"""Kleine Hilfsfunktionen fuer pvesnap (Dauer-Parsing, Slugs, Listen)."""

from __future__ import annotations

import re
import unicodedata

_DURATION_UNITS = {
    "s": 1, "sec": 1, "secs": 1, "second": 1, "seconds": 1,
    "sek": 1, "sekunde": 1, "sekunden": 1,
    "m": 60, "min": 60, "mins": 60, "minute": 60, "minutes": 60, "minuten": 60,
    "h": 3600, "hour": 3600, "hours": 3600, "std": 3600, "stunde": 3600, "stunden": 3600,
    "d": 86400, "day": 86400, "days": 86400, "t": 86400, "tag": 86400, "tage": 86400,
    "w": 604800, "week": 604800, "weeks": 604800, "woche": 604800, "wochen": 604800,
    "mo": 2592000, "month": 2592000, "months": 2592000, "monat": 2592000, "monate": 2592000,
    "y": 31536000, "year": 31536000, "years": 31536000,
    "j": 31536000, "jahr": 31536000, "jahre": 31536000,
}

_DURATION_TOKEN = re.compile(r"(\d+(?:[.,]\d+)?)\s*([a-zäöü]*)")

_NEVER = {"0", "never", "nie", "unbegrenzt", "unlimited", "off", "aus", "keine", "-"}


def parse_duration(text, default_unit="s"):
    """'2d12h' -> 216000. 0 / 'nie' / 'unbegrenzt' -> 0 (= keine Begrenzung)."""
    if text is None:
        raise ValueError("leere Zeitangabe")
    s = str(text).strip().lower()
    if not s:
        raise ValueError("leere Zeitangabe")
    if s in _NEVER:
        return 0

    total = 0.0
    pos = 0
    found = False
    for match in _DURATION_TOKEN.finditer(s):
        if match.start() != pos:
            raise ValueError("ungueltige Zeitangabe: %r" % text)
        pos = match.end()
        value = float(match.group(1).replace(",", "."))
        unit = match.group(2) or default_unit
        if unit not in _DURATION_UNITS:
            raise ValueError("unbekannte Zeiteinheit %r in %r" % (unit, text))
        total += value * _DURATION_UNITS[unit]
        found = True

    if not found or pos != len(s):
        raise ValueError("ungueltige Zeitangabe: %r" % text)
    return int(round(total))


def format_duration(seconds, zero="unbegrenzt"):
    """216000 -> '2d12h'. Ergebnis ist wieder von parse_duration lesbar."""
    seconds = int(seconds or 0)
    if seconds <= 0:
        return zero
    parts = []
    for unit, size in (("w", 604800), ("d", 86400), ("h", 3600), ("m", 60), ("s", 1)):
        if seconds >= size:
            count, seconds = divmod(seconds, size)
            parts.append("%d%s" % (count, unit))
    return "".join(parts)


def slugify(text, maxlen=20):
    """Gruppenname -> kurzer, PVE-tauglicher Bezeichner (nur a-z0-9, beginnt mit Buchstabe)."""
    # Umlaute vor der Normalisierung ersetzen - NFKD wuerde sie sonst zerlegen.
    lowered = str(text).lower()
    for umlaut, replacement in (("ä", "ae"), ("ö", "oe"), ("ü", "ue"), ("ß", "ss")):
        lowered = lowered.replace(umlaut, replacement)
    ascii_only = unicodedata.normalize("NFKD", lowered).encode("ascii", "ignore").decode("ascii")
    slug = re.sub(r"[^a-z0-9]+", "", ascii_only)
    if not slug:
        slug = "grp"
    if not slug[0].isalpha():
        slug = "g" + slug
    return slug[:maxlen]


_TRUE = {"1", "yes", "y", "true", "on", "ja", "j", "an", "ein", "enabled", "aktiv"}
_FALSE = {"0", "no", "n", "false", "off", "nein", "aus", "disabled", "inaktiv", ""}


def parse_bool(text, default=None):
    if isinstance(text, bool):
        return text
    value = str(text).strip().lower()
    if value in _TRUE:
        return True
    if value in _FALSE:
        return default if (value == "" and default is not None) else False
    raise ValueError("ungueltiger Ja/Nein-Wert: %r" % text)


def format_bool(value):
    return "yes" if value else "no"


def parse_list(text):
    """Kommagetrennte (oder per Semikolon/Whitespace getrennte) Liste -> Liste von Strings."""
    if not text:
        return []
    if isinstance(text, (list, tuple)):
        items = list(text)
    else:
        items = re.split(r"[,;\s]+", str(text))
    return [item.strip() for item in items if item and item.strip()]


def parse_vmid_list(text):
    """'100,101,105-108' -> [100, 101, 105, 106, 107, 108]."""
    result = []
    for token in parse_list(text):
        match = re.match(r"^(\d+)\s*-\s*(\d+)$", token)
        if match:
            start, end = int(match.group(1)), int(match.group(2))
            if end < start:
                start, end = end, start
            if end - start > 100000:
                raise ValueError("VMID-Bereich zu gross: %r" % token)
            result.extend(range(start, end + 1))
        elif token.isdigit():
            result.append(int(token))
        else:
            raise ValueError("ungueltige VMID: %r" % token)
    return sorted(set(result))


def format_vmid_list(vmids):
    """[100,101,102,105] -> '100-102,105' (Umkehrung von parse_vmid_list)."""
    ids = sorted(set(int(v) for v in vmids))
    if not ids:
        return ""
    chunks = []
    start = previous = ids[0]
    for vmid in ids[1:]:
        if vmid == previous + 1:
            previous = vmid
            continue
        chunks.append((start, previous))
        start = previous = vmid
    chunks.append((start, previous))
    out = []
    for begin, end in chunks:
        if end - begin >= 2:
            out.append("%d-%d" % (begin, end))
        else:
            out.extend(str(v) for v in range(begin, end + 1))
    return ",".join(out)


def truncate(text, width):
    text = str(text)
    if width <= 0:
        return ""
    if len(text) <= width:
        return text
    if width <= 1:
        return text[:width]
    return text[: width - 1] + "…"