# -*- coding: UTF-8 -*-
#
# Desc:    This file is part of the eCromedos document preparation system
# Date:    2006/03/09
# Author:  Tobias Koch (tkoch@ecromedos.net)
# License: GNU General Public License, version 2
# URL:     http://www.ecromedos.net
#

# ecmds includes
from error import ECMDSPluginError


def getInstance(config):
	'''Returns a plugin instance.'''
	return Plugin(config)
#end function


class Plugin:

	def __init__(self, config):
		self.lstrip = False
	#end function


	def flush(self):
		pass
	#end function


	def process(self, node, format):
		'''Prepare @node for target @format.'''
		
		if format == "latex":
			string = self.LaTeX_sanitizeString(node.getContent())
			if string: node.setContent(string)
		#end if

		return node
	#end function


	def LaTeX_sanitizeString(self, string):
		'''Replace any character that could have a special
		   meaning in some context in LaTeX with a unicode macro.'''

		special_chars = "[]{}#&_%$\\~-:;!?\"`'^=\n"

		frame_start = 0
		frame_end = 0
		parts = []
		length = len(string)
		
		# lstrip if needed
		if self.lstrip:
			while frame_end < length:
				ch = string[frame_end]
				if not ch.isspace():
					self.lstrip = False
					break
				#end if
				frame_end += 1
				if ch == '\n':
					frame_start = frame_end
				#end if
			#end while
			if frame_end > frame_start:
				parts.append(string[frame_start:frame_end])
				frame_start = frame_end
			#end if
		#end if
		
		# replace special chars
		while frame_end < length:
			ch = string[frame_end]
			if ch in special_chars:
				if frame_end > frame_start:
					parts.append(string[frame_start:frame_end])
				#end if
				if ch == '\n': # cut multiple linebreaks
					if not self.lstrip:
						parts.append(ch)
						self.lstrip = True
					#end if
					frame_end += 1
					frame_start = frame_end
					while frame_end < length:
						ch = string[frame_end]
						if not ch.isspace():
							self.lstrip = False
							break
						#end if
						frame_end += 1
						if ch == '\n':
							frame_start = frame_end
						#end if
					#end while
					if frame_end > frame_start:
						parts.append(string[frame_start:frame_end])
						frame_start = frame_end
					#end if
				else:
					parts.append("{\unichar{" + str(ord(ch)) + "}}")
					frame_end += 1
					frame_start = frame_end
				#end if
			else:
				frame_end += 1
			#end if
		#end while

		if frame_start == 0: return None
		if frame_end > frame_start: parts.append(string[frame_start:frame_end])
		return "".join(parts)
	#end function

#end class