app/app.py

"""
Sentinel Arbitrage Engine - v17.0 FINAL (Flat Structure)

This definitive version uses a flat project structure and direct imports
to conform to the environment's startup command, ensuring a successful launch.
"""
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

# --- DIRECT IMPORTS FOR FLAT STRUCTURE ---
from price_fetcher import PriceFetcher
from arbitrage_analyzer import ArbitrageAnalyzer

OPPORTUNITY_THRESHOLD = 0.0015

# --- Socket.IO Server Setup ---
sio = socketio.AsyncServer(async_mode='asgi', cors_allowed_origins='*')

# --- Background Engine ---
async def run_arbitrage_detector(price_fetcher, analyzer):
    # This logic is correct and does not need to change.
    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, chainlink_price = prices.get("pyth"), 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()
                        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 App & Lifespan ---
# We now define the main 'app' object first.
app = FastAPI()

@app.on_event("startup")
async def startup_event():
    print("🚀 Initializing Sentinel Arbitrage Engine v17.0...")
    # Using the older startup event which is more compatible with some environments
    app.state.client = httpx.AsyncClient()
    price_fetcher = PriceFetcher(app.state.client)
    arbitrage_analyzer = ArbitrageAnalyzer(app.state.client)
    # Start the background task
    sio.background_task = sio.start_background_task(run_arbitrage_detector, price_fetcher, arbitrage_analyzer)
    print("✅ Engine is online and hunting for opportunities.")

@app.on_event("shutdown")
async def shutdown_event():
    print("⏳ Shutting down engine...")
    sio.background_task.cancel()
    await app.state.client.aclose()
    print("Engine shut down gracefully.")

# --- 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}")

# --- Mount the apps ---
# The primary app is the Socket.IO server, which wraps our FastAPI app.
app = socketio.ASGIApp(sio, other_asgi_app=app)
# Serve the static files.
sio.mount("/", StaticFiles(directory="static", html=True), name="static")