from configparser import ConfigParser
from html import escape
from logging import getLogger
from typing import Callable, Dict
from bs4.element import Tag, PageElement

logger = getLogger("utils")


def md_escape(text: str) -> str:
    return (
        text.replace("\\", "\\\\")
        .replace("*", "\\*")
        .replace("[", "\\[")
        .replace("]", "\\]")
        .replace("_", "\\_")
        .replace("~", "\\~")
        .replace("|", "\\|")
        .replace("`", "\\`")
    )


def normalize_config(conf: ConfigParser):
    for section in conf.sections():
        _remove = set()
        for k, v in conf[section].items():
            normalized_key = k.replace(" ", "_").replace("-", "_")
            if k == normalized_key:
                continue
            logger.info(
                "moving %r.%r -> %r.%r", section, k, section, normalized_key
            )
            conf[section][normalized_key] = v
            _remove.add(k)
        for k in _remove:
            logger.info("removing key %r.%r", section, k)
            del conf[section][k]


def node_to_html(el: PageElement) -> str:
    TAG_TRANSFORMS: Dict[str, Callable[[Tag,], str]] = {
        "a": lambda tag: '<a href="{}">{}</a>'.format(
            escape(tag.attrs["href"]),
            str.join("", map(node_to_html, tag.children)),
        ),
        "p": lambda tag: (
            str.join("", map(node_to_html, tag.children)) + "\n\n"
        ),
        "i": lambda tag: (
            "<i>%s</i>" % str.join("", map(node_to_html, tag.children))
        ),
        "b": lambda tag: (
            "<b>%s</b>" % str.join("", map(node_to_html, tag.children))
        ),
        "s": lambda tag: (
            "<s>%s</s>" % str.join("", map(node_to_html, tag.children))
        ),
        "u": lambda tag: (
            "<u>%s</u>" % str.join("", map(node_to_html, tag.children))
        ),
        "pre": lambda tag: (
            "\n<pre>%s</pre>\n" % str.join("", map(node_to_html, tag.children))
        ),
        "code": lambda tag: (
            "<code>%s</code>" % str.join("", map(node_to_html, tag.children))
        ),
        "blockquote": lambda tag: "\n%s"
        % str.join(
            "\n",
            (
                "| %s" % part
                for part in str.join(
                    "", map(node_to_html, tag.children)
                ).split("\n")
            ),
        ),
        "br": lambda _: "\n",
        # NOTE may fail on nested lists
        "ul": lambda tag: (
            "\n"
            + str.join(
                "\n",
                (
                    " \u2022 "
                    + node_to_html(li).replace("\n", "\n   ").rstrip()
                    for li in tag.children
                ),
            )
            + "\n"
        ),
        "ol": lambda tag: (
            "\n"
            + str.join(
                "\n",
                (
                    "%d. %s"
                    % (i, node_to_html(li).replace("\n", "\n   ").rstrip())
                    for i, li in enumerate(tag.children, 1)
                ),
            )
            + "\n"
        ),
    }

    TAG_SUBSTITUTIONS: Dict[str, str] = {
        "strong": "b",
        "em": "i",
        "del": "s",
        "ins": "u",
    }

    if isinstance(el, Tag):
        if el.name in TAG_TRANSFORMS:
            return TAG_TRANSFORMS[el.name](el)
        if el.name in TAG_SUBSTITUTIONS:
            sub = TAG_SUBSTITUTIONS[el.name]
            if sub in TAG_TRANSFORMS:
                return TAG_TRANSFORMS[sub](el)
        return str.join("", map(node_to_html, el.children))
    return escape(str(el))


def node_to_markdown(el: PageElement) -> str:
    TAG_TRANSFORMS: Dict[str, Callable[[Tag,], str]] = {
        "a": lambda tag: "[{}]({})".format(
            md_escape(str.join("", map(node_to_markdown, tag.children))),
            tag.attrs["href"],
        ),
        "p": lambda tag: (
            str.join("", map(node_to_markdown, tag.children)) + "\n\n"
        ),
        "i": lambda tag: (
            "_%s_" % str.join("", map(node_to_markdown, tag.children))
        ),
        "b": lambda tag: (
            "*%s*" % str.join("", map(node_to_markdown, tag.children))
        ),
        "s": lambda tag: (
            "~%s~" % str.join("", map(node_to_markdown, tag.children))
        ),
        "u": lambda tag: (
            "__%s__" % str.join("", map(node_to_markdown, tag.children))
        ),
        "pre": lambda tag: (
            "\n``%s``\n" % str.join("", map(node_to_markdown, tag.children))
        ),
        "code": lambda tag: (
            "`%s`" % str.join("", map(node_to_markdown, tag.children))
        ),
        "blockquote": lambda tag: (
            "\n%s"
            % str.join(
                "\n",
                (
                    "▍%s" % part
                    for part in str.join(
                        "", map(node_to_markdown, tag.children)
                    ).split("\n")
                ),
            )
        ),
        "br": lambda _: "\n",
        # NOTE may fail on nested lists
        "ul": lambda tag: (
            "\n%s\n"
            % str.join(
                "\n",
                (
                    " \u2022 "
                    + node_to_markdown(li).replace("\n", "\n   ").rstrip()
                    for li in tag.children
                ),
            )
        ),
        "ol": lambda tag: (
            "\n%s\n"
            % str.join(
                "\n",
                (
                    "%d. %s"
                    % (i, node_to_markdown(li).replace("\n", "\n   ").rstrip())
                    for i, li in enumerate(tag.children, 1)
                ),
            )
        ),
    }

    TAG_SUBSTITUTIONS: Dict[str, str] = {
        "strong": "b",
        "em": "i",
        "del": "s",
        "ins": "u",
    }

    if isinstance(el, Tag):
        if el.name in TAG_TRANSFORMS:
            return TAG_TRANSFORMS[el.name](el)
        if el.name in TAG_SUBSTITUTIONS:
            sub = TAG_SUBSTITUTIONS[el.name]
            if sub in TAG_TRANSFORMS:
                return TAG_TRANSFORMS[sub](el)
        return str.join("", map(node_to_markdown, el.children))
    return md_escape(str(el))


def node_to_plaintext(el: PageElement) -> str:
    if isinstance(el, Tag):
        if el.name == "a":
            return "%s (%s)" % (
                str.join("", map(node_to_plaintext, el.children)),
                el.attrs["href"],
            )
        elif el.name == "p":
            return str.join("", map(node_to_plaintext, el.children)) + "\n\n"
        elif el.name == "br":
            return "\n"
        elif el.name in ("ol", "ul"):
            children = map(node_to_plaintext, el.children)
            return "\n%s\n" % str.join(
                "\n",
                (
                    " \u2022 %s" % li.replace("\n", "\n   ").strip()
                    for li in children
                )
                if el.name == "ol"
                else (
                    "%d. %s" % (i, li.replace("\n", "\n   ").strip())
                    for i, li in enumerate(children)
                ),
            )
        return str.join("", map(node_to_plaintext, el.children))
    return str(el)