"""
Bybit exchange connector implementation.
Supports WebSocket connections to Bybit with unified trading account support.
"""

import json
import hmac
import hashlib
import time
from typing import Dict, List, Optional, Any
from datetime import datetime, timezone

from ..models.core import OrderBookSnapshot, TradeEvent, PriceLevel
from ..utils.logging import get_logger, set_correlation_id
from ..utils.exceptions import ValidationError, ConnectionError
from ..utils.validation import validate_symbol, validate_price, validate_volume
from .base_connector import BaseExchangeConnector

logger = get_logger(__name__)


class BybitConnector(BaseExchangeConnector):
    """
    Bybit WebSocket connector implementation.
    
    Supports:
    - Unified Trading Account (UTA) WebSocket streams
    - Order book streams
    - Trade streams
    - Symbol normalization
    - Authentication for private channels
    """
    
    # Bybit WebSocket URLs
    WEBSOCKET_URL = "wss://stream.bybit.com/v5/public/spot"
    WEBSOCKET_PRIVATE_URL = "wss://stream.bybit.com/v5/private"
    TESTNET_URL = "wss://stream-testnet.bybit.com/v5/public/spot"
    API_URL = "https://api.bybit.com"
    
    def __init__(self, use_testnet: bool = False, api_key: str = None, api_secret: str = None):
        """
        Initialize Bybit connector.
        
        Args:
            use_testnet: Whether to use testnet environment
            api_key: API key for authentication (optional)
            api_secret: API secret for authentication (optional)
        """
        websocket_url = self.TESTNET_URL if use_testnet else self.WEBSOCKET_URL
        super().__init__("bybit", websocket_url)
        
        # Authentication credentials (optional)
        self.api_key = api_key
        self.api_secret = api_secret
        self.use_testnet = use_testnet
        
        # Bybit-specific message handlers
        self.message_handlers.update({
            'orderbook': self._handle_orderbook_update,
            'publicTrade': self._handle_trade_update,
            'pong': self._handle_pong,
            'subscribe': self._handle_subscription_response
        })
        
        # Subscription tracking
        self.subscribed_topics = set()
        self.req_id = 1
        
        logger.info(f"Bybit connector initialized ({'testnet' if use_testnet else 'mainnet'})")
    
    def _get_message_type(self, data: Dict) -> str:
        """
        Determine message type from Bybit message data.
        
        Args:
            data: Parsed message data
            
        Returns:
            str: Message type identifier
        """
        # Bybit V5 API message format
        if 'topic' in data:
            topic = data['topic']
            if 'orderbook' in topic:
                return 'orderbook'
            elif 'publicTrade' in topic:
                return 'publicTrade'
            else:
                return topic
        elif 'op' in data:
            return data['op']  # 'subscribe', 'unsubscribe', 'ping', 'pong'
        elif 'success' in data:
            return 'response'
        
        return 'unknown'
    
    def normalize_symbol(self, symbol: str) -> str:
        """
        Normalize symbol to Bybit format.
        
        Args:
            symbol: Standard symbol format (e.g., 'BTCUSDT')
            
        Returns:
            str: Bybit symbol format (e.g., 'BTCUSDT')
        """
        # Bybit uses uppercase symbols without separators (same as Binance)
        normalized = symbol.upper().replace('-', '').replace('/', '')
        
        # Validate symbol format
        if not validate_symbol(normalized):
            raise ValidationError(f"Invalid symbol format: {symbol}", "INVALID_SYMBOL")
        
        return normalized
    
    async def subscribe_orderbook(self, symbol: str) -> None:
        """
        Subscribe to order book updates for a symbol.
        
        Args:
            symbol: Trading symbol (e.g., 'BTCUSDT')
        """
        try:
            set_correlation_id()
            normalized_symbol = self.normalize_symbol(symbol)
            topic = f"orderbook.50.{normalized_symbol}"
            
            # Create subscription message
            subscription_msg = {
                "op": "subscribe",
                "args": [topic],
                "req_id": str(self.req_id)
            }
            self.req_id += 1
            
            # Send subscription
            success = await self._send_message(subscription_msg)
            if success:
                # Track subscription
                if symbol not in self.subscriptions:
                    self.subscriptions[symbol] = []
                if 'orderbook' not in self.subscriptions[symbol]:
                    self.subscriptions[symbol].append('orderbook')
                
                self.subscribed_topics.add(topic)
                
                logger.info(f"Subscribed to order book for {symbol} on Bybit")
            else:
                logger.error(f"Failed to subscribe to order book for {symbol} on Bybit")
                
        except Exception as e:
            logger.error(f"Error subscribing to order book for {symbol}: {e}")
            raise
    
    async def subscribe_trades(self, symbol: str) -> None:
        """
        Subscribe to trade updates for a symbol.
        
        Args:
            symbol: Trading symbol (e.g., 'BTCUSDT')
        """
        try:
            set_correlation_id()
            normalized_symbol = self.normalize_symbol(symbol)
            topic = f"publicTrade.{normalized_symbol}"
            
            # Create subscription message
            subscription_msg = {
                "op": "subscribe",
                "args": [topic],
                "req_id": str(self.req_id)
            }
            self.req_id += 1
            
            # Send subscription
            success = await self._send_message(subscription_msg)
            if success:
                # Track subscription
                if symbol not in self.subscriptions:
                    self.subscriptions[symbol] = []
                if 'trades' not in self.subscriptions[symbol]:
                    self.subscriptions[symbol].append('trades')
                
                self.subscribed_topics.add(topic)
                
                logger.info(f"Subscribed to trades for {symbol} on Bybit")
            else:
                logger.error(f"Failed to subscribe to trades for {symbol} on Bybit")
                
        except Exception as e:
            logger.error(f"Error subscribing to trades for {symbol}: {e}")
            raise
    
    async def unsubscribe_orderbook(self, symbol: str) -> None:
        """
        Unsubscribe from order book updates for a symbol.
        
        Args:
            symbol: Trading symbol (e.g., 'BTCUSDT')
        """
        try:
            normalized_symbol = self.normalize_symbol(symbol)
            topic = f"orderbook.50.{normalized_symbol}"
            
            # Create unsubscription message
            unsubscription_msg = {
                "op": "unsubscribe",
                "args": [topic],
                "req_id": str(self.req_id)
            }
            self.req_id += 1
            
            # Send unsubscription
            success = await self._send_message(unsubscription_msg)
            if success:
                # Remove from tracking
                if symbol in self.subscriptions and 'orderbook' in self.subscriptions[symbol]:
                    self.subscriptions[symbol].remove('orderbook')
                    if not self.subscriptions[symbol]:
                        del self.subscriptions[symbol]
                
                self.subscribed_topics.discard(topic)
                
                logger.info(f"Unsubscribed from order book for {symbol} on Bybit")
            else:
                logger.error(f"Failed to unsubscribe from order book for {symbol} on Bybit")
                
        except Exception as e:
            logger.error(f"Error unsubscribing from order book for {symbol}: {e}")
            raise
    
    async def unsubscribe_trades(self, symbol: str) -> None:
        """
        Unsubscribe from trade updates for a symbol.
        
        Args:
            symbol: Trading symbol (e.g., 'BTCUSDT')
        """
        try:
            normalized_symbol = self.normalize_symbol(symbol)
            topic = f"publicTrade.{normalized_symbol}"
            
            # Create unsubscription message
            unsubscription_msg = {
                "op": "unsubscribe",
                "args": [topic],
                "req_id": str(self.req_id)
            }
            self.req_id += 1
            
            # Send unsubscription
            success = await self._send_message(unsubscription_msg)
            if success:
                # Remove from tracking
                if symbol in self.subscriptions and 'trades' in self.subscriptions[symbol]:
                    self.subscriptions[symbol].remove('trades')
                    if not self.subscriptions[symbol]:
                        del self.subscriptions[symbol]
                
                self.subscribed_topics.discard(topic)
                
                logger.info(f"Unsubscribed from trades for {symbol} on Bybit")
            else:
                logger.error(f"Failed to unsubscribe from trades for {symbol} on Bybit")
                
        except Exception as e:
            logger.error(f"Error unsubscribing from trades for {symbol}: {e}")
            raise
    
    async def get_symbols(self) -> List[str]:
        """
        Get list of available trading symbols from Bybit.
        
        Returns:
            List[str]: List of available symbols
        """
        try:
            import aiohttp
            
            api_url = "https://api-testnet.bybit.com" if self.use_testnet else self.API_URL
            
            async with aiohttp.ClientSession() as session:
                async with session.get(f"{api_url}/v5/market/instruments-info", 
                                     params={"category": "spot"}) as response:
                    if response.status == 200:
                        data = await response.json()
                        
                        if data.get('retCode') != 0:
                            logger.error(f"Bybit API error: {data.get('retMsg')}")
                            return []
                        
                        symbols = []
                        instruments = data.get('result', {}).get('list', [])
                        
                        for instrument in instruments:
                            if instrument.get('status') == 'Trading':
                                symbol = instrument.get('symbol', '')
                                symbols.append(symbol)
                        
                        logger.info(f"Retrieved {len(symbols)} symbols from Bybit")
                        return symbols
                    else:
                        logger.error(f"Failed to get symbols from Bybit: HTTP {response.status}")
                        return []
                        
        except Exception as e:
            logger.error(f"Error getting symbols from Bybit: {e}")
            return []
    
    async def get_orderbook_snapshot(self, symbol: str, depth: int = 20) -> Optional[OrderBookSnapshot]:
        """
        Get current order book snapshot from Bybit REST API.
        
        Args:
            symbol: Trading symbol
            depth: Number of price levels to retrieve
            
        Returns:
            OrderBookSnapshot: Current order book or None if unavailable
        """
        try:
            import aiohttp
            
            normalized_symbol = self.normalize_symbol(symbol)
            api_url = "https://api-testnet.bybit.com" if self.use_testnet else self.API_URL
            
            # Bybit supports depths: 1, 25, 50, 100, 200
            valid_depths = [1, 25, 50, 100, 200]
            api_depth = min(valid_depths, key=lambda x: abs(x - depth))
            
            url = f"{api_url}/v5/market/orderbook"
            params = {
                'category': 'spot',
                'symbol': normalized_symbol,
                'limit': api_depth
            }
            
            async with aiohttp.ClientSession() as session:
                async with session.get(url, params=params) as response:
                    if response.status == 200:
                        data = await response.json()
                        
                        if data.get('retCode') != 0:
                            logger.error(f"Bybit API error: {data.get('retMsg')}")
                            return None
                        
                        result = data.get('result', {})
                        return self._parse_orderbook_snapshot(result, symbol)
                    else:
                        logger.error(f"Failed to get order book for {symbol}: HTTP {response.status}")
                        return None
                        
        except Exception as e:
            logger.error(f"Error getting order book snapshot for {symbol}: {e}")
            return None
    
    def _parse_orderbook_snapshot(self, data: Dict, symbol: str) -> OrderBookSnapshot:
        """
        Parse Bybit order book data into OrderBookSnapshot.
        
        Args:
            data: Raw Bybit order book data
            symbol: Trading symbol
            
        Returns:
            OrderBookSnapshot: Parsed order book
        """
        try:
            # Parse bids and asks
            bids = []
            for bid_data in data.get('b', []):
                price = float(bid_data[0])
                size = float(bid_data[1])
                
                if validate_price(price) and validate_volume(size):
                    bids.append(PriceLevel(price=price, size=size))
            
            asks = []
            for ask_data in data.get('a', []):
                price = float(ask_data[0])
                size = float(ask_data[1])
                
                if validate_price(price) and validate_volume(size):
                    asks.append(PriceLevel(price=price, size=size))
            
            # Create order book snapshot
            orderbook = OrderBookSnapshot(
                symbol=symbol,
                exchange=self.exchange_name,
                timestamp=datetime.fromtimestamp(int(data.get('ts', 0)) / 1000, tz=timezone.utc),
                bids=bids,
                asks=asks,
                sequence_id=int(data.get('u', 0))
            )
            
            return orderbook
            
        except Exception as e:
            logger.error(f"Error parsing order book snapshot: {e}")
            raise ValidationError(f"Invalid order book data: {e}", "PARSE_ERROR") 
   
    async def _handle_orderbook_update(self, data: Dict) -> None:
        """
        Handle order book update from Bybit.
        
        Args:
            data: Order book update data
        """
        try:
            set_correlation_id()
            
            # Extract symbol from topic
            topic = data.get('topic', '')
            if not topic.startswith('orderbook'):
                logger.warning("Invalid orderbook topic")
                return
            
            # Extract symbol from topic: orderbook.50.BTCUSDT
            parts = topic.split('.')
            if len(parts) < 3:
                logger.warning("Invalid orderbook topic format")
                return
            
            symbol = parts[2]
            orderbook_data = data.get('data', {})
            
            # Parse bids and asks
            bids = []
            for bid_data in orderbook_data.get('b', []):
                price = float(bid_data[0])
                size = float(bid_data[1])
                
                if validate_price(price) and validate_volume(size):
                    bids.append(PriceLevel(price=price, size=size))
            
            asks = []
            for ask_data in orderbook_data.get('a', []):
                price = float(ask_data[0])
                size = float(ask_data[1])
                
                if validate_price(price) and validate_volume(size):
                    asks.append(PriceLevel(price=price, size=size))
            
            # Create order book snapshot
            orderbook = OrderBookSnapshot(
                symbol=symbol,
                exchange=self.exchange_name,
                timestamp=datetime.fromtimestamp(int(data.get('ts', 0)) / 1000, tz=timezone.utc),
                bids=bids,
                asks=asks,
                sequence_id=int(orderbook_data.get('u', 0))
            )
            
            # Notify callbacks
            self._notify_data_callbacks(orderbook)
            
            logger.debug(f"Processed order book update for {symbol}")
            
        except Exception as e:
            logger.error(f"Error handling order book update: {e}")
    
    async def _handle_trade_update(self, data: Dict) -> None:
        """
        Handle trade update from Bybit.
        
        Args:
            data: Trade update data
        """
        try:
            set_correlation_id()
            
            # Extract symbol from topic
            topic = data.get('topic', '')
            if not topic.startswith('publicTrade'):
                logger.warning("Invalid trade topic")
                return
            
            # Extract symbol from topic: publicTrade.BTCUSDT
            parts = topic.split('.')
            if len(parts) < 2:
                logger.warning("Invalid trade topic format")
                return
            
            symbol = parts[1]
            trades_data = data.get('data', [])
            
            # Process each trade
            for trade_data in trades_data:
                price = float(trade_data.get('p', 0))
                size = float(trade_data.get('v', 0))
                
                # Validate data
                if not validate_price(price) or not validate_volume(size):
                    logger.warning(f"Invalid trade data: price={price}, size={size}")
                    continue
                
                # Determine side (Bybit uses 'S' field)
                side_flag = trade_data.get('S', '')
                side = 'buy' if side_flag == 'Buy' else 'sell'
                
                # Create trade event
                trade = TradeEvent(
                    symbol=symbol,
                    exchange=self.exchange_name,
                    timestamp=datetime.fromtimestamp(int(trade_data.get('T', 0)) / 1000, tz=timezone.utc),
                    price=price,
                    size=size,
                    side=side,
                    trade_id=str(trade_data.get('i', ''))
                )
                
                # Notify callbacks
                self._notify_data_callbacks(trade)
                
                logger.debug(f"Processed trade for {symbol}: {side} {size} @ {price}")
            
        except Exception as e:
            logger.error(f"Error handling trade update: {e}")
    
    async def _handle_subscription_response(self, data: Dict) -> None:
        """
        Handle subscription response from Bybit.
        
        Args:
            data: Subscription response data
        """
        try:
            success = data.get('success', False)
            req_id = data.get('req_id', '')
            op = data.get('op', '')
            
            if success:
                logger.info(f"Bybit {op} successful (req_id: {req_id})")
            else:
                ret_msg = data.get('ret_msg', 'Unknown error')
                logger.error(f"Bybit {op} failed: {ret_msg} (req_id: {req_id})")
            
        except Exception as e:
            logger.error(f"Error handling subscription response: {e}")
    
    async def _handle_pong(self, data: Dict) -> None:
        """
        Handle pong response from Bybit.
        
        Args:
            data: Pong response data
        """
        logger.debug("Received Bybit pong")
    
    def _get_auth_signature(self, timestamp: str, recv_window: str = "5000") -> str:
        """
        Generate authentication signature for Bybit.
        
        Args:
            timestamp: Current timestamp
            recv_window: Receive window
            
        Returns:
            str: Authentication signature
        """
        if not self.api_key or not self.api_secret:
            return ""
        
        try:
            param_str = f"GET/realtime{timestamp}{self.api_key}{recv_window}"
            signature = hmac.new(
                self.api_secret.encode('utf-8'),
                param_str.encode('utf-8'),
                hashlib.sha256
            ).hexdigest()
            
            return signature
            
        except Exception as e:
            logger.error(f"Error generating auth signature: {e}")
            return ""
    
    async def _send_ping(self) -> None:
        """Send ping to keep connection alive."""
        try:
            ping_msg = {
                "op": "ping",
                "req_id": str(self.req_id)
            }
            self.req_id += 1
            
            await self._send_message(ping_msg)
            logger.debug("Sent ping to Bybit")
            
        except Exception as e:
            logger.error(f"Error sending ping: {e}")
    
    def get_bybit_stats(self) -> Dict[str, Any]:
        """Get Bybit-specific statistics."""
        base_stats = self.get_stats()
        
        bybit_stats = {
            'subscribed_topics': list(self.subscribed_topics),
            'use_testnet': self.use_testnet,
            'authenticated': bool(self.api_key and self.api_secret),
            'next_req_id': self.req_id
        }
        
        base_stats.update(bybit_stats)
        return base_stats