"""FastAPI-App: REST-API + statisches Frontend."""
# SPDX-License-Identifier: Apache-2.0
from __future__ import annotations

import logging
from contextlib import asynccontextmanager
from pathlib import Path
from typing import Any

from fastapi import Depends, FastAPI, HTTPException, Query
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import HTMLResponse
from fastapi.staticfiles import StaticFiles
from sqlalchemy.orm import Session

from app import __version__, crud, schemas
from app.database import get_db, init_db
from app.external import lookup_book_by_isbn, lookup_book_by_title
from app.seed import seed_if_empty

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(name)s: %(message)s",
)
log = logging.getLogger("watchstack")

BASE_DIR = Path(__file__).resolve().parent
STATIC_DIR = BASE_DIR / "static"

__all__ = ["app"]


# ---------- Lifespan (init DB + seed on boot) -------------------------------

@asynccontextmanager
async def lifespan(_: FastAPI):
    init_db()
    with next(get_db()) as db:
        seed_if_empty(db)
    log.info("WatchStack %s ready", __version__)
    yield


app = FastAPI(
    title="WatchStack",
    description="Watchlist für Bücher, Serien & mehr.",
    version=__version__,
    lifespan=lifespan,
    contact={"name": "WatchStack", "url": "https://git.pkop.de/Vibecode/watchlist"},
    license_info={"name": "Apache-2.0", "url": "https://www.apache.org/licenses/LICENSE-2.0"},
)

# CORS — offen genug für lokale Beta, in Produktion via env einschränken
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")


# ---------- UI ---------------------------------------------------------------

@app.get("/", response_class=HTMLResponse, include_in_schema=False)
def root() -> HTMLResponse:
    return HTMLResponse((STATIC_DIR / "index.html").read_text(encoding="utf-8"))


# ---------- Health / Version -------------------------------------------------

@app.get("/api/health", tags=["meta"])
def health() -> dict[str, str]:
    return {"status": "ok", "service": "watchstack", "version": __version__}


# ---------- Lookups ----------------------------------------------------------

@app.get("/api/lookup/book", tags=["lookup"])
def lookup_book(
    isbn: str | None = Query(None, description="ISBN-10 oder ISBN-13"),
    title: str | None = Query(None),
) -> dict[str, Any]:
    """Schlägt Buchdaten extern nach. ISBN hat Vorrang."""
    if isbn:
        result = lookup_book_by_isbn(isbn)
    elif title:
        result = lookup_book_by_title(title)
    else:
        raise HTTPException(400, "isbn oder title erforderlich")
    if not result:
        raise HTTPException(404, "Keine Daten gefunden")
    return result


# ---------- Sortierung -------------------------------------------------------

_SORT_KEYS = {
    "updated_desc", "updated_asc",
    "title_asc", "title_desc",
    "rating_desc", "rating_asc",
    "year_desc", "year_asc",
}


# ---------- Media ------------------------------------------------------------

def _get_or_404(db: Session, media_id: int):
    """Holt einen Eintrag oder wirft 404."""
    m = crud.get_media(db, media_id)
    if not m:
        raise HTTPException(404, "Eintrag nicht gefunden")
    return m


@app.get("/api/media", response_model=list[schemas.MediaOut], tags=["media"])
def api_list_media(
    kind: str | None = Query(None, pattern="^(book|series)$"),
    status: str | None = Query(None, pattern="^(plan|reading|done|hold|dropped)$"),
    search: str | None = Query(None, max_length=200),
    genre: str | None = Query(None, max_length=60),
    tag: str | None = Query(None, max_length=40),
    sort: str = Query("updated_desc"),
    db: Session = Depends(get_db),
):
    if sort not in _SORT_KEYS:
        raise HTTPException(400, f"sort muss eines von {sorted(_SORT_KEYS)} sein")
    return crud.list_media(db, kind=kind, status=status, search=search,
                           genre=genre, tag=tag, sort=sort)


@app.post("/api/media", response_model=schemas.MediaOut, status_code=201, tags=["media"])
def api_create_media(payload: schemas.MediaCreate, db: Session = Depends(get_db)):
    return crud.create_media(db, payload)


@app.get("/api/media/{media_id}", response_model=schemas.MediaOut, tags=["media"])
def api_get_media(media_id: int, db: Session = Depends(get_db)):
    return _get_or_404(db, media_id)


@app.patch("/api/media/{media_id}", response_model=schemas.MediaOut, tags=["media"])
def api_update_media(
    media_id: int,
    payload: schemas.MediaUpdate,
    db: Session = Depends(get_db),
):
    return crud.update_media(db, _get_or_404(db, media_id), payload)


@app.delete("/api/media/{media_id}", status_code=204, tags=["media"])
def api_delete_media(media_id: int, db: Session = Depends(get_db)):
    crud.delete_media(db, _get_or_404(db, media_id))
    return None


@app.post("/api/media/{media_id}/progress", response_model=schemas.MediaOut, tags=["media"])
def api_progress(
    media_id: int,
    payload: schemas.ProgressUpdate,
    db: Session = Depends(get_db),
):
    return crud.bump_progress(db, _get_or_404(db, media_id), payload)


# ---------- Taxonomien -------------------------------------------------------

@app.get("/api/genres", response_model=list[schemas.GenreOut], tags=["taxonomy"])
def api_genres(db: Session = Depends(get_db)):
    return crud.list_genres(db)


@app.get("/api/tags", response_model=list[schemas.TagOut], tags=["taxonomy"])
def api_tags(db: Session = Depends(get_db)):
    return crud.list_tags(db)


# ---------- Statistik --------------------------------------------------------

@app.get("/api/stats", response_model=schemas.StatsResponse, tags=["stats"])
def api_stats(db: Session = Depends(get_db)):
    return crud.stats(db)