from __future__ import annotations

from datetime import datetime
from typing import Any


def _group_thousands(value: str) -> str:
    parts = []
    while value:
        parts.append(value[-3:])
        value = value[:-3]
    return ".".join(reversed(parts))


def number_de(value: Any, decimals: int = 1) -> str:
    if value is None:
        return "-"
    try:
        numeric = float(value)
    except (TypeError, ValueError):
        return "-"

    sign = "-" if numeric < 0 else ""
    numeric = abs(numeric)
    raw = f"{numeric:.{decimals}f}"
    integer, _, fraction = raw.partition(".")
    grouped = _group_thousands(integer)
    return f"{sign}{grouped},{fraction}" if decimals else f"{sign}{grouped}"


def currency_de(value: Any, currency: str = "EUR") -> str:
    symbol = {"EUR": "€", "USD": "$", "GBP": "£"}.get(currency, currency)
    return f"{number_de(value, 2)} {symbol}"


def percent_de(value: Any, decimals: int = 1) -> str:
    return f"{number_de(value, decimals)} %"


def delta_de(value: Any, decimals: int = 1, suffix: str = "%") -> str:
    if value is None:
        return "-"
    numeric = float(value)
    prefix = "+" if numeric > 0 else ""
    return f"{prefix}{number_de(numeric, decimals)} {suffix}".strip()


def date_de(value: Any) -> str:
    if not value:
        return "-"
    if isinstance(value, datetime):
        dt = value
    else:
        try:
            dt = datetime.fromisoformat(str(value).replace("Z", "+00:00"))
        except ValueError:
            return str(value)
    return dt.strftime("%d.%m.%Y")


def clamp(value: Any, lower: float = 0, upper: float = 100) -> float:
    try:
        number = float(value)
    except (TypeError, ValueError):
        return lower
    return max(lower, min(upper, number))