import re

NO_LETTERS = "Unknown / No letters found"


def detect_language(text: str) -> str:
    cleaned_text = re.sub(r'[\s\d\W_]+', '', text)

    if not cleaned_text:
        return NO_LETTERS

    persian_pattern = re.compile(r'[\u0600-\u06FF\u0750-\u077F\uFB50-\uFDFF\uFE70-\uFEFF]')
    english_pattern = re.compile(r'[a-zA-Z]')

    persian_count = len(persian_pattern.findall(cleaned_text))
    english_count = len(english_pattern.findall(cleaned_text))

    if persian_count > english_count:
        return "fa"
    elif english_count > persian_count:
        return "en"
    else:
        return "mixed"


def detect_digit_language(text: str):
    """Guesses the language from the digits alone: Persian digits -> "fa",
    ASCII digits -> "en", no digits -> None. Used when a text has no letters."""
    if re.search(r'[\u06F0-\u06F9\u0660-\u0669]', text):
        return "fa"
    if re.search(r'[0-9]', text):
        return "en"
    return None


def convert_fa_num_to_en(text:str) -> str:
    fa_to_en = {
        '۰':'0',
        '۱':'1',
        '۲':'2',
        '۳':'3',
        '۴':'4',
        '۵':'5',
        '۶':'6',
        '۷':'7',
        '۸':'8',
        '۹':'9',
    }
    for k, v in fa_to_en.items():
        text = text.replace(k, v)
    return text