#    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 re

import mistletoe

mistletoe.block_token.remove_token(mistletoe.block_token.BlockCode)

class Heading(mistletoe.block_token.BlockToken):
	pattern = re.compile(r'(#{1,6})\s*([0-9A-Z]+)\s+(.+)')
	
	def __init__(self, match):
		self.level, self.label, content = match
		self.children = mistletoe.span_token.tokenize_inner(content)
	
	@classmethod
	def start(cls, line):
		return cls.pattern.match(line)
	
	@classmethod
	def read(cls, lines):
		line = next(lines)
		match = cls.pattern.match(line)
		
		level = len(match.group(1))
		label = match.group(2)
		content = match.group(3)
		
		if content == '***':
			content = '★★★'
		
		return level, label, content

mistletoe.block_token.remove_token(mistletoe.block_token.Heading)
mistletoe.block_token.add_token(Heading)

class Subrules(mistletoe.block_token.BlockToken):
	pattern = re.compile(r'\t*\(([0-9A-Za-z–]+)\)\s+.')
	
	def __init__(self, children):
		self.children = children
	
	@classmethod
	def start(cls, line):
		return cls.pattern.match(line)
	
	@classmethod
	def read(cls, lines):
		children = []
		while True:
			lines.anchor()
			try:
				line = next(lines)
			except StopIteration:
				break
			
			if len(line.strip()) == 0:
				continue
			
			lines.reset()
			
			if not SubrulesItem.start(line):
				break
			
			children.append(SubrulesItem(*SubrulesItem.read(lines)))
		
		return children

mistletoe.block_token.add_token(Subrules)

class SubrulesItem(mistletoe.block_token.BlockToken):
	pattern = re.compile(r'(\t*)(\([0-9A-Za-z–]+\))?\s*(.+)')
	
	def __init__(self, level, label, children):
		self.level = level
		self.label = label
		self.children = children
	
	@classmethod
	def start(cls, line):
		match = cls.pattern.match(line)
		if not match.group(1) and not match.group(2):
			# Neither an indent nor a label
			return False
		return True
	
	@classmethod
	def read(cls, lines):
		line = next(lines)
		lead_in, label, content = cls.pattern.match(line).group(1, 2, 3)
		
		if content == '***':
			content = '★★★'
		
		level = len(lead_in)
		children = mistletoe.span_token.tokenize_inner(content)
		
		if label is None:
			level -= 1
		
		return level, label, children

class Note(mistletoe.block_token.BlockToken):
	pattern = re.compile(r'([0-9A-Z ]+):\s+(.+)')
	
	def __init__(self, match):
		self.label, content = match
		self.children = mistletoe.span_token.tokenize_inner(content)
	
	@classmethod
	def start(cls, line):
		return cls.pattern.match(line)
	
	@classmethod
	def read(cls, lines):
		line = next(lines)
		match = cls.pattern.match(line)
		
		label, content = match.group(1, 2)
		label = label[0].upper() + label[1:].lower()
		return label, content

mistletoe.block_token.add_token(Note)

class Definition(mistletoe.block_token.BlockToken):
	pattern = re.compile(r'\*\*\*(.+)\*\*\*(:|.*means)')
	
	def __init__(self, match):
		self.children = mistletoe.span_token.tokenize_inner(match)
	
	@classmethod
	def start(cls, line):
		return cls.pattern.match(line)
	
	@classmethod
	def read(cls, lines):
		return next(lines).rstrip('\n')

mistletoe.block_token.add_token(Definition)