from itertools import takewhile, dropwhile
from typing import Optional, Any

from mwparserfromhell.nodes import Template, Text, Tag, Wikilink, ExternalLink
from mwparserfromhell.wikicode import Wikicode


def optional_set(haystack: dict, key: str, value: Optional[Any]):
    """Sets the key to value in haystack only if value is not None"""
    if value is not None:
        haystack[key] = value


def wikilink_to_json(value: Wikilink) -> dict:
    wl = {'title': str(value.title)}
    if value.text is not None:
        wl['text'] = str(value.text)
    return wl


def external_link_to_json(value: ExternalLink) -> dict:
    link = {'url': str(value.url)}
    if value.title is not None:
        link['text'] = str(value.title)
    return link


def template_to_json(value: Template) -> dict:
    parameter = []
    for p in value.params:
        parameter.append({'value': str(p)})
    return {
        'name': str(value.name),
        'parameter': parameter
    }


def get_sledrun_description(sledrun: Wikicode) -> Optional[str]:
    """Get description from sledrun"""
    for v in sledrun.get_sections(levels=[2], matches='Allgemeines', include_headings=False):
        dw = dropwhile(lambda n: isinstance(n, Template) or (isinstance(n, Text) and not str(n).strip()), v.nodes)
        tw = takewhile(lambda n: not (isinstance(n, Tag) and str(n) == '*'), dw)
        result = str(Wikicode(tw)).strip()
        if result:
            return result