#!/usr/bin/env python3
"""
Simplified Position Tracker

Focuses only on:
1. Detecting position changes (opened/closed/size changed)
2. Sending notifications 
3. Managing pending stop losses

Reuses existing trades table and managers.
"""

import logging
import asyncio
from datetime import datetime, timezone
from typing import Optional, Dict, Any, List

logger = logging.getLogger(__name__)

class SimplePositionTracker:
    """Simplified position tracking focused on notifications and pending SLs."""
    
    def __init__(self, trading_engine, notification_manager):
        self.trading_engine = trading_engine
        self.notification_manager = notification_manager
    
    async def check_all_position_changes(self):
        """Main method - check all positions for changes and send notifications."""
        try:
            stats = self.trading_engine.get_stats()
            if not stats:
                logger.warning("TradingStats not available")
                return
            
            # Get current exchange positions
            exchange_positions = self.trading_engine.get_positions() or []
            
            # Get current DB positions (trades with status='position_opened')
            db_positions = stats.get_open_positions()
            
            # Create lookup maps
            exchange_map = {pos['symbol']: pos for pos in exchange_positions if abs(float(pos.get('contracts', 0))) > 1e-9}
            db_map = {pos['symbol']: pos for pos in db_positions}
            
            all_symbols = set(exchange_map.keys()) | set(db_map.keys())
            
            for symbol in all_symbols:
                await self._check_symbol_position_change(symbol, exchange_map.get(symbol), db_map.get(symbol), stats)
            
            # Handle pending stop losses
            await self._handle_pending_stop_losses(stats)
            
            # Handle orphaned pending trades (orders cancelled before filling)
            await self._handle_orphaned_pending_trades(stats)
            
        except Exception as e:
            logger.error(f"❌ Error checking position changes: {e}")
    
    async def _check_symbol_position_change(self, symbol: str, exchange_pos: Optional[Dict], 
                                           db_pos: Optional[Dict], stats) -> None:
        """Check position changes for a single symbol."""
        try:
            current_time = datetime.now(timezone.utc)
            
            # Case 1: New position (exchange has, DB doesn't)
            if exchange_pos and not db_pos:
                await self._handle_position_opened(symbol, exchange_pos, stats, current_time)
            
            # Case 2: Position closed (DB has, exchange doesn't) 
            elif db_pos and not exchange_pos:
                await self._handle_position_closed(symbol, db_pos, stats, current_time)
            
            # Case 3: Position size changed (both exist, different sizes)
            elif exchange_pos and db_pos:
                await self._handle_position_size_change(symbol, exchange_pos, db_pos, stats, current_time)
            
            # Case 4: Both None - no action needed
            
        except Exception as e:
            logger.error(f"❌ Error checking position change for {symbol}: {e}")
    
    async def _handle_position_opened(self, symbol: str, exchange_pos: Dict, stats, timestamp: datetime):
        """Handle new position detection."""
        try:
            contracts = float(exchange_pos.get('contracts', 0))
            size = abs(contracts)
            
            # Use CCXT's side field first (more reliable), fallback to contract sign
            ccxt_side = exchange_pos.get('side', '').lower()
            if ccxt_side == 'long':
                side, order_side = 'long', 'buy'
            elif ccxt_side == 'short':
                side, order_side = 'short', 'sell'
            else:
                # Fallback to contract sign (less reliable but better than nothing)
                side = 'long' if contracts > 0 else 'short'
                order_side = 'buy' if side == 'long' else 'sell'
                logger.warning(f"⚠️ Using contract sign fallback for {symbol}: side={side}, ccxt_side='{ccxt_side}'")
            
            # Get entry price from exchange
            entry_price = float(exchange_pos.get('entryPrice', 0)) or float(exchange_pos.get('entryPx', 0))
            if not entry_price:
                entry_price = float(exchange_pos.get('markPrice', 0)) or float(exchange_pos.get('markPx', 0))
            
            if not entry_price:
                logger.error(f"❌ Cannot determine entry price for {symbol}")
                return
            
            # Create trade lifecycle using existing manager
            lifecycle_id = stats.create_trade_lifecycle(
                symbol=symbol,
                side=order_side,
                entry_order_id=f"external_position_{timestamp.strftime('%Y%m%d_%H%M%S')}",
                trade_type='external_detected'
            )
            
            if lifecycle_id:
                # Update to position_opened using existing manager
                success = stats.update_trade_position_opened(
                    lifecycle_id=lifecycle_id,
                    entry_price=entry_price,
                    entry_amount=size,
                    exchange_fill_id=f"position_detected_{timestamp.isoformat()}"
                )
                
                if success:
                    logger.info(f"🚀 NEW POSITION: {symbol} {side.upper()} {size} @ {entry_price}")
                    
                    # Send notification
                    await self._send_position_notification('opened', symbol, {
                        'side': side,
                        'size': size,
                        'price': entry_price,
                        'timestamp': timestamp
                    })
                    
        except Exception as e:
            logger.error(f"❌ Error handling position opened for {symbol}: {e}")
    
    async def _handle_position_closed(self, symbol: str, db_pos: Dict, stats, timestamp: datetime):
        """Handle position closure detection."""
        try:
            lifecycle_id = db_pos['trade_lifecycle_id']
            entry_price = db_pos.get('entry_price', 0)
            position_side = db_pos.get('position_side')
            size = db_pos.get('current_position_size', 0)
            
            # Estimate exit price (could be improved with recent fills)
            market_data = self.trading_engine.get_market_data(symbol)
            exit_price = entry_price  # Fallback
            if market_data and market_data.get('ticker'):
                exit_price = float(market_data['ticker'].get('last', exit_price))
            
            # Calculate realized PnL
            realized_pnl = 0
            if position_side == 'long':
                realized_pnl = size * (exit_price - entry_price)
            elif position_side == 'short':
                realized_pnl = size * (entry_price - exit_price)
            
            # Update to position_closed using existing manager
            success = stats.update_trade_position_closed(
                lifecycle_id=lifecycle_id,
                exit_price=exit_price,
                realized_pnl=realized_pnl,
                exchange_fill_id=f"position_closed_detected_{timestamp.isoformat()}"
            )
            
            if success:
                logger.info(f"🎯 POSITION CLOSED: {symbol} {position_side.upper()} PnL: {realized_pnl:.2f}")
                
                # Send notification
                await self._send_position_notification('closed', symbol, {
                    'side': position_side,
                    'size': size,
                    'entry_price': entry_price,
                    'exit_price': exit_price,
                    'realized_pnl': realized_pnl,
                    'timestamp': timestamp
                })
                
                # Clear any pending stop losses for this symbol
                stats.order_manager.cancel_pending_stop_losses_by_symbol(symbol, 'cancelled_position_closed')
                
                # Migrate trade to aggregated stats and clean up
                stats.migrate_trade_to_aggregated_stats(lifecycle_id)
                
        except Exception as e:
            logger.error(f"❌ Error handling position closed for {symbol}: {e}")
    
    async def _handle_position_size_change(self, symbol: str, exchange_pos: Dict, 
                                         db_pos: Dict, stats, timestamp: datetime):
        """Handle position size changes and position flips."""
        try:
            exchange_size = abs(float(exchange_pos.get('contracts', 0)))
            db_size = db_pos.get('current_position_size', 0)
            db_position_side = db_pos.get('position_side')
            
            # Determine current exchange position side
            ccxt_side = exchange_pos.get('side', '').lower()
            if ccxt_side == 'long':
                exchange_position_side = 'long'
            elif ccxt_side == 'short':
                exchange_position_side = 'short'
            else:
                # Fallback to contract sign
                contracts = float(exchange_pos.get('contracts', 0))
                exchange_position_side = 'long' if contracts > 0 else 'short'
                logger.warning(f"⚠️ Using contract sign fallback for side detection: {symbol}")
            
            # Check for POSITION FLIP (LONG ↔ SHORT)
            if db_position_side != exchange_position_side:
                logger.info(f"🔄 POSITION FLIP DETECTED: {symbol} {db_position_side.upper()} → {exchange_position_side.upper()}")
                
                # Handle as: close old position + open new position
                await self._handle_position_closed(symbol, db_pos, stats, timestamp)
                await self._handle_position_opened(symbol, exchange_pos, stats, timestamp)
                return
            
            # Check if size actually changed (with small tolerance)
            if abs(exchange_size - db_size) < 1e-6:
                return  # No meaningful change
            
            lifecycle_id = db_pos['trade_lifecycle_id']
            entry_price = db_pos.get('entry_price', 0)
            
            # Update position size using existing manager
            success = stats.trade_manager.update_trade_market_data(
                lifecycle_id, current_position_size=exchange_size
            )
            
            if success:
                change_type = 'increased' if exchange_size > db_size else 'decreased'
                size_diff = abs(exchange_size - db_size)
                
                logger.info(f"📊 POSITION {change_type.upper()}: {symbol} {db_size} → {exchange_size}")
                
                # Send notification  
                await self._send_position_notification(change_type, symbol, {
                    'side': db_position_side,
                    'old_size': db_size,
                    'new_size': exchange_size,
                    'size_diff': size_diff,
                    'timestamp': timestamp
                })
                
        except Exception as e:
            logger.error(f"❌ Error handling position size change for {symbol}: {e}")
    
    async def _handle_pending_stop_losses(self, stats):
        """Handle pending stop losses - place orders for positions that need them."""
        try:
            # Get positions with pending SLs using existing manager
            pending_sl_trades = stats.get_pending_stop_loss_activations()
            
            for trade in pending_sl_trades:
                symbol = trade['symbol']
                stop_price = trade['stop_loss_price']
                position_side = trade['position_side']
                lifecycle_id = trade['trade_lifecycle_id']
                
                try:
                    # Check if position still exists on exchange
                    exchange_positions = self.trading_engine.get_positions() or []
                    position_exists = any(
                        pos['symbol'] == symbol and abs(float(pos.get('contracts', 0))) > 1e-9 
                        for pos in exchange_positions
                    )
                    
                    if position_exists:
                        # Place stop loss order
                        sl_side = 'sell' if position_side == 'long' else 'buy'
                        
                        token = symbol.split('/')[0] if '/' in symbol else symbol.split(':')[0]
                        result = await self.trading_engine.execute_stop_loss_order(
                            token=token,
                            stop_price=stop_price
                        )
                        
                        if result and result.get('success'):
                            exchange_order_id = result.get('order_placed_details', {}).get('exchange_order_id')
                            if exchange_order_id:
                                # The execute_stop_loss_order already links the SL to the trade
                                logger.info(f"✅ Placed pending SL: {symbol} @ {stop_price}")
                            else:
                                logger.warning(f"⚠️ SL placed for {symbol} but no exchange_order_id returned")
                    else:
                        # Position doesn't exist, clear pending SL
                        logger.info(f"🗑️ Clearing pending SL for non-existent position: {symbol}")
                        # This will be handled by position closed detection
                        
                except Exception as e:
                    logger.error(f"❌ Error handling pending SL for {symbol}: {e}")
                    
        except Exception as e:
            logger.error(f"❌ Error handling pending stop losses: {e}")
    
    async def _handle_orphaned_pending_trades(self, stats):
        """Handle trades stuck in 'pending' status due to cancelled orders."""
        try:
            # Get all pending trades
            pending_trades = stats.get_trades_by_status('pending')
            
            if not pending_trades:
                return
                
            logger.debug(f"🔍 Checking {len(pending_trades)} pending trades for orphaned status")
            
            # Get current exchange orders for comparison
            exchange_orders = self.trading_engine.get_orders() or []
            exchange_order_ids = {order.get('id') for order in exchange_orders if order.get('id')}
            
            # Get current exchange positions
            exchange_positions = self.trading_engine.get_positions() or []
            exchange_position_symbols = {
                pos.get('symbol') for pos in exchange_positions 
                if pos.get('symbol') and abs(float(pos.get('contracts', 0))) > 1e-9
            }
            
            for trade in pending_trades:
                try:
                    lifecycle_id = trade['trade_lifecycle_id']
                    symbol = trade['symbol']
                    entry_order_id = trade.get('entry_order_id')
                    
                    # Check if this trade should be cancelled
                    should_cancel = False
                    cancel_reason = ""
                    
                    # Case 1: Entry order ID exists but order is no longer on exchange
                    if entry_order_id and entry_order_id not in exchange_order_ids:
                        # Check if a position was opened (even if order disappeared)
                        if symbol not in exchange_position_symbols:
                            should_cancel = True
                            cancel_reason = "entry_order_cancelled_no_position"
                            logger.debug(f"🗑️ Pending trade {lifecycle_id[:8]} for {symbol}: entry order {entry_order_id} no longer exists and no position opened")
                    
                    # Case 2: No entry order ID but no position exists (shouldn't happen but safety check)
                    elif not entry_order_id and symbol not in exchange_position_symbols:
                        should_cancel = True
                        cancel_reason = "no_entry_order_no_position"
                        logger.debug(f"🗑️ Pending trade {lifecycle_id[:8]} for {symbol}: no entry order ID and no position")
                    
                    # Case 3: Check if trade is very old (safety net for other edge cases)
                    else:
                        from datetime import datetime, timezone, timedelta
                        created_at_str = trade.get('timestamp')
                        if created_at_str:
                            try:
                                created_at = datetime.fromisoformat(created_at_str.replace('Z', '+00:00'))
                                if datetime.now(timezone.utc) - created_at > timedelta(hours=1):
                                    # Very old pending trade, likely orphaned
                                    if symbol not in exchange_position_symbols:
                                        should_cancel = True
                                        cancel_reason = "old_pending_trade_no_position"
                                        logger.debug(f"🗑️ Pending trade {lifecycle_id[:8]} for {symbol}: very old ({created_at}) with no position")
                            except (ValueError, TypeError) as e:
                                logger.warning(f"Could not parse timestamp for pending trade {lifecycle_id}: {e}")
                    
                    # Cancel the orphaned trade
                    if should_cancel:
                        success = stats.update_trade_cancelled(lifecycle_id, reason=cancel_reason)
                        if success:
                            logger.info(f"🗑️ Cancelled orphaned pending trade: {symbol} (Lifecycle: {lifecycle_id[:8]}) - {cancel_reason}")
                            
                            # Send a notification about the cancelled trade
                            await self._send_trade_cancelled_notification(symbol, cancel_reason, trade)
                            
                            # Migrate cancelled trade to aggregated stats
                            stats.migrate_trade_to_aggregated_stats(lifecycle_id)
                        else:
                            logger.error(f"❌ Failed to cancel orphaned pending trade: {lifecycle_id}")
                            
                except Exception as e:
                    logger.error(f"❌ Error processing pending trade {trade.get('trade_lifecycle_id', 'unknown')}: {e}")
                    
        except Exception as e:
            logger.error(f"❌ Error handling orphaned pending trades: {e}")
    
    async def _send_trade_cancelled_notification(self, symbol: str, cancel_reason: str, trade: Dict[str, Any]):
        """Send notification for cancelled trade."""
        try:
            if not self.notification_manager:
                return
            
            token = symbol.split('/')[0] if '/' in symbol else symbol.split(':')[0]
            lifecycle_id = trade['trade_lifecycle_id']
            
            # Create user-friendly reason
            reason_map = {
                'entry_order_cancelled_no_position': 'Entry order was cancelled before filling',
                'no_entry_order_no_position': 'No entry order and no position opened',
                'old_pending_trade_no_position': 'Trade was pending too long without execution'
            }
            user_reason = reason_map.get(cancel_reason, cancel_reason)
            
            message = f"""❌ <b>Trade Cancelled</b>

📊 <b>Details:</b>
• Token: {token}
• Trade ID: {lifecycle_id[:8]}...
• Reason: {user_reason}

ℹ️ <b>Status:</b> Trade was automatically cancelled due to order issues
📱 Use /positions to view current positions"""
            
            await self.notification_manager.send_generic_notification(message.strip())
            logger.debug(f"📨 Sent cancellation notification for {symbol}")
            
        except Exception as e:
            logger.error(f"❌ Error sending cancellation notification for {symbol}: {e}")
    
    async def _send_position_notification(self, change_type: str, symbol: str, details: Dict[str, Any]):
        """Send position change notification."""
        try:
            if not self.notification_manager:
                return
            
            token = symbol.split('/')[0] if '/' in symbol else symbol.split(':')[0]
            timestamp = details.get('timestamp', datetime.now(timezone.utc))
            time_str = timestamp.strftime('%H:%M:%S')
            
            from src.utils.token_display_formatter import get_formatter
            formatter = get_formatter()
            
            if change_type == 'opened':
                side = details['side'].upper()
                size = details['size']
                price = details['price']
                
                message = f"""🚀 <b>Position Opened</b>

📊 <b>Details:</b>
• Token: {token}
• Direction: {side}
• Size: {formatter.format_amount(size, token)}
• Entry Price: {formatter.format_price_with_symbol(price, token)}
• Value: {formatter.format_price_with_symbol(size * price)}

⏰ <b>Time:</b> {time_str}
📱 Use /positions to view all positions"""
                
            elif change_type == 'closed':
                side = details['side'].upper()
                size = details['size']
                entry_price = details['entry_price']
                exit_price = details['exit_price']
                pnl = details['realized_pnl']
                pnl_emoji = "🟢" if pnl >= 0 else "🔴"
                
                message = f"""🎯 <b>Position Closed</b>

📊 <b>Details:</b>
• Token: {token}
• Direction: {side}
• Size: {formatter.format_amount(size, token)}
• Entry: {formatter.format_price_with_symbol(entry_price, token)}
• Exit: {formatter.format_price_with_symbol(exit_price, token)}

{pnl_emoji} <b>P&L:</b> {formatter.format_price_with_symbol(pnl)}

⏰ <b>Time:</b> {time_str}
📊 Use /stats to view performance"""
                
            elif change_type in ['increased', 'decreased']:
                side = details['side'].upper()
                old_size = details['old_size']
                new_size = details['new_size']
                size_diff = details['size_diff']
                emoji = "📈" if change_type == 'increased' else "📉"
                
                message = f"""{emoji} <b>Position {change_type.title()}</b>

📊 <b>Details:</b>
• Token: {token}
• Direction: {side}
• Previous Size: {formatter.format_amount(old_size, token)}
• New Size: {formatter.format_amount(new_size, token)}
• Change: {formatter.format_amount(size_diff, token)}

⏰ <b>Time:</b> {time_str}
📈 Use /positions to view current status"""
            else:
                return
                
            await self.notification_manager.send_generic_notification(message.strip())
            logger.debug(f"📨 Sent {change_type} notification for {symbol}")
            
        except Exception as e:
            logger.error(f"❌ Error sending notification for {symbol}: {e}")