#!/usr/bin/env python3

import sys
import re
from markdown import markdown
import strictyaml
from ipo import read, write, map, dictmap, starstarmap, join, sort, ipo


md_to_html = join("\n") | ipo(markdown)
yaml_to_dict = join("\n") | ipo(strictyaml.load) | ipo(lambda x: x.data)


@ipo
def parted(data, regex):
	"""
	Two parts of data, delimited by the first element on which regex fullmatches.

	If a delimiter is found, the second part is an iterator over the remaining elements. Else it is None.
	"""
	first = []

	it = iter(data)
	try:
		while True:
			item = next(it)
			if re.fullmatch(regex, item):
				break
			first.append(item)
	except StopIteration:
		return (first, None)

	return (first, it)


LIST_ITEM_TEMPLATE = """
				<li><a href="{path}">
					<div class="title">{title}</div>
					<div class="summary">{summary}</div>
				</a></li>"""


def blog_page_template():
	with open("templates/blog.html") as fh:
		return fh.read()


# FIXME what a mess
def blog_page(file, read_body=True):
	"""
	Keep the file open if you want to be able to read the body.
	Good:
	>>> with open(…) as file:
	>>> 	metadata, body = blog_page(file)
	>>> 	[smthng(line) for line in body]
	>>> print("\n".join(hello))

	Bad:
	>>> with open(…) as file:
	>>> 	metadata, body = blog_page(file)
	>>> 	hello = (smthng(line) for line in body) # Lazy generator, the body wasn't read from file yet
	>>> print("\n".join(hello))
	"""
	if isinstance(file, str):
		assert not read_body, "Can't read body when giving a filename, need a file for that."
		filename = file
		file = open(filename)
	else:
		filename = None

	try:
		metadata_yaml, body_md = read(file) | parted("---+")

		metadata = {
			**(metadata_yaml | yaml_to_dict),
		}
		if not read_body:
			metadata["path"] = re.sub(r".md$", "", filename)

		body = (
			body_md | md_to_html(extensions=["abbr", "toc", "smarty", "fenced_code", "codehilite"])
			if read_body else None
		)

		return (metadata, body)

	finally:
		if filename:
			file.close()


def safe_metadata(metadata):
	return {
		k: (
			v
			if k in ("published", "path")
			else markdown(v, extensions=["smarty"]).replace("<p>", "").replace("</p>", "")
		)
		for k, v in metadata.items()
	}


if sys.argv[1] == "--index":
	blog_post_list = (
		sys.argv[4:] |
		map(lambda filename: {
			**blog_page(filename, read_body=False)[0],
		}) |
		sort(key=lambda x: x["published"]) |
		map(safe_metadata) |
		map(lambda metadata: LIST_ITEM_TEMPLATE.format(**metadata)) |
		join("")
	)

	with open(sys.argv[2]) as file_in, open(sys.argv[3], "w") as file_out:
		file_in.read().format(blog_posts=blog_post_list) | write(file=file_out)
else:
	with open(sys.argv[1]) as file_in, open(sys.argv[2], "w") as file_out:
		metadata, body = blog_page(file_in)
		blog_page_template().format(**safe_metadata(metadata), body=body) | write(file=file_out)