import re

import html2text
import markdown
from django.conf import settings
from markdown.extensions.codehilite import CodeHiliteExtension

from articles.markdown import LazyLoadingImageExtension


def build_full_absolute_url(request, url):
    if request:
        return request.build_absolute_uri(url)
    else:
        return (settings.BLOG["base_url"] + url)[::-1].replace("//", "/", 1)[::-1]


def format_article_content_for_rss(content):
    return _format_article_content(content, linenums=False)


def format_article_content_for_html(content):
    return _format_article_content(content, linenums=True)


def _format_article_content(content, linenums: bool):
    md = markdown.Markdown(
        extensions=[
            "extra",
            "admonition",
            CodeHiliteExtension(linenums=linenums, guess_lang=False),
            LazyLoadingImageExtension(),
        ]
    )
    content = re.sub(r"(\s)#(\w+)", r"\1\#\2", content)
    return md.convert(content)


def truncate_words_after_char_count(text, char_count):
    total_length = 0
    text_result = []
    for word in text.split():
        if len(word) + 1 + total_length > char_count:
            break
        text_result.append(word)
        total_length += len(word) + 1
    return " ".join(text_result) + "..."


def get_html_to_text_converter():
    converter = html2text.HTML2Text()
    converter.ignore_images = True
    converter.ignore_links = True
    converter.ignore_tables = True
    converter.ignore_emphasis = True
    return converter