from fastapi import APIRouter, Depends, Form, Request
from sqlalchemy.orm import Session

from app.auth import require_auth
from app.db import get_session
from app.routers.gui import gui_session, templates
from app.services.admin import apply_rules_retroactively, change_password

router = APIRouter()


@router.get("/admin", dependencies=[Depends(gui_session)])
def admin_page(request: Request):
    return templates.TemplateResponse(request, "admin.html", {"error": None, "success": None})


@router.post("/admin/passwort", dependencies=[Depends(gui_session)])
def admin_change_password(
    request: Request,
    alt: str = Form(...),
    neu: str = Form(...),
    neu2: str = Form(...),
):
    # UX-Regel: das Formular selbst bleibt immer sichtbar/bedienbar; Fehler
    # werden inline auf derselben Seite gemeldet statt still zu verwerfen.
    if len(neu) < 8:
        return templates.TemplateResponse(request, "admin.html", {
            "error": "Das neue Passwort muss mindestens 8 Zeichen lang sein.",
            "success": None,
        }, status_code=400)
    if neu != neu2:
        return templates.TemplateResponse(request, "admin.html", {
            "error": "Die Wiederholung stimmt nicht mit dem neuen Passwort überein.",
            "success": None,
        }, status_code=400)
    try:
        change_password(alt, neu)
    except (ValueError, RuntimeError) as exc:
        return templates.TemplateResponse(request, "admin.html", {
            "error": str(exc),
            "success": None,
        }, status_code=400)
    return templates.TemplateResponse(request, "admin.html", {
        "error": None,
        "success": "Passwort erfolgreich geändert (gilt für GUI und Grafana). "
                   "Bestehende Sitzungen bleiben angemeldet.",
    })


@router.post("/api/category-rules/apply", dependencies=[Depends(require_auth)])
def apply_category_rules(session: Session = Depends(get_session)):
    return {"categorized": apply_rules_retroactively(session)}