"""
Personalization Layer
=====================
Clusters traders by behavior and adapts strategies per user.

Detects problematic patterns:
- Overtrading (excessive frequency)
- Revenge trading (increased size after losses)
- Risk escalation patterns
- Emotional trading signals
"""

import torch
import torch.nn as nn
import numpy as np
from typing import Dict, List, Tuple
from sklearn.cluster import KMeans
from sklearn.preprocessing import StandardScaler


# Trader archetypes
TRADER_TYPES = {
    0: 'Conservative',    # Low risk, long holding periods, small positions
    1: 'Moderate',        # Balanced approach, moderate position sizes
    2: 'Aggressive',      # High risk tolerance, larger positions, shorter holding
    3: 'Scalper',         # Very short holding periods, many trades
    4: 'Swing Trader',    # Multi-day holds, trend-following
}


class TraderProfiler:
    """
    Build comprehensive trader profiles from historical behavior.
    Uses both rule-based heuristics and learned embeddings.
    """
    
    def __init__(self, n_clusters: int = 5):
        self.n_clusters = n_clusters
        self.scaler = StandardScaler()
        self.kmeans = KMeans(n_clusters=n_clusters, random_state=42, n_init=10)
        self.is_fitted = False
    
    def extract_behavior_features(self, trades: List[Dict]) -> np.ndarray:
        """
        Extract behavioral features from trade history.
        
        Each trade dict should have:
        - entry_price, exit_price, size, pnl, holding_time,
          timestamp, direction (1=long, -1=short)
        
        Returns: feature vector for this trader
        """
        if not trades:
            return np.zeros(15)
        
        pnls = [t.get('pnl', 0) for t in trades]
        sizes = [t.get('size', 0) for t in trades]
        holding_times = [t.get('holding_time', 0) for t in trades]
        
        winners = [p for p in pnls if p > 0]
        losers = [p for p in pnls if p <= 0]
        
        # Core metrics
        win_rate = len(winners) / max(len(pnls), 1)
        avg_win = np.mean(winners) if winners else 0
        avg_loss = np.mean(losers) if losers else 0
        profit_factor = abs(sum(winners)) / (abs(sum(losers)) + 1e-8)
        
        # Risk metrics
        avg_position_size = np.mean(sizes) if sizes else 0
        max_position_size = np.max(sizes) if sizes else 0
        position_size_std = np.std(sizes) if len(sizes) > 1 else 0
        
        # Timing metrics
        avg_holding_time = np.mean(holding_times) if holding_times else 0
        trade_frequency = len(trades)  # trades per period
        
        # Behavioral patterns
        consecutive_losses = self._max_consecutive_losses(pnls)
        size_after_loss = self._avg_size_after_loss(trades)
        size_after_win = self._avg_size_after_win(trades)
        revenge_ratio = size_after_loss / (size_after_win + 1e-8)
        
        # Max drawdown from trades
        cumulative_pnl = np.cumsum(pnls)
        running_max = np.maximum.accumulate(cumulative_pnl) if len(cumulative_pnl) > 0 else np.array([0])
        drawdowns = running_max - cumulative_pnl if len(cumulative_pnl) > 0 else np.array([0])
        max_drawdown = np.max(drawdowns) if len(drawdowns) > 0 else 0
        
        return np.array([
            win_rate,               # 0
            avg_win,                # 1
            avg_loss,               # 2
            profit_factor,          # 3
            avg_position_size,      # 4
            max_position_size,      # 5
            position_size_std,      # 6
            avg_holding_time,       # 7
            trade_frequency,        # 8
            consecutive_losses,     # 9
            revenge_ratio,          # 10
            max_drawdown,           # 11
            size_after_loss,        # 12
            size_after_win,         # 13
            len(trades),            # 14 - total trades
        ])
    
    def _max_consecutive_losses(self, pnls: List[float]) -> int:
        """Find maximum consecutive losing trades."""
        max_streak = 0
        current_streak = 0
        for p in pnls:
            if p <= 0:
                current_streak += 1
                max_streak = max(max_streak, current_streak)
            else:
                current_streak = 0
        return max_streak
    
    def _avg_size_after_loss(self, trades: List[Dict]) -> float:
        """Average position size after a losing trade."""
        sizes_after_loss = []
        for i in range(1, len(trades)):
            if trades[i-1].get('pnl', 0) <= 0:
                sizes_after_loss.append(trades[i].get('size', 0))
        return np.mean(sizes_after_loss) if sizes_after_loss else 0
    
    def _avg_size_after_win(self, trades: List[Dict]) -> float:
        """Average position size after a winning trade."""
        sizes_after_win = []
        for i in range(1, len(trades)):
            if trades[i-1].get('pnl', 0) > 0:
                sizes_after_win.append(trades[i].get('size', 0))
        return np.mean(sizes_after_win) if sizes_after_win else 0
    
    def fit(self, all_traders_features: np.ndarray):
        """Fit clustering model on features from multiple traders."""
        self.scaler.fit(all_traders_features)
        scaled = self.scaler.transform(all_traders_features)
        self.kmeans.fit(scaled)
        self.is_fitted = True
    
    def predict_type(self, features: np.ndarray) -> Dict:
        """Predict trader type and provide analysis."""
        if not self.is_fitted:
            # Default classification based on rules
            return self._rule_based_classification(features)
        
        scaled = self.scaler.transform(features.reshape(1, -1))
        cluster = self.kmeans.predict(scaled)[0]
        
        return {
            'cluster': int(cluster),
            'type_name': TRADER_TYPES.get(cluster, 'Unknown'),
            'features': {
                'win_rate': float(features[0]),
                'profit_factor': float(features[3]),
                'avg_holding_time': float(features[7]),
                'revenge_ratio': float(features[10]),
                'max_drawdown': float(features[11]),
            }
        }
    
    def _rule_based_classification(self, features: np.ndarray) -> Dict:
        """Rule-based trader classification when clustering isn't fitted."""
        win_rate = features[0]
        avg_holding = features[7]
        position_size = features[4]
        revenge_ratio = features[10]
        
        # Determine type
        if avg_holding < 5:  # Minutes
            trader_type = 3  # Scalper
        elif avg_holding > 1440:  # > 1 day
            trader_type = 4  # Swing
        elif position_size > 0.1:  # > 10% of portfolio
            trader_type = 2  # Aggressive
        elif position_size < 0.02:  # < 2% of portfolio
            trader_type = 0  # Conservative
        else:
            trader_type = 1  # Moderate
        
        return {
            'cluster': trader_type,
            'type_name': TRADER_TYPES[trader_type],
            'features': {
                'win_rate': float(features[0]),
                'profit_factor': float(features[3]),
                'avg_holding_time': float(features[7]),
                'revenge_ratio': float(features[10]),
                'max_drawdown': float(features[11]),
            }
        }


class BehaviorAlertSystem:
    """
    Real-time detection of problematic trading patterns.
    """
    
    def __init__(self):
        self.thresholds = {
            'overtrading_trades_per_hour': 10,
            'revenge_size_multiplier': 1.5,
            'max_consecutive_losses': 5,
            'max_drawdown_pct': 0.15,
            'tilt_detection_loss_streak': 3,
        }
    
    def analyze(self, recent_trades: List[Dict], 
                portfolio_value: float,
                time_window_hours: float = 1.0) -> Dict:
        """
        Analyze recent trading activity for behavioral issues.
        
        Returns alerts and recommendations.
        """
        alerts = []
        risk_multiplier = 1.0  # Default: no adjustment
        
        if not recent_trades:
            return {'alerts': [], 'risk_multiplier': 1.0, 'status': 'normal'}
        
        # 1. Overtrading detection
        trade_count = len(recent_trades)
        if trade_count / max(time_window_hours, 0.1) > self.thresholds['overtrading_trades_per_hour']:
            alerts.append({
                'type': 'OVERTRADING',
                'severity': 'HIGH',
                'message': f'Trading {trade_count} times in {time_window_hours}h exceeds safe threshold',
                'recommendation': 'Reduce trade frequency. Consider taking a break.',
            })
            risk_multiplier *= 0.5  # Halve recommended position sizes
        
        # 2. Revenge trading detection
        pnls = [t.get('pnl', 0) for t in recent_trades]
        sizes = [t.get('size', 0) for t in recent_trades]
        
        if len(recent_trades) >= 2:
            last_pnl = pnls[-2]
            last_size = sizes[-2]
            current_size = sizes[-1]
            
            if last_pnl < 0 and current_size > last_size * self.thresholds['revenge_size_multiplier']:
                alerts.append({
                    'type': 'REVENGE_TRADING',
                    'severity': 'CRITICAL',
                    'message': 'Position size increased significantly after a loss',
                    'recommendation': 'Avoid increasing size after losses. Maintain discipline.',
                })
                risk_multiplier *= 0.3
        
        # 3. Consecutive loss detection (tilt)
        consecutive_losses = 0
        for p in reversed(pnls):
            if p <= 0:
                consecutive_losses += 1
            else:
                break
        
        if consecutive_losses >= self.thresholds['tilt_detection_loss_streak']:
            alerts.append({
                'type': 'LOSS_STREAK',
                'severity': 'HIGH',
                'message': f'{consecutive_losses} consecutive losing trades detected',
                'recommendation': 'Consider pausing trading. Review strategy before next trade.',
            })
            risk_multiplier *= 0.5
        
        # 4. Drawdown check
        total_pnl = sum(pnls)
        drawdown_pct = abs(min(total_pnl, 0)) / (portfolio_value + 1e-8)
        
        if drawdown_pct > self.thresholds['max_drawdown_pct']:
            alerts.append({
                'type': 'EXCESSIVE_DRAWDOWN',
                'severity': 'CRITICAL',
                'message': f'Session drawdown at {drawdown_pct*100:.1f}% exceeds {self.thresholds["max_drawdown_pct"]*100}% threshold',
                'recommendation': 'Stop trading for the day. Review risk parameters.',
            })
            risk_multiplier *= 0.1
        
        status = 'normal'
        if any(a['severity'] == 'CRITICAL' for a in alerts):
            status = 'critical'
        elif alerts:
            status = 'warning'
        
        return {
            'alerts': alerts,
            'risk_multiplier': risk_multiplier,
            'status': status,
            'consecutive_losses': consecutive_losses,
            'session_drawdown_pct': drawdown_pct,
        }


class PersonalizationEngine:
    """
    Combines profiling, clustering, and alert systems
    to provide personalized trading recommendations.
    """
    
    def __init__(self):
        self.profiler = TraderProfiler()
        self.alert_system = BehaviorAlertSystem()
        
        # Strategy adaptation rules per trader type
        self.strategy_params = {
            0: {  # Conservative
                'max_position_pct': 0.02,
                'sl_atr_mult': 1.5,
                'tp_atr_mult': 2.0,
                'min_confidence': 0.7,
                'max_trades_per_day': 3,
            },
            1: {  # Moderate
                'max_position_pct': 0.05,
                'sl_atr_mult': 2.0,
                'tp_atr_mult': 3.0,
                'min_confidence': 0.6,
                'max_trades_per_day': 5,
            },
            2: {  # Aggressive
                'max_position_pct': 0.10,
                'sl_atr_mult': 2.5,
                'tp_atr_mult': 4.0,
                'min_confidence': 0.55,
                'max_trades_per_day': 10,
            },
            3: {  # Scalper
                'max_position_pct': 0.03,
                'sl_atr_mult': 0.5,
                'tp_atr_mult': 1.0,
                'min_confidence': 0.55,
                'max_trades_per_day': 50,
            },
            4: {  # Swing
                'max_position_pct': 0.08,
                'sl_atr_mult': 3.0,
                'tp_atr_mult': 5.0,
                'min_confidence': 0.65,
                'max_trades_per_day': 2,
            },
        }
    
    def get_personalized_params(self, trader_profile: Dict, 
                                behavior_alerts: Dict) -> Dict:
        """
        Get personalized trading parameters based on trader profile
        and current behavior alerts.
        """
        trader_type = trader_profile.get('cluster', 1)
        params = self.strategy_params.get(trader_type, self.strategy_params[1]).copy()
        
        # Apply risk multiplier from alerts
        risk_mult = behavior_alerts.get('risk_multiplier', 1.0)
        params['max_position_pct'] *= risk_mult
        
        # If revenge trading detected, increase minimum confidence
        if any(a['type'] == 'REVENGE_TRADING' for a in behavior_alerts.get('alerts', [])):
            params['min_confidence'] = min(params['min_confidence'] + 0.15, 0.9)
        
        # If overtrading, reduce max trades
        if any(a['type'] == 'OVERTRADING' for a in behavior_alerts.get('alerts', [])):
            params['max_trades_per_day'] = max(1, params['max_trades_per_day'] // 2)
        
        return params