import os
import asyncio
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from loguru import logger

from app.core.config import get_settings
from app.db.database import init_db
from app.api.routes.auth import router as auth_router
from app.api.routes.conversations import router as conv_router
from app.api.routes.query import router as query_router
from app.api.routes.documents import router as docs_router
from app.api.routes.audio import router as audio_router
from app.api.routes.health_admin import health_router, admin_router

settings = get_settings()
os.makedirs("./data/users", exist_ok=True)


from app.services.speech_service import get_speech_service, get_tts_service

@asynccontextmanager
async def lifespan(app: FastAPI):
    logger.info(f"Starting {settings.app_name} v{settings.app_version}")
    await init_db()
    logger.info("Main database initialised")
    
    # Preload STT and TTS models during startup to avoid latency on first request
    try:
        logger.info("Preloading Speech-to-Text (STT) model...")
        await asyncio.to_thread(get_speech_service)
        logger.info("STT model preloaded successfully")
        
        logger.info("Preloading Text-to-Speech (TTS) model...")
        await asyncio.to_thread(get_tts_service().preload, settings.tts_voice)
        logger.info("TTS model preloaded successfully")
    except Exception as e:
        logger.error(f"Failed to preload speech models during startup: {e}")
        
    # Ensure Qdrant collection and indexes exist
    try:
        from app.services.qdrant_service import get_qdrant_service
        qdrant = get_qdrant_service()
        await qdrant.ensure_collection()
        logger.info("Qdrant collection and payload indexes ensured on startup")
    except Exception as e:
        logger.error(f"Failed to initialize Qdrant collection on startup: {e}")
        
    yield
    logger.info("Shutting down")


app = FastAPI(
    title=settings.app_name,
    version=settings.app_version,
    description="Medical Knowledge RAG API — Groq · Llama 4 Scout · Qdrant · BioBERT · Cross-Encoder",
    lifespan=lifespan,
)

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

# ─── Routers ──────────────────────────────────────────────────────────────────
PREFIX = "/api/v1"
app.include_router(health_router, prefix=PREFIX)
app.include_router(auth_router, prefix=PREFIX)
app.include_router(conv_router, prefix=PREFIX)
app.include_router(query_router, prefix=PREFIX)
app.include_router(docs_router, prefix=PREFIX)
app.include_router(audio_router, prefix=PREFIX)
app.include_router(admin_router, prefix=PREFIX)


@app.get("/")
async def root():
    return {"name": settings.app_name, "version": settings.app_version, "docs": "/docs"}