from dotenv import load_dotenv
import os

# Load env vars FIRST before any other imports read them
load_dotenv()
os.environ.setdefault("HF_HOME", os.path.join(os.getcwd(), "model_cache"))

from fastapi import FastAPI, Request, Depends
from fastapi.responses import JSONResponse
from fastapi.middleware.cors import CORSMiddleware
from fastapi.middleware.httpsredirect import HTTPSRedirectMiddleware
from contextlib import asynccontextmanager

from slowapi import Limiter
from slowapi.middleware import SlowAPIMiddleware
from slowapi.util import get_remote_address
from slowapi.errors import RateLimitExceeded

import sentry_sdk
from sentry_sdk.integrations.asgi import SentryAsgiMiddleware

from routers import session, transcript, qa, auth
from ml.model_cache import ModelCache
from auth import get_current_user

load_dotenv()

if os.getenv("SENTRY_DSN"):
    sentry_sdk.init(dsn=os.getenv("SENTRY_DSN"), traces_sample_rate=0.2)

limiter = Limiter(key_func=get_remote_address, default_limits=["120/minute", "10/second"])

@asynccontextmanager
async def lifespan(app: FastAPI):
    app.state.model_cache = ModelCache()
    print("Model cache initialized.")
    yield
    print("Shutting down.")

app = FastAPI(title="FocusFlow API", version="1.0.0", lifespan=lifespan)

if os.getenv("ENV", "dev").lower() == "prod":
    app.add_middleware(HTTPSRedirectMiddleware)

app.add_middleware(SlowAPIMiddleware)
app.state.limiter = limiter

origins = os.getenv("ALLOWED_ORIGINS", "*").split(",")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=False,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Global error handler wiring
@app.exception_handler(RateLimitExceeded)
async def rate_limit_handler(request: Request, exc: RateLimitExceeded):
    return JSONResponse(
        status_code=429,
        content={"detail": "Rate limit exceeded. Please retry later."},
    )

app.add_middleware(SentryAsgiMiddleware)

app.include_router(auth.router, prefix="/auth", tags=["auth"])
app.include_router(session.router, prefix="/session", tags=["session"])
app.include_router(transcript.router, prefix="/transcript", tags=["transcript"])
app.include_router(qa.router, prefix="/qa", tags=["qa"])

@app.get("/")
def root():
    return {
        "message": "Welcome to FocusFlow API",
        "status": "online",
        "docs": "/docs",
        "health": "/health"
    }

@app.get("/health")
def health():
    return {"status": "ok", "service": "FocusFlow API"}

from ml.rag import _session_stores
@app.get("/debug/rag/{session_id}")
def debug_rag(session_id: str):
    store = _session_stores.get(session_id)
    if not store:
        return {"status": "not_found", "total_sessions": list(_session_stores.keys())}
    return {
        "status": "found",
        "ntotal": store["index"].ntotal,
        "sentences": store["sentences"],
        "timestamps": store["timestamps"],
    }