main.py

"""
FastAPI Backend for Signal Engine
Complete trading signals platform with ML predictions, user auth, and real-time data
"""

from fastapi import FastAPI, HTTPException, Depends, Header, Request, WebSocket, WebSocketDisconnect
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from fastapi.staticfiles import StaticFiles
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
import websockets
import json
import asyncio
from pydantic import BaseModel, Field
from typing import List, Optional, Dict
from datetime import datetime, timedelta
import secrets
import hashlib
import hmac
import stripe
import aiohttp
import numpy as np
from sklearn.ensemble import RandomForestClassifier, GradientBoostingClassifier
from sklearn.svm import SVC
from sklearn.linear_model import LogisticRegression
from eth_account import Account
from eth_account.messages import encode_defunct
from eth_utils import to_checksum_address
from web3 import Web3
from web3.middleware import geth_poa_middleware

from database import get_session, Symbol, PredictionBatch, Prediction, LedgerEntry, Subscriber, ApiUsage
from signal_engine import SignalEngine
from config import settings
from ml_engine import MLEngine, ReinforcementLearningAgent, GeneticAlgorithmOptimizer, SelfLearningSystem

app = FastAPI(
    title="Signal Engine API",
    description="Gate.io crypto-perpetual signal engine with audit-grade ledger",
    version="1.0.0"
)

# CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Mount static files for landing page
app.mount("/static", StaticFiles(directory="static"), name="static")

# Initialize signal engine
signal_engine = SignalEngine()

# Initialize ML/RL Engine
ml_engine = MLEngine()
rl_agent = ReinforcementLearningAgent(state_size=10, action_size=3)
ga_optimizer = GeneticAlgorithmOptimizer(population_size=20, generations=50)
self_learning = SelfLearningSystem(ml_engine)

# Try to load pre-trained models
try:
    ml_engine.load_models()
    print("Loaded pre-trained ML models")
except:
    print("No pre-trained models found, will train on first request")

# Pydantic models
class HealthResponse(BaseModel):
    status: str
    ledger_valid: bool
    latest_batch: Optional[str]
    total_predictions: int

class PredictionResponse(BaseModel):
    symbol: str
    target_hour: str
    entry_price: float
    direction: str
    probability_up: float
    confidence: float
    suggested_position: float

class CurrentPredictionsResponse(BaseModel):
    batch_id: str
    target_hour: str
    batch_hash: str
    num_predictions: int
    avg_confidence: float
    predictions: List[PredictionResponse]

class MetricsResponse(BaseModel):
    total_predictions: int
    scored_predictions: int
    overall_accuracy: float
    avg_brier_score: float
    avg_hypothetical_pnl_bps: float

class AccuracyResponse(BaseModel):
    window_hours: int
    accuracy: float
    total_predictions: int
    correct_predictions: int

class LeaderboardEntry(BaseModel):
    symbol: str
    hit_rate: float
    total_predictions: int
    avg_hypothetical_pnl_bps: float

class TrackRecordResponse(BaseModel):
    ledger_head_hash: str
    recent_entries: List[Dict]
    total_scored_predictions: int
    overall_accuracy: float
    overall_hypothetical_pnl_bps: float

class WebhookEvent(BaseModel):
    type: str
    data: Dict

class WalletConnectRequest(BaseModel):
    address: str
    signature: str
    message: str

class ZKLoginRequest(BaseModel):
    challenge: str
    proof: Dict
    public_key: str

class PredictionRequest(BaseModel):
    symbol: str
    timeframe: str = "1h"

class ContractSubscription(BaseModel):
    tier: str  # FREE, PRO, ENTERPRISE
    duration: int  # months

# Authentication
def verify_api_key(x_api_key: str = Header(...)) -> Subscriber:
    """Verify API key and return subscriber"""
    session = get_session(settings.database_url)
    
    # Hash the provided key for comparison
    key_hash = hashlib.sha256(x_api_key.encode()).hexdigest()
    
    subscriber = session.query(Subscriber).filter_by(
        api_key_hash=key_hash,
        active=True
    ).first()
    
    if not subscriber:
        session.close()
        raise HTTPException(status_code=401, detail="Invalid API key")
    
    # Check subscription expiry
    if subscriber.expires_at and subscriber.expires_at < datetime.utcnow():
        session.close()
        raise HTTPException(status_code=403, detail="Subscription expired")
    
    session.close()
    return subscriber

def check_rate_limit(subscriber: Subscriber):
    """Check rate limit for subscriber"""
    session = get_session(settings.database_url)
    
    # Get rate limit based on tier
    rate_limits = {
        'free': settings.free_tier_rate_limit,
        'pro': settings.pro_tier_rate_limit,
        'enterprise': settings.enterprise_tier_rate_limit
    }
    limit = rate_limits.get(subscriber.tier, settings.free_tier_rate_limit)
    
    # Count requests in last hour
    one_hour_ago = datetime.utcnow() - timedelta(hours=1)
    usage_count = session.query(ApiUsage).filter(
        ApiUsage.subscriber_id == subscriber.id,
        ApiUsage.timestamp >= one_hour_ago
    ).count()
    
    session.close()
    
    if usage_count >= limit:
        raise HTTPException(status_code=429, detail="Rate limit exceeded")

def log_api_usage(subscriber: Subscriber, endpoint: str, status_code: int):
    """Log API usage for rate limiting"""
    session = get_session(settings.database_url)
    
    usage = ApiUsage(
        subscriber_id=subscriber.id,
        endpoint=endpoint,
        status_code=status_code
    )
    session.add(usage)
    session.commit()
    session.close()

# Endpoints
@app.get("/")
async def root():
    """Root endpoint - serve landing page"""
    from fastapi.responses import FileResponse
    return FileResponse("static/landing.html")

@app.get("/app")
async def app_root():
    """Serve the main application"""
    from fastapi.responses import FileResponse
    return FileResponse("static/index.html")

@app.get("/health", response_model=HealthResponse)
async def health():
    """Health check endpoint"""
    session = get_session(settings.database_url)
    
    # Check ledger validity
    ledger_entries = session.query(LedgerEntry).order_by(LedgerEntry.id).all()
    ledger_valid = True
    
    for i, entry in enumerate(ledger_entries):
        if i > 0 and entry.prev_hash != ledger_entries[i-1].entry_hash:
            ledger_valid = False
            break
    
    # Get latest batch
    latest_batch = session.query(PredictionBatch).order_by(PredictionBatch.id.desc()).first()
    
    # Count total predictions
    total_predictions = session.query(Prediction).count()
    
    session.close()
    
    return HealthResponse(
        status="healthy",
        ledger_valid=ledger_valid,
        latest_batch=latest_batch.batch_id if latest_batch else None,
        total_predictions=total_predictions
    )

@app.get("/v1/predictions/current", response_model=CurrentPredictionsResponse)
async def get_current_predictions(subscriber: Subscriber = Depends(verify_api_key)):
    """Get current prediction batch"""
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    # Get latest batch
    batch = session.query(PredictionBatch).order_by(PredictionBatch.id.desc()).first()
    
    if not batch:
        session.close()
        raise HTTPException(status_code=404, detail="No predictions available")
    
    # Get predictions
    predictions = session.query(Prediction).filter_by(batch_id=batch.batch_id).all()
    
    session.close()
    
    log_api_usage(subscriber, "/v1/predictions/current", 200)
    
    return CurrentPredictionsResponse(
        batch_id=batch.batch_id,
        target_hour=batch.target_hour.isoformat(),
        batch_hash=batch.batch_hash,
        num_predictions=batch.num_predictions,
        avg_confidence=batch.avg_confidence,
        predictions=[
            PredictionResponse(
                symbol=p.symbol,
                target_hour=p.target_hour.isoformat(),
                entry_price=p.entry_price,
                direction=p.direction,
                probability_up=p.probability_up,
                confidence=p.confidence,
                suggested_position=p.suggested_position
            )
            for p in predictions
        ]
    )

@app.get("/v1/predictions/history")
async def get_prediction_history(
    subscriber: Subscriber = Depends(verify_api_key),
    limit: int = 100,
    offset: int = 0
):
    """Get historical predictions"""
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    batches = session.query(PredictionBatch).order_by(
        PredictionBatch.target_hour.desc()
    ).limit(limit).offset(offset).all()
    
    result = []
    for batch in batches:
        predictions = session.query(Prediction).filter_by(batch_id=batch.batch_id).all()
        result.append({
            'batch_id': batch.batch_id,
            'target_hour': batch.target_hour.isoformat(),
            'batch_hash': batch.batch_hash,
            'num_predictions': batch.num_predictions,
            'avg_confidence': batch.avg_confidence,
            'accuracy': batch.accuracy,
            'scored_at': batch.scored_at.isoformat() if batch.scored_at else None,
            'predictions': [
                {
                    'symbol': p.symbol,
                    'direction': p.direction,
                    'probability_up': p.probability_up,
                    'confidence': p.confidence,
                    'entry_price': p.entry_price,
                    'exit_price': p.exit_price,
                    'actual_return': p.actual_return,
                    'correct': p.correct
                }
                for p in predictions
            ]
        })
    
    session.close()
    
    log_api_usage(subscriber, "/v1/predictions/history", 200)
    
    return result

@app.get("/v1/metrics", response_model=MetricsResponse)
async def get_metrics(subscriber: Subscriber = Depends(verify_api_key)):
    """Get global metrics"""
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    total_predictions = session.query(Prediction).count()
    scored_predictions = session.query(Prediction).filter(
        Prediction.scored_at.isnot(None)
    ).count()
    
    batches = session.query(PredictionBatch).filter(
        PredictionBatch.scored_at.isnot(None)
    ).all()
    
    if batches:
        avg_accuracy = sum(b.accuracy or 0 for b in batches) / len(batches)
        avg_brier = sum(b.brier_score or 0 for b in batches) / len(batches)
        avg_pnl = sum(b.hypothetical_pnl_bps or 0 for b in batches) / len(batches)
    else:
        avg_accuracy = 0.0
        avg_brier = 0.0
        avg_pnl = 0.0
    
    session.close()
    
    log_api_usage(subscriber, "/v1/metrics", 200)
    
    return MetricsResponse(
        total_predictions=total_predictions,
        scored_predictions=scored_predictions,
        overall_accuracy=avg_accuracy,
        avg_brier_score=avg_brier,
        avg_hypothetical_pnl_bps=avg_pnl
    )

@app.get("/v1/accuracy", response_model=AccuracyResponse)
async def get_accuracy(
    subscriber: Subscriber = Depends(verify_api_key),
    window_hours: int = 24
):
    """Get accuracy over rolling window"""
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    cutoff = datetime.utcnow() - timedelta(hours=window_hours)
    
    predictions = session.query(Prediction).filter(
        Prediction.scored_at >= cutoff,
        Prediction.scored_at.isnot(None)
    ).all()
    
    total = len(predictions)
    correct = sum(1 for p in predictions if p.correct)
    
    session.close()
    
    log_api_usage(subscriber, "/v1/accuracy", 200)
    
    return AccuracyResponse(
        window_hours=window_hours,
        accuracy=correct / total if total > 0 else 0.0,
        total_predictions=total,
        correct_predictions=correct
    )

@app.get("/v1/leaderboard", response_model=List[LeaderboardEntry])
async def get_leaderboard(subscriber: Subscriber = Depends(verify_api_key)):
    """Get symbol leaderboard (pro tier only)"""
    if subscriber.tier != 'pro' and subscriber.tier != 'enterprise':
        raise HTTPException(status_code=403, detail="Pro tier required")
    
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    # Calculate per-symbol metrics
    symbols = session.query(Prediction.symbol).distinct().all()
    
    leaderboard = []
    for (symbol,) in symbols:
        predictions = session.query(Prediction).filter(
            Prediction.symbol == symbol,
            Prediction.scored_at.isnot(None)
        ).all()
        
        if predictions:
            hit_rate = sum(1 for p in predictions if p.correct) / len(predictions)
            avg_pnl = sum(
                (p.actual_return or 0) * abs(p.suggested_position) * 10000
                for p in predictions
            ) / len(predictions)
            
            leaderboard.append(LeaderboardEntry(
                symbol=symbol,
                hit_rate=hit_rate,
                total_predictions=len(predictions),
                avg_hypothetical_pnl_bps=avg_pnl - settings.maker_fee_bps
            ))
    
    # Sort by hit rate
    leaderboard.sort(key=lambda x: x.hit_rate, reverse=True)
    
    session.close()
    
    log_api_usage(subscriber, "/v1/leaderboard", 200)
    
    return leaderboard[:20]

@app.get("/v1/track-record", response_model=TrackRecordResponse)
async def get_track_record(subscriber: Subscriber = Depends(verify_api_key)):
    """Get track record with ledger info"""
    check_rate_limit(subscriber)
    
    session = get_session(settings.database_url)
    
    # Get ledger head
    ledger_head = session.query(LedgerEntry).order_by(LedgerEntry.id.desc()).first()
    
    # Get recent ledger entries
    recent_entries = session.query(LedgerEntry).order_by(
        LedgerEntry.id.desc()
    ).limit(10).all()
    
    # Calculate overall metrics
    scored_predictions = session.query(Prediction).filter(
        Prediction.scored_at.isnot(None)
    ).all()
    
    total_scored = len(scored_predictions)
    overall_accuracy = sum(1 for p in scored_predictions if p.correct) / total_scored if total_scored > 0 else 0
    overall_pnl = sum(
        (p.actual_return or 0) * abs(p.suggested_position) * 10000
        for p in scored_predictions
    ) / total_scored if total_scored > 0 else 0
    
    session.close()
    
    log_api_usage(subscriber, "/v1/track-record", 200)
    
    return TrackRecordResponse(
        ledger_head_hash=ledger_head.entry_hash if ledger_head else "",
        recent_entries=[
            {
                'entry_hash': e.entry_hash,
                'entry_type': e.entry_type,
                'timestamp': e.timestamp.isoformat()
            }
            for e in recent_entries
        ],
        total_scored_predictions=total_scored,
        overall_accuracy=overall_accuracy,
        overall_hypothetical_pnl_bps=overall_pnl - settings.maker_fee_bps
    )

@app.post("/v1/stripe/webhook")
async def stripe_webhook(request: Request):
    """Handle Stripe webhooks"""
    if not settings.stripe_webhook_secret:
        # In development, accept without verification
        payload = await request.body()
        event_data = payload.decode('utf-8')
    else:
        # Production: verify signature
        payload = await request.body()
        sig_header = request.headers.get('stripe-signature')
        
        if not sig_header:
            raise HTTPException(status_code=400, detail="No signature header")
        
        try:
            event = stripe.Webhook.construct_event(
                payload, sig_header, settings.stripe_webhook_secret
            )
        except ValueError:
            raise HTTPException(status_code=400, detail="Invalid payload")
        except stripe.error.SignatureVerificationError:
            raise HTTPException(status_code=400, detail="Invalid signature")
        
        event_data = event
    
    # Process webhook
    session = get_session(settings.database_url)
    
    # Handle subscription events
    if event_data['type'] in ['customer.subscription.created', 'customer.subscription.updated']:
        customer_id = event_data['data']['object']['customer']
        subscriber = session.query(Subscriber).filter_by(
            stripe_customer_id=customer_id
        ).first()
        
        if subscriber:
            subscriber.active = True
            # Set expiry based on subscription
            session.commit()
    
    elif event_data['type'] == 'customer.subscription.deleted':
        customer_id = event_data['data']['object']['customer']
        subscriber = session.query(Subscriber).filter_by(
            stripe_customer_id=customer_id
        ).first()
        
        if subscriber:
            subscriber.active = False
            session.commit()
    
    session.close()
    
    return {"status": "success"}

@app.post("/v1/auth/zk")
async def zk_login(request: ZKLoginRequest):
    """ZK login with zero-knowledge proof verification (demo mode)"""
    try:
        # Demo mode: Generate API key without database
        api_key = secrets.token_urlsafe(32)
        
        return {
            "api_key": api_key,
            "tier": "free",
            "identity": request.public_key,
            "message": "ZK login successful (demo mode)"
        }
    except Exception as e:
        import traceback
        error_detail = f"ZK login failed: {str(e)}\n{traceback.format_exc()}"
        print(error_detail)
        return JSONResponse(
            status_code=500,
            content={"detail": error_detail}
        )

@app.get("/v1/predictions/public")
async def get_public_predictions():
    """Get public predictions (no auth required, limited data)"""
    session = get_session(settings.database_url)
    
    # Get latest batch
    batch = session.query(PredictionBatch).order_by(PredictionBatch.id.desc()).first()
    
    if not batch:
        session.close()
        return {"predictions": [], "message": "No predictions available"}
    
    # Get predictions (limited fields for public view)
    predictions = session.query(Prediction).filter_by(batch_id=batch.batch_id).limit(5).all()
    
    session.close()
    
    return {
        "batch_id": batch.batch_id,
        "target_hour": batch.target_hour.isoformat(),
        "num_predictions": batch.num_predictions,
        "predictions": [
            {
                "symbol": p.symbol,
                "direction": p.direction,
                "confidence": round(p.confidence, 2)
            }
            for p in predictions
        ]
    }

@app.get("/v1/market/tickers")
async def get_market_tickers():
    """Get real market tickers from Gate.io REST API"""
    from gateio_client import GateIOClient
    
    try:
        async with GateIOClient() as client:
            symbols = ["BTC_USDT", "ETH_USDT", "SOL_USDT", "DOGE_USDT", "XRP_USDT"]
            tickers = []
            
            for symbol in symbols:
                ticker = await client.get_ticker(symbol)
                if ticker:
                    tickers.append({
                        "symbol": ticker["symbol"].replace("_", "/"),
                        "price": ticker["last_price"],
                        "change_24h": 0,  # Gate.io doesn't provide this directly in ticker
                        "volume_24h": ticker["volume_24h"]
                    })
            
            return {"tickers": tickers}
    except Exception as e:
        return {"tickers": [], "error": str(e)}

@app.get("/v1/market/orderbook/{symbol}")
async def get_orderbook(symbol: str):
    """Get order book from Gate.io REST API"""
    import aiohttp
    
    gate_symbol = symbol.replace("/", "_")
    url = f"https://api.gateio.ws/api/v4/futures/usdt/order_book"
    
    try:
        async with aiohttp.ClientSession() as session:
            params = {"contract": gate_symbol, "limit": 20}
            async with session.get(url, params=params) as response:
                data = await response.json()
                
                return {
                    "asks": data.get("asks", [])[:10],
                    "bids": data.get("bids", [])[:10]
                }
    except Exception as e:
        return {"asks": [], "bids": [], "error": str(e)}

# ML Prediction Generation
@app.post("/v1/predictions/generate")
async def generate_prediction(request: PredictionRequest, subscriber: Subscriber = Depends(verify_api_key)):
    """Generate ML prediction using real trained models"""
    try:
        # Fetch recent market data
        from gateio_client import GateIOClient
        
        async with GateIOClient() as client:
            candles = await client.get_candles(request.symbol, interval='1h', limit=100)
            
            if len(candles) < 50:
                raise HTTPException(status_code=400, detail="Insufficient data for prediction")
            
            # Extract features
            df = pd.DataFrame(candles, columns=['timestamp', 'volume', 'close', 'high', 'low', 'open'])
            df['timestamp'] = pd.to_datetime(df['timestamp'], unit='s')
            df.set_index('timestamp', inplace=True)
            
            features_dict = ml_engine.extract_features(df).iloc[-1].to_dict()
            
            # Generate prediction using real ML engine
            if not ml_engine.is_trained:
                # Train on the fly if not trained
                await ml_engine.train(request.symbol)
            
            prediction = ml_engine.predict(features_dict)
            
            # Get RL signal
            rl_signal = rl_agent.get_signal(features_dict)
            
            # Store in database
            session = get_session(settings.database_url)
            
            batch_id = secrets.token_hex(16)
            target_hour = datetime.utcnow() + timedelta(hours=1)
            
            pred = Prediction(
                batch_id=batch_id,
                symbol=request.symbol,
                target_hour=target_hour,
                entry_price=float(df.iloc[-1]['close']),
                direction=prediction['direction'],
                probability_up=prediction['probability_up'],
                confidence=prediction['confidence'],
                suggested_position=prediction['probability_up'] if prediction['direction'] == 'LONG' else -prediction['probability_up'],
                feature_hash=hashlib.sha256(str(features_dict).encode()).hexdigest()
            )
            
            session.add(pred)
            session.commit()
            session.close()
            
            return {
                "symbol": request.symbol,
                "direction": prediction['direction'],
                "rl_signal": rl_signal,
                "confidence": prediction['confidence'],
                "entry_price": float(df.iloc[-1]['close']),
                "probability_up": prediction['probability_up'],
                "probability_down": prediction['probability_down'],
                "target_hour": target_hour.isoformat(),
                "ensemble_weights": {
                    "random_forest": 0.3,
                    "gradient_boosting": 0.3,
                    "svm": 0.2,
                    "logistic_regression": 0.2
                }
            }
            
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/v1/ml/train")
async def train_models(symbol: str = "BTC_USDT", subscriber: Subscriber = Depends(verify_api_key)):
    """Train ML models on historical data"""
    try:
        results = await ml_engine.train(symbol)
        
        # Update self-learning system
        await self_learning.update(symbol)
        
        return {
            "status": "success",
            "symbol": symbol,
            "training_results": results,
            "performance_metrics": self_learning.get_performance_metrics()
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/v1/ml/performance")
async def get_ml_performance(subscriber: Subscriber = Depends(verify_api_key)):
    """Get ML performance metrics"""
    return self_learning.get_performance_metrics()

def extract_features(df):
    """Extract technical features from candle data"""
    features = {}
    
    # Price features
    features['close'] = df.iloc[-1]['close']
    features['high'] = df.iloc[-1]['high']
    features['low'] = df.iloc[-1]['low']
    features['volume'] = df.iloc[-1]['volume']
    
    # Returns
    df['returns'] = df['close'].pct_change()
    features['return_1h'] = df['returns'].iloc[-1]
    features['return_4h'] = df['returns'].iloc[-4:].sum()
    features['return_24h'] = df['returns'].iloc[-24:].sum()
    
    # Volatility
    features['volatility'] = df['returns'].iloc[-24:].std()
    
    # Moving averages
    features['sma_7'] = df['close'].iloc[-7:].mean()
    features['sma_24'] = df['close'].iloc[-24:].mean()
    features['ema_12'] = df['close'].ewm(span=12).mean().iloc[-1]
    
    # RSI
    delta = df['close'].diff()
    gain = (delta.where(delta > 0, 0)).rolling(window=14).mean()
    loss = (-delta.where(delta < 0, 0)).rolling(window=14).mean()
    rs = gain / loss
    features['rsi'] = 100 - (100 / (1 + rs.iloc[-1]))
    
    return features

# Portfolio Management
@app.get("/v1/portfolio")
async def get_portfolio(subscriber: Subscriber = Depends(verify_api_key)):
    """Get user portfolio"""
    session = get_session(settings.database_url)
    
    # Get user's recent predictions
    predictions = session.query(Prediction).filter_by(
        symbol='BTC_USDT'  # Filter by user's symbols
    ).order_by(Prediction.target_hour.desc()).limit(20).all()
    
    session.close()
    
    # Calculate portfolio value (mock for now)
    portfolio = {
        "total_value": 0,
        "positions": [],
        "recent_predictions": [
            {
                "symbol": p.symbol,
                "direction": p.direction,
                "confidence": p.confidence,
                "entry_price": p.entry_price,
                "target_hour": p.target_hour.isoformat()
            }
            for p in predictions
        ]
    }
    
    return portfolio

# Analytics
@app.get("/v1/analytics/performance")
async def get_performance(subscriber: Subscriber = Depends(verify_api_key)):
    """Get performance analytics"""
    session = get_session(settings.database_url)
    
    # Get scored predictions
    predictions = session.query(Prediction).filter(
        Prediction.scored_at.isnot(None)
    ).all()
    
    if not predictions:
        session.close()
        return {"accuracy": 0, "total_predictions": 0, "profitable": 0}
    
    correct = sum(1 for p in predictions if p.correct)
    accuracy = correct / len(predictions)
    
    session.close()
    
    return {
        "accuracy": round(accuracy * 100, 2),
        "total_predictions": len(predictions),
        "profitable": correct
    }

# Smart Contract Endpoints
@app.get("/v1/contract/subscription/{address}")
async def get_contract_subscription(address: str):
    """Get subscription status from smart contract"""
    try:
        # For demo, return mock data
        # In production, connect to actual deployed contract
        return {
            "subscriber": address,
            "tier": "FREE",
            "expiresAt": int(datetime.utcnow().timestamp()) + 86400 * 30,
            "active": True
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/v1/contract/purchase")
async def purchase_subscription(sub: ContractSubscription, subscriber: Subscriber = Depends(verify_api_key)):
    """Purchase subscription via smart contract"""
    try:
        # For demo, just update database tier
        session = get_session(settings.database_url)
        
        db_subscriber = session.query(Subscriber).filter_by(
            wallet_address=subscriber.wallet_address
        ).first()
        
        if db_subscriber:
            db_subscriber.tier = sub.tier.lower()
            session.commit()
        
        session.close()
        
        return {
            "status": "success",
            "tier": sub.tier,
            "message": "Subscription purchased (demo mode)"
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/v1/contract/predictions/{batch_id}")
async def get_contract_prediction(batch_id: str):
    """Get prediction verification from smart contract"""
    try:
        # For demo, return mock data
        return {
            "batchId": batch_id,
            "verified": True,
            "timestamp": int(datetime.utcnow().timestamp())
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.websocket("/ws/market")
async def websocket_market(websocket: WebSocket):
    """WebSocket endpoint for real-time Gate.io market data"""
    await websocket.accept()
    
    # Connect to Gate.io WebSocket
    gate_ws_url = "wss://api.gateio.ws/ws/v4/"
    
    try:
        async with websockets.connect(gate_ws_url) as gate_ws:
            # Subscribe to BTC/USDT ticker
            subscribe_msg = {
                "method": "ticker.subscribe",
                "params": ["BTC_USDT"],
                "id": 1
            }
            await gate_ws.send(json.dumps(subscribe_msg))
            
            # Subscribe to order book
            orderbook_msg = {
                "method": "order_book.subscribe",
                "params": ["BTC_USDT", "5", "0"],
                "id": 2
            }
            await gate_ws.send(json.dumps(orderbook_msg))
            
            # Forward messages from Gate.io to client
            while True:
                try:
                    message = await gate_ws.recv()
                    data = json.loads(message)
                    
                    # Forward relevant data to client
                    if 'result' in data or 'params' in data:
                        await websocket.send_json(data)
                        
                except websockets.exceptions.ConnectionClosed:
                    break
                    
    except Exception as e:
        print(f"WebSocket error: {e}")
    finally:
        await websocket.close()

@app.websocket("/ws/multi")
async def websocket_multi(websocket: WebSocket):
    """WebSocket endpoint for multiple symbols market data"""
    await websocket.accept()
    
    gate_ws_url = "wss://api.gateio.ws/ws/v4/"
    symbols = ["BTC_USDT", "ETH_USDT", "SOL_USDT", "DOGE_USDT", "XRP_USDT"]
    
    try:
        async with websockets.connect(gate_ws_url) as gate_ws:
            # Subscribe to multiple tickers
            for i, symbol in enumerate(symbols):
                subscribe_msg = {
                    "method": "ticker.subscribe",
                    "params": [symbol],
                    "id": i + 1
                }
                await gate_ws.send(json.dumps(subscribe_msg))
            
            # Forward messages
            while True:
                try:
                    message = await gate_ws.recv()
                    data = json.loads(message)
                    await websocket.send_json(data)
                except websockets.exceptions.ConnectionClosed:
                    break
                    
    except Exception as e:
        print(f"WebSocket error: {e}")
    finally:
        await websocket.close()

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host=settings.api_host, port=settings.api_port)