from languages import LANG_CODES, REVERSE_LANG_CODES

extensions=("mp4", "mkv", "avi", "mov", "wmv", "flv", "webm", "lrv", "gif")

def check_video_ext(extension: str) -> bool:
    if extension.lower().strip('.') in extensions:
        return True
    return False

def normalize_language(lang: str) -> str:
    """
    Input: 'ger', 'DE', 'German', 'GERMAN'
    Output: 'German'
    """
    if not lang:
        return "Undefined"
    
    # 1. Clean the input
    query = lang.strip().lower()
    
    # 2. Check if it's already a code (e.g., 'de' or 'ger')
    if query in LANG_CODES:
        return LANG_CODES[query]
    
    # 3. Check if it's a full name (e.g., 'german')
    # We need a case-insensitive check against the names in REVERSE_LANG_CODES
    for full_name in REVERSE_LANG_CODES:
        if full_name.lower() == query:
            return full_name
            
    return "Undefined"

def normalize_lang_code(lang: str) -> str:
    """
    Input: 'ger', 'DE', 'German', 'GERMAN'
    Output: 'de' (the canonical media code (ISO 639-1))
    """
    # First, get the standard full name
    full_name = normalize_language(lang)
    
    # Then, look up that full name in the reverse table
    return REVERSE_LANG_CODES.get(full_name, "und")