import asyncio
import json
from fastapi import FastAPI, HTTPException, Query
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import StreamingResponse
from .config import settings
from .schemas import PortfolioRequest, PortfolioResponse
from .market import DEFAULT_UNIVERSE
from .service import build_portfolio_payload

app = FastAPI(title=settings.app_name)

app.add_middleware(
    CORSMiddleware,
    allow_origins=[settings.frontend_origin, "http://localhost:5173"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.get("/health")
def health():
    return {"ok": True, "service": settings.app_name}

@app.get("/api/universe")
def universe():
    return {"tickers": DEFAULT_UNIVERSE}

@app.post("/api/portfolio", response_model=PortfolioResponse)
def portfolio(req: PortfolioRequest):
    try:
        return build_portfolio_payload(
            tickers=req.tickers,
            lookback_days=req.lookback_days,
            risk_aversion=req.risk_aversion,
            max_weight=req.max_weight,
            sector_limit=req.sector_limit,
            beta_limit=req.beta_limit,
        )
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.get("/api/stream")
async def stream(tickers: str = Query(default="AAPL,MSFT,NVDA,AMZN"), lookback_days: int = Query(default=365), risk_aversion: float = Query(default=8.0), max_weight: float = Query(default=0.35), sector_limit: float = Query(default=0.70), beta_limit: float = Query(default=1.20)):
    ticker_list = [x.strip().upper() for x in tickers.split(",") if x.strip()]

    async def event_generator():
        while True:
            try:
                payload = build_portfolio_payload(
                    tickers=ticker_list,
                    lookback_days=lookback_days,
                    risk_aversion=risk_aversion,
                    max_weight=max_weight,
                    sector_limit=sector_limit,
                    beta_limit=beta_limit,
                )
                yield f"data: {json.dumps(payload)}\n\n"
            except Exception as e:
                yield f"data: {json.dumps({'error': str(e)})}\n\n"
            await asyncio.sleep(settings.stream_interval_seconds)

    return StreamingResponse(event_generator(), media_type="text/event-stream")