Added json as possible output format for frontmatter. Added also option to...

_print = print	# save the original print function

from typing import Tuple, Generator

from typing import Tuple, Generator, Type, Iterable

import argparse

from rich import markdown, print

import re, sys, yaml, os

import re, sys, yaml, os, json

from contextlib import contextmanager

import yaml

_frontMatter:dict = {}

	_includeStack.pop()

#

# Meta class to create a YAML loader that does not resolve certain tags,

# e.g., timestamps. This is a bit of a hack since it changes the YAML loader

# after it has been created by removing the tagged resolvers.

#

# This is taken from https://stackoverflow.com/a/74695433

#

class YamlLimitedSafeLoader(type):

	"""	Meta YAML loader that skips the resolution of the specified YAML tags.

		This metaclass is the basis for creating our own YAML loaders with limited tag resolution.

	"""

	def __new__(

		cls, name, bases, namespace, do_not_resolve: Iterable[str]

	) -> Type[yaml.SafeLoader]:

		do_not_resolve = set(do_not_resolve)

		implicit_resolvers = {

			key: [(tag, regex) for tag, regex in mappings if tag not in do_not_resolve]

			for key, mappings in yaml.SafeLoader.yaml_implicit_resolvers.items()

		}

		return super().__new__(

			cls,

			name,

			(yaml.SafeLoader, *bases),

			{**namespace, "yaml_implicit_resolvers": implicit_resolvers},

		)

class YamlNoTimestampSafeLoader(metaclass=YamlLimitedSafeLoader, 

								do_not_resolve={"tag:yaml.org,2002:timestamp"}):

	"""	A safe YAML loader that leaves timestamps as strings.

		Note: 

			Extend this class to add support for additional tags by adding them to the `do_not_resolve` set.

			See "yaml.constructor" for more tags.

	"""

	pass

def expandPaths(lines:list[str], currentPath:str, childPath:str) -> list[str]:

	"""	Expand the paths in the markdown file. This means that all paths in links,

		images, and include statements are extended so that they would be valid paths

	for line in lines[1:]:

		if re.match(r'^---\s*', line):

			break

		frontMatterLines.append(line)

		frontMatterLines.append(line)	# Includes trailing newline

	# Remove the front matter from the lines

	lines = lines[len(frontMatterLines)+2:]

	# Parse the front matter as YAML

	try:

		return yaml.safe_load(''.join(frontMatterLines)), lines

		# return yaml.safe_load(''.join(frontMatterLines)), lines

		return yaml.load(''.join(frontMatterLines), YamlNoTimestampSafeLoader), lines

	except yaml.YAMLError as e:

		print(f'[red]Error parsing front matter: {e}')

		raise

	parser.add_argument('--render-markdown', '-md', dest='renderAsMarkdown', action='store_true',  help='render output as markdown')

	parser.add_argument('--process-frontmatter', '-fm', dest='outputFrontMatter', action='store_true',  help='output front matter only')

	parser.add_argument('--frontmatter-only', '-fmo', dest='onlyFrontMatter', action='store_true',  help='output only front matter')

	parser.add_argument('--frontmatter-out-file', '-fmf', dest='frontMatterOutFile', type=str, help='output front matter to a file')

	parser.add_argument('--frontmatter-out-format', '-fmt', dest='frontMatterOutFormat', type=str, choices=['yaml', 'json'], default='yaml', help='front matter output format (default: yaml)')

	parser.add_argument('--verbose', '-v', action='store_true', help='print debug information to stderr.')

	parser.add_argument('document', type=str, help='a markdown specification document to process')

	args = parser.parse_args()

	if args.outputFrontMatter or args.onlyFrontMatter:

		# Collect front matter information in the output

		if not args.onlyFrontMatter:

		if not args.onlyFrontMatter and not args.frontMatterOutFile:

			print('---')

		# The following is a workaround to keep the order of the dictionary

		# see https://stackoverflow.com/a/52621703

		yaml.add_representer(dict, lambda self, data: yaml.representer.SafeRepresenter.represent_dict(self, data.items()))

		# get output format and output file

		match args.frontMatterOutFormat:

			case 'json':

				if args.frontMatterOutFile:

					if args.verbose:

						print(f'[green]Writing front matter as JSON to {args.frontMatterOutFile}', file=sys.stderr)

					with open(args.frontMatterOutFile, 'w') as f:

						json.dump(_frontMatter, f, indent=2)

				else:

					print(json.dumps(_frontMatter, indent=2))

			case 'yaml':

				if args.frontMatterOutFile:

					if args.verbose:

						print(f'[green]Writing front matter as YAML to {args.frontMatterOutFile}', file=sys.stderr)

					with open(args.frontMatterOutFile, 'w') as f:

						f.write(yaml.dump(_frontMatter, default_flow_style=False))

				else:

					print(yaml.dump(_frontMatter, default_flow_style=False), end='')

		if not args.onlyFrontMatter:

		if not args.onlyFrontMatter and not args.frontMatterOutFile:

			print('---')

	if not args.onlyFrontMatter: