"""
web/app.py — FastAPI application factory.

Usage:
  from web.app import create_app
  app = create_app()
  uvicorn.run(app, host=host, port=port)

The app is created fresh per uvicorn startup (no module-level state).
Templates and static files are mounted from web/templates/ and web/static/.
"""

from contextlib import asynccontextmanager
from pathlib import Path

import jinja2
from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates

from web import db as webdb
from web.routes import auth, dashboard, config_routes, users

_WEB_DIR = Path(__file__).parent


@asynccontextmanager
async def _lifespan(app: FastAPI):
    webdb.init_db()
    yield


def create_app() -> FastAPI:
    app = FastAPI(title="ULPgrammer", lifespan=_lifespan)

    # Use a custom Environment with caching disabled.
    # Jinja2's LRUCache has a Python 3.14 hashability issue with its cache key;
    # cache_size=0 disables the LRUCache code path entirely.
    _env = jinja2.Environment(
        loader=jinja2.FileSystemLoader(str(_WEB_DIR / "templates")),
        autoescape=jinja2.select_autoescape(),
        cache_size=0,
    )
    app.state.templates = Jinja2Templates(env=_env)

    # Static files
    app.mount("/static", StaticFiles(directory=str(_WEB_DIR / "static")), name="static")

    # Routers
    app.include_router(auth.router)
    app.include_router(dashboard.router)
    app.include_router(config_routes.router)
    app.include_router(users.router)

    return app