"""P42 Dashboard – FastAPI-Backend.

Liefert die API unter /api, die hochgeladenen Bilder unter /uploads
und (falls gebaut) das React-Frontend aus frontend/dist.
"""
import asyncio
import re
from contextlib import asynccontextmanager

from fastapi import Depends, FastAPI, HTTPException, Request
from fastapi.middleware.gzip import GZipMiddleware
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles

from . import auth, haushalt, kanban, links, monitoring, projects, reisen, rezept
from .auth import current_user
from .config import FRONTEND_DIST
from .tracking import track


@asynccontextmanager
async def lifespan(_: FastAPI):
    # Verlauf der Server-Auslastung (P42-S.M.) im Hintergrund sammeln
    sampler = asyncio.create_task(monitoring.sample_loop())
    # Erledigte Kanban-Aufgaben nach 14 Tagen löschen
    cleaner = asyncio.create_task(kanban.cleanup_loop())
    # Hauptstadt-Kennzeichen älterer Reise-Städte nachtragen (für den Karten-Export)
    capitals = asyncio.create_task(reisen.capitals_loop())
    yield
    sampler.cancel()
    cleaner.cancel()
    capitals.cancel()


app = FastAPI(title="P42 Dashboard", docs_url="/api/docs", openapi_url="/api/openapi.json", lifespan=lifespan)
# Komprimiert u. a. die JS-Bundles und die Weltkarte (~740 KB → ~200 KB)
app.add_middleware(GZipMiddleware, minimum_size=1000)


# ---------- Fehler einheitlich als {"error": "..."} ----------

@app.exception_handler(HTTPException)
async def http_error(_: Request, exc: HTTPException):
    return JSONResponse({"error": exc.detail}, status_code=exc.status_code)


@app.exception_handler(projects.ValidationError)
@app.exception_handler(links.ValidationError)
async def validation_error(_: Request, exc: ValueError):
    return JSONResponse({"error": str(exc)}, status_code=400)


# ---------- API ----------

app.include_router(auth.router)
app.include_router(links.router)
app.include_router(projects.router)
app.include_router(monitoring.router)
app.include_router(haushalt.router)
app.include_router(rezept.router)
app.include_router(reisen.router)
app.include_router(kanban.router)


@app.get("/api/track")
async def get_tracking(number: str = "", _: dict = Depends(current_user)):
    number = re.sub(r"\s+", "", number).upper()
    if not re.fullmatch(r"[A-Z0-9-]{6,40}", number):
        raise HTTPException(400, "Ungültige Sendungsnummer.")
    return await track(number)


@app.api_route("/api/{path:path}", methods=["GET", "POST", "PUT", "PATCH", "DELETE"], include_in_schema=False)
def api_not_found(path: str):
    raise HTTPException(404, "Nicht gefunden.")


# ---------- React-Frontend (nach `npm run build`) ----------

if (FRONTEND_DIST / "index.html").exists():
    app.mount("/assets", StaticFiles(directory=FRONTEND_DIST / "assets"), name="assets")

    @app.get("/{path:path}", include_in_schema=False)
    def spa(path: str):
        file = (FRONTEND_DIST / path).resolve()
        if path and file.is_file() and file.is_relative_to(FRONTEND_DIST.resolve()):
            return FileResponse(file)
        # Alle anderen Pfade übernimmt der React-Router
        return FileResponse(FRONTEND_DIST / "index.html", headers={"Cache-Control": "no-cache"})