import re
import unicodedata

# Normalize Arabic lookalikes to Persian
_ARABIC_TO_PERSIAN = str.maketrans({
    'ي': 'ی',  # Arabic ya  → Persian ya
    'ك': 'ک',  # Arabic kaf → Persian kaf
    'ى': 'ی',  # Alef maqsura → Persian ya
})

_PUPPY_RE = re.compile(r'puppy|پاپی|پاپي', re.IGNORECASE | re.UNICODE)

# Rough threshold: if >15% of chars are Arabic/Persian script → Persian
_PERSIAN_BLOCK = re.compile(r'[؀-ۿ]')


def normalize(text: str) -> str:
    text = unicodedata.normalize('NFC', text)
    text = text.translate(_ARABIC_TO_PERSIAN)
    text = text.replace('‌', '').replace('‍', '')  # ZWNJ / ZWJ
    return text


def is_puppy_mentioned(text: str) -> bool:
    if not text:
        return False
    return bool(_PUPPY_RE.search(normalize(text)))


def detect_language(text: str) -> str:
    if not text:
        return 'en'
    persian_count = len(_PERSIAN_BLOCK.findall(text))
    return 'fa' if persian_count > len(text) * 0.15 else 'en'


def strip_puppy_prefix(text: str) -> str:
    """Remove 'Puppy/پاپی' name prefix from a command-style message."""
    cleaned = re.sub(
        r'^[\s]*(puppy|پاپی|پاپي)[،,:\s]+',
        '',
        normalize(text),
        flags=re.IGNORECASE | re.UNICODE,
    )
    return cleaned.strip() or text.strip()