app/app.py

"""
Sentinel Arbitrage Engine - v16.0 FINAL (Correct Mount)

The definitive, money-spinning engine. This version uses the correct
FastAPI and Socket.IO mounting strategy for guaranteed execution.
"""
import asyncio
import os
import json
import time
from contextlib import asynccontextmanager
from datetime import datetime, timezone

import httpx
import socketio
from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

# Relative imports for our package structure
from .price_fetcher import PriceFetcher
from .arbitrage_analyzer import ArbitrageAnalyzer

OPPORTUNITY_THRESHOLD = 0.0015

# --- Socket.IO Server Setup ---
# This creates the server instance that will handle all real-time communication.
sio = socketio.AsyncServer(async_mode='asgi', cors_allowed_origins='*')

# --- Background Engine ---
async def run_arbitrage_detector(price_fetcher, analyzer):
    """The core engine loop; detects opportunities and emits them via Socket.IO."""
    while True:
        try:
            await price_fetcher.update_prices_async()
            all_prices = price_fetcher.get_all_prices()
            
            for asset, prices in all_prices.items():
                pyth_price = prices.get("pyth")
                chainlink_price = prices.get("chainlink_agg")
                
                if pyth_price and chainlink_price and pyth_price > 0:
                    spread = abs(pyth_price - chainlink_price) / chainlink_price
                    if spread > OPPORTUNITY_THRESHOLD:
                        current_time = time.time()
                        # Simple throttle to avoid spamming Gemini for the same opportunity
                        if not hasattr(analyzer, 'last_call') or current_time - analyzer.last_call.get(asset, 0) > 60:
                            analyzer.last_call = getattr(analyzer, 'last_call', {})
                            analyzer.last_call[asset] = current_time

                            opportunity = {
                                "asset": asset, "pyth_price": pyth_price,
                                "chainlink_price": chainlink_price, "spread_pct": spread * 100
                            }
                            print(f"⚡️ Dislocation for {asset}: {opportunity['spread_pct']:.3f}%")
                            briefing = await analyzer.get_alpha_briefing(asset, opportunity)
                            if briefing:
                                signal = {**opportunity, **briefing, "timestamp": datetime.now(timezone.utc).isoformat()}
                                await sio.emit('new_signal', signal)
                                print(f"✅ Signal Emitted for {asset}: {signal['strategy']}")
        except Exception as e:
            print(f"❌ ERROR in engine loop: {e}")

        await asyncio.sleep(15)

# --- FastAPI Lifespan (for background task) ---
@asynccontextmanager
async def lifespan(app: FastAPI):
    print("🚀 Initializing Sentinel Arbitrage Engine v16.0...")
    async with httpx.AsyncClient() as client:
        # The background task is started using the Socket.IO server's robust method
        sio.start_background_task(
            run_arbitrage_detector,
            PriceFetcher(client),
            ArbitrageAnalyzer(client)
        )
        print("✅ Engine is online and hunting for opportunities.")
        yield
        # No explicit shutdown needed for the background task here,
        # as it's tied to the server process.

# --- FastAPI App & Final ASGI App ---
# We define the FastAPI app instance first, including its lifespan.
app = FastAPI(lifespan=lifespan)

# THE CRITICAL FIX: We mount the Socket.IO ASGI app ONTO the FastAPI app.
# This makes FastAPI the main application.
app.mount('/socket.io', socketio.ASGIApp(sio))

# THE SECOND CRITICAL FIX: We mount the StaticFiles ONTO the FastAPI app as well.
# This correctly assigns the responsibility of serving files to FastAPI.
app.mount("/", StaticFiles(directory="static", html=True), name="static")


# --- Socket.IO Event Handlers ---
@sio.event
async def connect(sid, environ):
    print(f"✅ Client connected: {sid}")

@sio.event
async def disconnect(sid):
    print(f"🔥 Client disconnected: {sid}")