import hashlib
import html
import re
import unicodedata

from bs4 import BeautifulSoup
from slugify import slugify

ACADEMIC_TITLES = re.compile(
    r"\b(Mag\.?(\s?\(FH\))?|Dr\.?|DI|Dipl\.-Ing\.?|Ing\.?|MMag\.?|Prof\.?|Univ\.-Prof\.?|BA|MA|BSc|MSc|MBA|LL\.?M\.?|"
    r"PhD|MAS|MPA|Bakk\.?|DDr\.?|KR|Abg\.?|Mmag\.?|MEd|BEd|Dipl\.-Päd\.?)(?=\s|,|$)",
    re.IGNORECASE,
)


def normalize(text: str) -> str:
    """Lowercase, strip accents and collapse whitespace (matches SQL lower(unaccent()))."""
    text = unicodedata.normalize("NFKD", text)
    text = "".join(c for c in text if not unicodedata.combining(c))
    return re.sub(r"\s+", " ", text).strip().lower()


def strip_titles(name: str) -> str:
    name = ACADEMIC_TITLES.sub("", name)
    name = re.sub(r"\s*,\s*", ", ", name)
    return re.sub(r"\s+", " ", name).strip(" ,")


def make_slug(*parts: str) -> str:
    return slugify(" ".join(p for p in parts if p), lowercase=True, replacements=[["ß", "ss"]])


def html_to_text(fragment: str | None) -> str:
    if not fragment:
        return ""
    return re.sub(r"\s+", " ", BeautifulSoup(html.unescape(fragment), "html.parser").get_text(" ")).strip()


def fingerprint(*parts: object) -> str:
    raw = "|".join(str(p) for p in parts)
    return hashlib.sha256(raw.encode("utf-8")).hexdigest()[:40]


LEGAL_FORMS = re.compile(
    r"\b(gesellschaft\s+m\.?\s?b\.?\s?h\.?|ges\.?\s?m\.?\s?b\.?\s?h\.?|gmbh|g\.m\.b\.h\.?|aktiengesellschaft|ag|"
    r"kommanditgesellschaft|kg|og|e\.?\s?u\.?|eg|e\.?\s?gen\.?|reg\.?\s?gen\.?\s?m\.?\s?b\.?\s?h\.?|se|ltd\.?|inc\.?|"
    r"llc|s\.?a\.?|b\.?v\.?|n\.?v\.?|& co\.?|co\.?|und co\.?|gesmbh|mbh|kgaa|plc)\b",
    re.IGNORECASE,
)


def normalize_org_name(name: str) -> str:
    """'HYPO TIROL BANK AG' == 'Hypo Tirol Bank Aktiengesellschaft' -> 'hypo tirol bank'.

    Lowercase, strip accents, quotes, punctuation and legal-form suffixes, so the same company is
    recognised across sources (side-job lists, procurement notices, donation lists, ad reports).
    """
    text = normalize(name)
    text = re.sub(r"[\"'„“”»«]", "", text)
    text = LEGAL_FORMS.sub(" ", text)
    text = re.sub(r"[^\w\s-]", " ", text)
    return re.sub(r"\s+", " ", text).strip(" -")


def firmenbuch_number(value: str | None) -> str | None:
    """'FN 306527 a', 'FN306527a', '306527a' -> '306527a' (Austrian company register number, normalised)."""
    m = re.fullmatch(r"\s*(?:FN\s*)?(\d{1,6})\s?([a-zA-Z])\s*", value or "", re.IGNORECASE)
    return f"{m.group(1)}{m.group(2).lower()}" if m else None


def format_eur_de(amount: object) -> str:
    """1234567.8 -> '1.234.567,80' (German number format; formats only the number, never the sentence)."""
    try:
        value = float(amount)  # type: ignore[arg-type]
    except (TypeError, ValueError):
        return str(amount)
    return f"{value:,.2f}".replace(",", "X").replace(".", ",").replace("X", ".")


def excerpt(text: str, limit: int = 400) -> str:
    text = re.sub(r"\s+", " ", text).strip()
    return text if len(text) <= limit else text[: limit - 1].rsplit(" ", 1)[0] + "…"