# literaly the example at https://python-markdown.github.io/extensions/api/#inlineprocessors
# but modified to use ~~text~~ instead of --text--

from markdown.inlinepatterns import InlineProcessor
from markdown.blockprocessors import BlockProcessor
from markdown import util
from markdown.extensions import Extension
import xml.etree.ElementTree as etree
import re


class DelInlineProcessor(InlineProcessor):
    def handleMatch(self, m, data):
        el = etree.Element('del')
        el.text = m.group(1)
        return el, m.start(0), m.end(0)

class DelExtension(Extension):
    def extendMarkdown(self, md):
        DEL_PATTERN = r'~~(.*?)~~'  # like ~~del~~
        md.inlinePatterns.register(DelInlineProcessor(DEL_PATTERN, md), 'del', 175)


# once again, but this time for __underlined__
# works a bit weird with italic-underlined like ___this___. use __*this*__ instead.

class UInlineProcessor(InlineProcessor):
    def handleMatch(self, m, data):
        el = etree.Element('u')
        el.text = m.group(1)
        return el, m.start(0), m.end(0)

class UExtension(Extension):
    def extendMarkdown(self, md):
        U_PATTERN = r'__(.*?)__'  # like __underline__
        md.inlinePatterns.register(UInlineProcessor(U_PATTERN, md), 'u', 175)


# for small text
# taken from https://github.com/Python-Markdown/markdown/blob/6347c57c8f309dcb0aaaa67b60d0f0039ff44484/markdown/blockprocessors.py#L284
# and modified to use `-# ` instead of `> `
class SmallTextProcessor(BlockProcessor):
    """ Process small text. """

    RE = re.compile(r'(^|\n)[ ]{0,3}-\#[ ]?(.*)')

    def test(self, parent: etree.Element, block: str) -> bool:
        return bool(self.RE.search(block)) and not util.nearing_recursion_limit()

    def run(self, parent: etree.Element, blocks: list[str]) -> None:
        block = blocks.pop(0)
        m = self.RE.search(block)
        if m:
            before = block[:m.start()]  # Lines before small
            # Pass lines before small in recursively for parsing first.
            self.parser.parseBlocks(parent, [before])
            # Remove `-# ` from beginning of each line.
            block = '\n'.join(
                [self.clean(line) for line in block[m.start():].split('\n')]
            )
        sibling = self.lastChild(parent)
        if sibling is not None and sibling.tag == "small":
            # Previous block was a small so set that as this blocks parent
            quote = sibling
        else:
            # This is a new small. Create a new parent element.
            quote = etree.SubElement(parent, 'small')
        # Recursively parse block with small as parent.
        # change parser state so smalls embedded in lists use `p` tags
        self.parser.state.set('small')
        self.parser.parseChunk(quote, block)
        self.parser.state.reset()

    def clean(self, line: str) -> str:
        """ Remove `-#` from beginning of a line. """
        m = self.RE.match(line)
        if line.strip() == "-#":
            return ""
        elif m:
            return m.group(2)
        else:
            return line


class SmallExtension(Extension):
   def extendMarkdown(self, md):
       md.parser.blockprocessors.register(SmallTextProcessor(md.parser), 'small', 175)