import markdown
import pathlib
import os

current_dir = pathlib.Path(__file__).parent
extensions = ['meta', 'nl2br']

with (current_dir / "base_feed.xml").open("r") as f:
    base_feed = f.read()

with (current_dir / "base_item.xml").open("r") as f:
    base_item = f.read()

def convert_case(string: str):
    while string.find("_") != -1:
        string = string.replace("_" + string[string.index("_") + 1], string[string.index("_") +1].upper())

    return string

def convert_markdown_to_html(article_path: pathlib.Path):
    with (article_path / "article.md").open("r") as f:
        markdown_data = f.read()

    markdown_instance = markdown.Markdown(extensions=extensions)
    html = markdown_instance.convert(markdown_data)
    metadata = markdown_instance.Meta
    return html, metadata

def article_to_xml(article_path: pathlib.Path):
    try:
        html, metadata = convert_markdown_to_html(article_path)

    except Exception as e:
        print(e)
        return ""

    tags = [f"<{convert_case(key)}>{metadata[key][0]}</{convert_case(key)}>" for key in metadata.keys()]
    tags.append(f"<description>\n{html}\n</description>")
    return base_item.format(tags="\n".join(tags))

def make_rss_feed(path, channel_name, channel_link, description):
    article_paths = (pathlib.Path.cwd() / path).glob("[0-9]*")
    article_paths_sorted = sorted(article_paths, key=lambda x: x.name, reverse=True)
    articles = "".join([article_to_xml(path) for path in article_paths_sorted])
    return base_feed \
            .replace("{title}", channel_name)       \
            .replace("{link}", channel_link)        \
            .replace("{description}", description)  \
            .replace("{items}", articles)