#    legalmd: Markdown-based legal markup
#    Copyright © 2019  Lee Yingtong Li (RunasSudo)
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.

import mistletoe
import mistletoe.latex_renderer

LMARG = 1 #cm

def cm_to_twip(cms):
	return int(cms * 0.3937008 * 1440)

def format(fstr, *args, **kwargs):
	fstr2 = fstr
	fstr2 = fstr2.replace('\\N', '\n')
	fstr2 = fstr2.replace('{', '{{')
	fstr2 = fstr2.replace('}', '}}')
	fstr2 = fstr2.replace('<', '{')
	fstr2 = fstr2.replace('>', '}')
	
	kwargs['lmarg'] = cm_to_twip(LMARG)
	
	return fstr2.format(*args, **kwargs)

class RTFRenderer(mistletoe.base_renderer.BaseRenderer):
	def __init__(self, *extras):
		super().__init__(*extras)
		
		self.render_map['Subrules'] = self.render_subrules
		self.render_map['SubrulesItem'] = self.render_subrules_item
		self.render_map['Note'] = self.render_note
		self.render_map['Definition'] = self.render_definition
		
		self.lastalign = 0
		self.heading_last = False
	
	def render_strong(self, token):
		return format(r'{\b <>}', self.render_inner(token))
	
	def render_emphasis(self, token):
		return format(r'{\i <>}', self.render_inner(token))
	
	def render_inline_code(self, token):
		raise Exception('NYI')
	
	def render_raw_text(self, token):
		return token.content.replace('\\', '\\\\').replace('{', r'\{').replace('}', r'\}')
	
	def render_strikethrough(self, token):
		raise Exception('NYI')
	
	def render_image(self, token):
		raise Exception('NYI')
	
	def render_link(self, token):
		raise Exception('NYI')
	
	def render_auto_link(self, token):
		raise Exception('NYI')
	
	def render_escape_sequence(self, token):
		raise Exception('NYI')
	
	def render_heading(self, token):
		if token.level == 1:
			# Part
			heading_last, self.heading_last = self.heading_last, True
			return format(r'{\sb<space_above>\keepn\b\fs26\qc\caps Part <label>\u8212?<content>\par}',
				space_above=cm_to_twip(1),
				label=token.label,
				content=self.render_inner(token)
			)
		
		if token.level == 2:
			# Division
			heading_last, self.heading_last = self.heading_last, True
			return format(r'{\sb<space_above>\keepn\b\fs26\qc Division <label>\u8212?<content>\par}',
				space_above=cm_to_twip(1 if not heading_last else 0),
				label=token.label,
				content=self.render_inner(token)
			)
		
		if token.level == 3:
			# Section
			heading_last, self.heading_last = self.heading_last, False
			return format(r'{\keepn\b\fi-<hangindent>\li<hangindent> <label>\tab <content>\par}',
				hangindent=cm_to_twip(LMARG),
				label=token.label,
				content=self.render_inner(token)
			)
	
	def render_quote(self, token):
		raise Exception('NYI')
	
	def render_paragraph(self, token):
		self.lastalign = LMARG
		self.heading_last = False
		
		return format(r'{\li<lmarg> <content>\par}',
			content=self.render_inner(token)
		)
	
	def render_block_code(self, token):
		raise Exception('NYI')
	
	def render_block_code(self, token):
		raise Exception('NYI')
	
	def render_list(self, token):
		raise Exception('NYI')
	
	def render_list_item(self, token):
		raise Exception('NYI')
	
	def render_table(self, token):
		raise Exception('NYI')
	
	def render_table_row(self, token):
		raise Exception('NYI')
	
	def render_table_cell(self, token):
		raise Exception('NYI')
	
	def render_thematic_break(self, token):
		raise Exception('NYI')
	
	def render_line_break(self, token):
		return r'\line '
	
	def render_subrules(self, token):
		self.heading_last = False
		
		return self.render_inner(token)
	
	def render_subrules_item(self, token):
		if token.label:
			self.lastalign = LMARG + token.level + 1
			return format(r'{\fi<fi>\li<li> <label>\tab <content>\par}',
				fi=cm_to_twip(-1),
				li=cm_to_twip(LMARG + token.level + 1),
				label=token.label,
				content=self.render_inner(token)
			)
		else:
			self.lastalign = LMARG + token.level + 1
			return format(r'{\li<li> <content>\par}',
				li=cm_to_twip(LMARG + token.level + 1),
				label=token.label,
				content=self.render_inner(token)
			)
	
	def render_note(self, token):
		self.heading_last = False
		
		return format(r'{\fs20\li<lastalign>{\b <label>:} <content>\par}',
			lastalign=cm_to_twip(self.lastalign),
			label=token.label,
			content=self.render_inner(token)
		)
	
	def render_definition(self, token):
		self.lastalign = LMARG + 2
		self.heading_last = False
		
		return format(r'{\fi<fi>\li<li> <content>\par}',
			fi=cm_to_twip(-1),
			li=cm_to_twip(LMARG + 2),
			content=self.render_inner(token)
		)
	
	def render_document(self, token):
		result_str = format(r'{\rtf1\deff0{\fonttbl{\f0 TeX Gyre Heros{\*\falt FreeSans}{\*\falt Liberation Sans}{\*\falt Arial};}}\paperw<paperw>\paperh<paperh>\margl<margin>\margr<margin>\margt<margin>\margb<margin>{\header\f0\fs16\tqr\tx<flushright> <title>\tab <author>}{\footer\f0\fs16\tqr\tx<flushright> <footer>\tab\chpgn}\sa<parskip>\fs1\~\fs24 <inner>}',
			paperw=cm_to_twip(21),
			paperh=cm_to_twip(29.7),
			margin=cm_to_twip(2),
			flushright=cm_to_twip(21 - 2 - 2),
			parskip=cm_to_twip(0.35),
			inner=self.render_inner(token),
			title=token.title,
			author=token.author,
			footer=token.footer
		)
		
		result = []
		for char in result_str:
			if ord(char) <= 0x7f:
				result.append(char)
			else:
				result.append(r'\u{}?'.format(ord(char)))
		return ''.join(result)