"""
FastAPI application entry point.

Run with:
    uvicorn app.main:app --reload --port 8000

(see backend/README.md / the project documentation for full setup steps)
"""
from __future__ import annotations

import logging
import threading
from pathlib import Path

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse

from app.infrastructure.settings import API_CORS_ORIGINS
from app.api.routers import health, brands, search, chat, catalog, system
from app.api.routers import stores, discounts, analytics as store_analytics, trending, recommendations, store_admin
from app.api.routers import nutrition, nutrition_admin, upload
from app.api.routers import auth, user_products, admin_train
from app.services.store_db import ensure_store_intelligence_schema
from app.services.nutrition_db import ensure_nutrition_schema

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
)
logger = logging.getLogger(__name__)

app = FastAPI(
    title="Brand Product Search Engine - RAG API",
    description=(
        "Local, CPU-only RAG API over an Indian FMCG product catalog stored in pgvector. "
        "Includes automated multi-store intelligence, ML discount engines, and nutrition intelligence."
    ),
    version="3.2.0",
)


@app.on_event("startup")
def _on_startup() -> None:
    # Asynchronously ensure schemas and background auto-init so server starts instantly (<1s)
    def _async_init():
        try:
            ensure_store_intelligence_schema()
            ensure_nutrition_schema()
            from app.api.routers.system import _run_background_auto_seed
            _run_background_auto_seed()
        except Exception as e:
            logger.warning("Startup background init warning: %s", e)

    threading.Thread(target=_async_init, daemon=True).start()


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

app.include_router(health.router, prefix="/api")
app.include_router(auth.router, prefix="/api")
app.include_router(user_products.router, prefix="/api")
app.include_router(admin_train.router, prefix="/api")
app.include_router(system.router, prefix="/api")
app.include_router(brands.router, prefix="/api")
app.include_router(search.router, prefix="/api")
app.include_router(chat.router, prefix="/api")
app.include_router(catalog.router, prefix="/api")
app.include_router(stores.router, prefix="/api")
app.include_router(discounts.router, prefix="/api")
app.include_router(store_analytics.router, prefix="/api")
app.include_router(trending.router, prefix="/api")
app.include_router(recommendations.router, prefix="/api")
app.include_router(store_admin.router, prefix="/api")
app.include_router(nutrition.router, prefix="/api")
app.include_router(nutrition_admin.router, prefix="/api")
app.include_router(upload.router, prefix="/api")

# Serve built frontend static files if dist exists (single-port unified deployment)
FRONTEND_DIST = Path(__file__).resolve().parents[2] / "frontend" / "dist"
if FRONTEND_DIST.exists() and (FRONTEND_DIST / "assets").exists():
    app.mount("/assets", StaticFiles(directory=str(FRONTEND_DIST / "assets")), name="assets")

    @app.get("/{full_path:path}")
    def serve_frontend(full_path: str):
        if full_path.startswith("api") or full_path.startswith("docs") or full_path.startswith("openapi.json"):
            return None
        file_path = FRONTEND_DIST / full_path
        if file_path.exists() and file_path.is_file():
            return FileResponse(file_path)
        return FileResponse(FRONTEND_DIST / "index.html")
else:
    @app.get("/")
    def root() -> dict:
        return {
            "service": "Brand Product Search Engine - RAG API",
            "docs": "/docs",
            "health": "/api/health",
            "system_status": "/api/system/status",
        }