"""
Telegram Login Widget validation
"""
import hmac
import hashlib
from typing import Optional, Dict, Any
from config import settings


def validate_telegram_widget(auth_data: Dict[str, Any], bot_token: Optional[str] = None) -> bool:
    """
    Validate Telegram Login Widget authentication data
    
    Args:
        auth_data: Dictionary with user data and hash from Telegram widget
        bot_token: Bot token (uses MODERATION_BOT_TOKEN if not provided)
    
    Returns:
        True if validation successful
    
    Raises:
        ValueError: If validation fails
    """
    token_to_use = bot_token or settings.MODERATION_BOT_TOKEN
    
    if not token_to_use or not isinstance(token_to_use, str) or not token_to_use.strip():
        raise ValueError('Bot token модерации не настроен (MODERATION_BOT_TOKEN)')
    
    if not auth_data or 'hash' not in auth_data:
        raise ValueError('Отсутствует hash в authData')
    
    received_hash = auth_data.pop('hash')
    
    # Clean data - remove None, empty strings, and convert all to strings
    clean_data = {}
    for key, value in auth_data.items():
        if value is not None and value != '':
            clean_data[key] = str(value)
    
    # Create data check string (sorted keys)
    data_check_arr = sorted(clean_data.items())
    data_check_string = '\n'.join(f'{key}={value}' for key, value in data_check_arr)
    
    # Create secret key
    secret_key = hmac.new(
        'WebAppData'.encode('utf-8'),
        token_to_use.encode('utf-8'),
        hashlib.sha256
    ).digest()
    
    # Calculate hash
    calculated_hash = hmac.new(
        secret_key,
        data_check_string.encode('utf-8'),
        hashlib.sha256
    ).hexdigest()
    
    # Compare hashes
    is_valid = calculated_hash == received_hash
    
    if not is_valid:
        print(f"[TelegramWidget] Hash mismatch:")
        print(f"  Calculated: {calculated_hash[:20]}...")
        print(f"  Received: {received_hash[:20]}...")
        print(f"  Data check string: {data_check_string}")
    
    return is_valid