"""
Telegram Mini App initData validation
"""
import hmac
import hashlib
import urllib.parse
from typing import Optional, Dict, Any
from config import settings

MAX_AUTH_AGE_SECONDS = 60 * 60  # 1 час
AUTH_AGE_TOLERANCE_SECONDS = 300  # 5 минут допуск


def validate_init_data(init_data_raw: str, bot_token: Optional[str] = None) -> Dict[str, Any]:
    """
    Validate and parse Telegram Mini App initData
    
    Args:
        init_data_raw: Raw initData string from Telegram
        bot_token: Bot token (uses MODERATION_BOT_TOKEN if not provided)
    
    Returns:
        Parsed initData payload with user data
    
    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():
        error_msg = (
            'Bot token модерации не настроен (MODERATION_BOT_TOKEN)'
            if bot_token
            else 'Bot token не настроен (TELEGRAM_BOT_TOKEN)'
        )
        print(f'[Telegram] Token error: {error_msg}')
        raise ValueError(error_msg)
    
    if not init_data_raw or not isinstance(init_data_raw, str):
        raise ValueError('initData не передан')
    
    print(f'[Telegram] validate_init_data called: hasInitData={bool(init_data_raw)}, length={len(init_data_raw)}')
    
    # Parse query string
    params = urllib.parse.parse_qs(init_data_raw)
    
    # Get hash
    hash_value = params.get('hash', [None])[0]
    if not hash_value:
        raise ValueError('Отсутствует hash в initData')
    
    # Remove hash from params
    params_without_hash = {k: v[0] for k, v in params.items() if k != 'hash'}
    
    # Create data check string (sorted keys)
    data_check_arr = sorted(params_without_hash.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(),
        token_to_use.encode(),
        hashlib.sha256
    ).digest()
    
    # Create signature
    signature = hmac.new(
        secret_key,
        data_check_string.encode(),
        hashlib.sha256
    ).hexdigest()
    
    # Compare signatures
    if signature != hash_value:
        print(f'[Telegram] Hash mismatch: calculated={signature[:20]}..., received={hash_value[:20]}...')
        raise ValueError('Неверная подпись initData')
    
    # Check auth_date if present
    auth_date_str = params_without_hash.get('auth_date')
    if auth_date_str:
        try:
            auth_date = int(auth_date_str)
            import time
            now = int(time.time())
            age = abs(now - auth_date)
            
            if age > MAX_AUTH_AGE_SECONDS:
                # Allow small tolerance in development
                if settings.IS_DEVELOPMENT and age <= MAX_AUTH_AGE_SECONDS + AUTH_AGE_TOLERANCE_SECONDS:
                    print(f'⚠️  InitData expired ({age}s), but allowing due to tolerance in development.')
                else:
                    raise ValueError(f'Данные авторизации устарели (возраст: {age}с, макс: {MAX_AUTH_AGE_SECONDS}с)')
        except ValueError:
            pass  # Invalid auth_date, skip check
    
    # Parse user data if present
    user_str = params_without_hash.get('user')
    user_data = None
    if user_str:
        import json
        try:
            user_data = json.loads(user_str)
        except json.JSONDecodeError:
            raise ValueError('Неверный формат user данных в initData')
    
    print('[Telegram] initData validation complete')
    
    return {
        'user': user_data,
        'auth_date': auth_date_str,
        'hash': hash_value,
        'raw': params_without_hash
    }


def normalize_telegram_user(user_data: Dict[str, Any]) -> Dict[str, Any]:
    """Normalize Telegram user data (handle both camelCase and snake_case)"""
    if not user_data:
        return {}
    
    normalized = {}
    
    # ID
    normalized['id'] = str(user_data.get('id') or user_data.get('id'))
    
    # Username
    normalized['username'] = user_data.get('username') or user_data.get('username')
    
    # First name
    normalized['firstName'] = user_data.get('first_name') or user_data.get('firstName')
    
    # Last name
    normalized['lastName'] = user_data.get('last_name') or user_data.get('lastName')
    
    # Photo URL
    normalized['photoUrl'] = user_data.get('photo_url') or user_data.get('photoUrl')
    
    return normalized