
	def __call__(self, *args, **kwargs):
		if len(args) > 1:
			raise ArgumentError(self.tag)

		# if class_ was defined in parent it should be added to every element
		if self.parent is not None and self.parent.class_ is not None:
			if 'class_' not in kwargs:
				kwargs['class_'] = self.parent.class_
			
		if self.parent is None:
			if len(args) == 1:
				x = [ self.render(self.tag, False, myarg, mydict) for myarg, mydict in _argsdicts(args, kwargs) ]
				return '\n'.join(x)
			if len(args) == 0:
				x = [ self.render(self.tag, True, myarg, mydict) for myarg, mydict in _argsdicts(args, kwargs) ]
				return '\n'.join(x)
			
		if self.tag in self.parent.twotags:
			for myarg, mydict in _argsdicts(args, kwargs):
				self.render(self.tag, False, myarg, mydict)
			return element.element_closer(self.tag, self.parent)
			
		elif self.tag in self.parent.onetags:
			if len(args) == 0:
				for myarg, mydict in _argsdicts(args, kwargs):
					self.render(self.tag, True, myarg, mydict)    # here myarg is always None, because len( args ) = 0
				#return element.empty_element_closer(self.tag)
			else:
				raise ClosingError(self.tag)
		elif self.parent.mode == 'strict_html' and self.tag in self.parent.deptags:
			raise DeprecationError(self.tag)
		else:
			raise InvalidElementError(self.tag, self.parent.mode)
	
	def render(self, tag, single, between, kwargs):
		"""Append the actual tags to content."""

		out = "<%s" % tag
		for key, value in list(kwargs.items()):
			if value is not None:               # when value is None that means stuff like <...  checked>
				key = key.strip('_')            # strip this so class_ will mean class, etc.
				if key == 'http_equiv':         # special cases, maybe change _ to - overall?
					key = 'http-equiv'
				elif key == 'accept_charset':
					key = 'accept-charset'
				out = "%s %s=\"%s\"" % (out, key, escape(value))
			else:
				out = "%s %s" % (out, key)
		if between is not None:
			out = "%s>%s</%s>" % (out, between, tag)
		else:
			if single:
				out = "%s />" % out
			else:
				out = "%s>" % out
		if self.parent is not None:
			self.parent.content.append(out)
		else:
			return out
	
	def close(self):
		"""Append a closing tag unless element has only opening tag."""

		if self.tag in self.parent.twotags:
			self.parent.content.append("</%s>" % self.tag)
		elif self.tag in self.parent.onetags:
			raise ClosingError(self.tag)
		elif self.parent.mode == 'strict_html' and self.tag in self.parent.deptags:
			raise DeprecationError(self.tag)
			
	def open(self, **kwargs):
		"""Append an opening tag."""

		if self.tag in self.parent.twotags or self.tag in self.parent.onetags:
			self.render(self.tag, False, None, kwargs)
		elif self.mode == 'strict_html' and self.tag in self.parent.deptags:
			raise DeprecationError(self.tag)
			
class page:
	"""This is our main class representing a document. Elements are added
	as attributes of an instance of this class."""

	def __init__(self, mode='strict_html', case='lower', onetags=None, twotags=None, separator='\n', class_=None):
		"""Stuff that effects the whole document.

		mode -- 'strict_html'   for HTML 4.01 (default)
				'html'          alias for 'strict_html'
				'loose_html'    to allow some deprecated elements
				'xml'           to allow arbitrary elements

		case -- 'lower'         element names will be printed in lower case (default)
				'upper'         they will be printed in upper case
				'given'         element names will be printed as they are given

		onetags --              list or tuple of valid elements with opening tags only
		twotags --              list or tuple of valid elements with both opening and closing tags
								these two keyword arguments may be used to select
								the set of valid elements in 'xml' mode
								invalid elements will raise appropriate exceptions
		
		separator --            string to place between added elements, defaults to newline
		
		class_ --               a class that will be added to every element if defined"""
		
		valid_onetags = ["AREA", "BASE", "BR", "COL", "FRAME", "HR", "IMG", "INPUT", "LINK", "META", "PARAM"]
		valid_twotags = ["A", "ABBR", "ACRONYM", "ADDRESS", "B", "BDO", "BIG", "BLOCKQUOTE", "BODY", "BUTTON",
				"CAPTION", "CITE", "CODE", "COLGROUP", "DD", "DEL", "DFN", "DIV", "DL", "DT", "EM", "FIELDSET",
				"FORM", "FRAMESET", "H1", "H2", "H3", "H4", "H5", "H6", "HEAD", "HTML", "I", "IFRAME", "INS",
				"KBD", "LABEL", "LEGEND", "LI", "MAP", "NOFRAMES", "NOSCRIPT", "OBJECT", "OL", "OPTGROUP",
				"OPTION", "P", "PRE", "Q", "SAMP", "SCRIPT", "SELECT", "SMALL", "SPAN", "STRONG", "STYLE",
				"SUB", "SUP", "TABLE", "TBODY", "TD", "TEXTAREA", "TFOOT", "TH", "THEAD", "TITLE", "TR",
				"TT", "UL", "VAR"]
		deprecated_onetags = ["BASEFONT", "ISINDEX"]
		deprecated_twotags = ["APPLET", "CENTER", "DIR", "FONT", "MENU", "S", "STRIKE", "U"]

		self.header = []
		self.content = []
		self.footer = []
		self.case = case
		self.separator = separator

		# init( ) sets it to True so we know that </body></html> has to be
		# printed at the end
		self._full = False
		self.class_ = class_

		if mode == 'strict_html' or mode == 'html':
			self.onetags = valid_onetags
			self.onetags += list(map(string.lower, self.onetags))
			self.twotags = valid_twotags
			self.twotags += list(map(string.lower, self.twotags))
			self.deptags = deprecated_onetags + deprecated_twotags
			self.deptags += list(map(string.lower, self.deptags))
			self.mode = 'strict_html'
		elif mode == 'loose_html':
			self.onetags = valid_onetags + deprecated_onetags 
			self.onetags += list(map(string.lower, self.onetags))
			self.twotags = valid_twotags + deprecated_twotags
			self.twotags += list(map(string.lower, self.twotags))
			self.mode = mode
		elif mode == 'xml':
			if onetags and twotags:
				self.onetags = onetags
				self.twotags = twotags
			elif (onetags and not twotags) or (twotags and not onetags):
				raise CustomizationError()
			else:
				self.onetags = russell()
				self.twotags = russell()
			self.mode = mode
		else:
			raise ModeError(mode)

	def __getattr__(self, attr):
		# common case does not have '_'
		if not attr.startswith('_'):
			return element(attr, case=self.case, parent=self)

		# tags should start with double underscore
		if attr.startswith("__") and attr.endswith("__"):
			raise AttributeError(attr)
		
		# tag with single underscore should be a reserved keyword
		attr = attr.lstrip('_') 
		if attr not in keyword.kwlist:
			raise AttributeError(attr)
		return element(attr, case=self.case, parent=self)

	def __str__(self):
		
		if self._full and (self.mode == 'strict_html' or self.mode == 'loose_html'):
			end = ['</body>', '</html>']
		else:
			end = []

		return self.separator.join(self.header + self.content + self.footer + end)

	def __call__(self, escape=False):
		"""Return the document as a string.

		escape --   False   print normally
					True    replace < and > by &lt; and &gt;
							the default escape sequences in most browsers"""

		if escape:
			return _escape(self.__str__())
		else:
			return self.__str__()

	def add(self, text):
		"""This is an alias to addcontent."""
		self.addcontent(text)

	def addfooter(self, text):
		"""Add some text to the bottom of the document"""
		self.footer.append(text)

	def addheader(self, text):
		"""Add some text to the top of the document"""
		self.header.append(text)

	def addcontent(self, text):
		"""Add some text to the main part of the document"""
		self.content.append(text)


	def init(self, lang='en', css=None, metainfo=None, title=None, header=None,
			footer=None, charset=None, encoding=None, doctype=None, bodyattrs=None, script=None, base=None):
		"""This method is used for complete documents with appropriate
		doctype, encoding, title, etc information. For an HTML/XML snippet
		omit this method.

		lang --     language, usually a two character string, will appear
					as <html lang='en'> in html mode (ignored in xml mode)
		
		css --      Cascading Style Sheet filename as a string or a list of
					strings for multiple css files (ignored in xml mode)

		metainfo -- a dictionary in the form { 'name':'content' } to be inserted
					into meta element(s) as <meta name='name' content='content'>
					(ignored in xml mode)
		
		base     -- set the <base href="..."> tag in <head>
		
		bodyattrs --a dictionary in the form { 'key':'value', ... } which will be added
					as attributes of the <body> element as <body key='value' ... >
					(ignored in xml mode)

		script --   dictionary containing src:type pairs, <script type='text/type' src=src></script>
					or a list of [ 'src1', 'src2', ... ] in which case 'javascript' is assumed for all

		title --    the title of the document as a string to be inserted into
					a title element as <title>my title</title> (ignored in xml mode)

		header --   some text to be inserted right after the <body> element
					(ignored in xml mode)

		footer --   some text to be inserted right before the </body> element
					(ignored in xml mode)

		charset --  a string defining the character set, will be inserted into a
					<meta http-equiv='Content-Type' content='text/html; charset=myset'>
					element (ignored in xml mode)

		encoding -- a string defining the encoding, will be put into to first line of
					the document as <?xml version='1.0' encoding='myencoding' ?> in
					xml mode (ignored in html mode)

		doctype --  the document type string, defaults to
					<!DOCTYPE HTML PUBLIC '-//W3C//DTD HTML 4.01 Transitional//EN'>
					in html mode (ignored in xml mode)"""

		self._full = True

		if self.mode == 'strict_html' or self.mode == 'loose_html':
			if doctype is None:
				doctype = "<!DOCTYPE HTML PUBLIC '-//W3C//DTD HTML 4.01 Transitional//EN'>"
			self.header.append(doctype)
			self.html(lang=lang)
			self.head()
			if charset is not None:
				self.meta(http_equiv='Content-Type', content="text/html; charset=%s" % charset)
			if metainfo is not None:
				self.metainfo(metainfo)
			if css is not None:
				self.css(css)
			if title is not None:
				self.title(title)
			if script is not None:
				self.scripts(script)
			if base is not None:
				self.base(href='%s' % base)
			self.head.close()
			if bodyattrs is not None:
				self.body(**bodyattrs)
			else:
				self.body()
			if header is not None:
				self.content.append(header)
			if footer is not None:
				self.footer.append(footer)

		elif self.mode == 'xml':
			if doctype is None:
				if encoding is not None:
					doctype = "<?xml version='1.0' encoding='%s' ?>" % encoding
				else:
					doctype = "<?xml version='1.0' ?>"
			self.header.append(doctype)

	def css(self, filelist):
		"""This convenience function is only useful for html.
		It adds css stylesheet(s) to the document via the <link> element."""
	
		if isinstance(filelist, basestring):
			self.link(href=filelist, rel='stylesheet', type='text/css', media='all')
		else:
			for file in filelist:
				self.link(href=file, rel='stylesheet', type='text/css', media='all')

	def metainfo(self, mydict):
		"""This convenience function is only useful for html.
		It adds meta information via the <meta> element, the argument is
		a dictionary of the form { 'name':'content' }."""

		if isinstance(mydict, dict):
			for name, content in list(mydict.items()):
				self.meta(name=name, content=content)
		else:
			raise TypeError("Metainfo should be called with a dictionary argument of name:content pairs.")

	def scripts(self, mydict):
		"""Only useful in html, mydict is dictionary of src:type pairs or a list
		of script sources [ 'src1', 'src2', ... ] in which case 'javascript' is assumed for type.
		Will be rendered as <script type='text/type' src=src></script>"""

		if isinstance(mydict, dict):
			for src, type in list(mydict.items()):
				self.script('', src=src, type='text/%s' % type)
		else:
			try:
				for src in mydict:
					self.script('', src=src, type='text/javascript')
			except:
				raise TypeError("Script should be given a dictionary of src:type pairs or a list of javascript src's.")


class _oneliner:
	"""An instance of oneliner returns a string corresponding to one element.
	This class can be used to write 'oneliners' that return a string
	immediately so there is no need to instantiate the page class."""
	
	def __init__(self, case='lower'):
		self.case = case
	
	def __getattr__(self, attr):
		
		# tags should start with double underscore
		if attr.startswith("__") and attr.endswith("__"):
			raise AttributeError(attr)
		# tag with single underscore should be a reserved keyword
		if attr.startswith('_'):
			attr = attr.lstrip('_') 
			if attr not in keyword.kwlist:
				raise AttributeError(attr)
		
		return element(attr, case=self.case, parent=None)

oneliner = _oneliner(case = 'lower' )
upper_oneliner = _oneliner(case='upper')
given_oneliner = _oneliner(case='given')

def _argsdicts(args, mydict):
	"""A utility generator that pads argument list and dictionary values, will only be called with len( args ) = 0, 1."""
	
	if len(args) == 0:
		args = None, 
	elif len(args) == 1:
		args = _totuple(args[0])
	else:
		raise Exception("We should have never gotten here.")

	mykeys = list(mydict.keys())
	myvalues = list(map(_totuple, list(mydict.values())))

	maxlength = max(list(map(len, [args] + myvalues)))

	for i in range(maxlength):
		thisdict = { }
		for key, value in zip(mykeys, myvalues):
			try:
				thisdict[key] = value[i]
			except IndexError, e:
				print e
				thisdict[key] = value[-1]
		try:
			thisarg = args[i]
		except IndexError, e:
			print e
			thisarg = args[-1]

		yield thisarg, thisdict

def _totuple(x):
	"""Utility stuff to convert string, int, long, float, None or anything to a usable tuple."""

	if isinstance(x, basestring):
		out = x,
	elif isinstance(x, (int, long, float)):
		out = str(x),
	elif x is None:
		out = None,
	else:
		out = tuple(x)

	return out

def escape(text, newline=False):
	"""Escape special html characters."""

	if isinstance(text, basestring):
		if '&' in text:
			text = text.replace('&', '&amp;')
		if '>' in text:
			text = text.replace('>', '&gt;')
		if '<' in text:
			text = text.replace('<', '&lt;')
		if '\"' in text:
			text = text.replace('\"', '&quot;')
		if '\'' in text:
			text = text.replace('\'', '&quot;')
		if newline:
			if '\n' in text:
				text = text.replace('\n', '<br>')

	return text

_escape = escape

def unescape(text):
	"""Inverse of escape."""
	
	if isinstance(text, basestring):
		if '&amp;' in text:
			text = text.replace('&amp;', '&')
		if '&gt;' in text:
			text = text.replace('&gt;', '>')
		if '&lt;' in text:
			text = text.replace('&lt;', '<')
		if '&quot;' in text:
			text = text.replace('&quot;', '\"')

	return text

class dummy:
	"""A dummy class for attaching attributes."""
	pass

doctype = dummy()
doctype.frameset = """<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">"""
doctype.strict = """<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">"""
doctype.loose = """<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">"""

class russell:
	"""A dummy class that contains anything."""

	def __contains__(self, item):
		return True


class MarkupError(Exception):
	"""All our exceptions subclass this."""
	def __str__(self):
		return self.message

class ClosingError(MarkupError):
	def __init__(self, tag):
		self.message = "The element '%s' does not accept non-keyword arguments (has no closing tag)." % tag

class OpeningError(MarkupError):
	def __init__(self, tag):
		self.message = "The element '%s' can not be opened." % tag

class ArgumentError(MarkupError):
	def __init__(self, tag):
		self.message = "The element '%s' was called with more than one non-keyword argument." % tag

class InvalidElementError(MarkupError):
	def __init__(self, tag, mode):
		self.message = "The element '%s' is not valid for your mode '%s'." % (tag, mode)

class DeprecationError(MarkupError):
	def __init__(self, tag):
		self.message = "The element '%s' is deprecated, instantiate markup.page with mode='loose_html' to allow it." % tag

class ModeError(MarkupError):
	def __init__(self, mode):
		self.message = "Mode '%s' is invalid, possible values: strict_html, html (alias for strict_html), loose_html, xml." % mode

class CustomizationError(MarkupError):
	def __init__(self):
		self.message = "If you customize the allowed elements, you must define both types 'onetags' and 'twotags'."

if __name__ == '__main__':
	import sys
	sys.stdout.write(__doc__)
